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ADDRESS
DELIVERED BEFORE
THE BRITISH ASSOCIATION
ASSEMBLED AT BELFAST.
BY
JOHN TYNDALL, F. R. S.,
PRESIDE N T.


REVISED, WITH ADDITIONS BY THE AUTHOR, SIN(E
THE DELIVERY.
NEW YORK:
D. APPLETON AND COMPANY,
549 & 551 BROADWAY.
1874.




THE WORKS OF


Prof. JOHN              TYNDALL, LL.D., F.R.S.
I.
HEAT AS A MODE OF MOTION.
One vol., 12mo. Cloth, $2.00.
"My aim has been to rise to the level of these questions from a basis so elementary that
a person possessing any imaginative faculty and power of concentration might accoin
p-ny me."-From AUTHOR'S PREFACE.
II.
ON SOUND.
A Course of Eight Lectures delivered at the Royal Institution of Grtat
Britain. One vol. With Illustrations. I2mo. Cloth, $2.00.
" In the following pages I have tried to render the science of Acoustics interesting to
al intelligent persons, including those who do not possess any special scientific culture."
From AUTHOR'S PREFACE.
III.
FRAGMENTS OF SCIENCE FOR UNSCIENTIFIC
PEOPLE.
A Series of Detached Essays, Lectures, and Reviews. One vol., 2mo.
Cloth, $2.00.
" My motive in writing these papers was a desire to extend sympathy for science be.
yond the limits of the scientific public..... From America the impulse came which in.
duced me to gather these 'Fragments,' and to my friends in the United States I dedicate
them."-From AUTHOR'S PREFACE.
IV.
LIGHT AND ELECTRICITY.
Notes of Two Courses of Lectures before the Royal Institution of Great
Britain. One vol., I2mo. Cloth, $1.25.
"In thus clearly and sharply stating the fundamental principles of Electrical and Optical Science, Prof. Tyndall has earned the cordial thanks of all interested in education."From AMERICAN EDITOR'S PREFACE.
D. APPLETON & CO., Publishers,
349 & S51 Broadway, N. Y.




ADDRESS
DELIVERED BEFORE
THE BRITISH ASSOCIATION
ASSEMBLED AT BELFAST.
BY
JOHN TYNDALL, F. R. S.,
PRESIDE N T.


REVISED, WITH ADDITIONS BY THE AUTHOR, SINUE
THE DELIVERY.
NEW YORK:
D. APPLETON AND COMPANY,
549 & 551 BROADWAY.
1874.




"There is one God supreme over all gods, diviner than mortals,
Whose form is not like unto man's, and as unlike his nature;
But vain mortals imagine that gods like themselves are begotten,
With human sensations and voice and corporeal members;
So, if oxen or lions had hands and could work in man's fashion,
And trace out with chisel or brush their conception of Godhead,
Then would horses depict gods like horses, and oxen like oxen,
Each kind the divine with its own form and nature endowing."
XENOPHANES of Colophon (six centuries B. c.), " Supernatural Religion,"
Vol. I., p. 76.
" It were better to have no opinion of God at all, than such
an opinion as is unworthy of him; for the one is unbelief, the
other is contumely."                           BACON.




PRE FACE.


AT the request of my publishers, strengthened by the
expressed desire of many correspondents, I reprint, with a
few slight alterations, this Address.
It was written under some disadvantages this year in
the Alps, and sent by installments to the printer. When
read subsequently it proved too long for its purpose, and
several of its passages were accordingly struck out. Some
of them are here restored.
It has provoked an unexpected amount of criticism.
This, in due time, will subside; and I confidently look
forward to a calmer future for a verdict, founded not on
imaginary sins, but on the real facts of the case.
Of the numberless strictures and accusations, some of
them exceeding fierce, of which I have been, and continue
to be, the object, I refrain from speaking at any length.
To one or two of them, however, out of respect for their
sources, I would ask permission briefly to refer.
An evening paper of the first rank, after the ascription
of various more or less questionable aims and motives,
proceeds to the imputation that I permitted the cheers of
my audience to " stimulate " me to the utterance of words
which no right-minded man, without a sense of the gravest
responsibility, could employ. I trust the author of this
charge will allow me in all courtesy to assure him that the




4


PREFACE.


words ascribed by him to the spur of the moment were
written in Switzerland; that they stood in the printed copy
of the Address from which I read; that they evoked no
"cheers," but a silence far more impressive than cheers;
and that, finally, as regards both approbation and the
reverse, my course had been thought over and decided
long before I ventured to address a Belfast audience.
A writer in a most able theological journal represents
me as " patting religion on the back." The thought of
doing so is certainly his, not mine. The facts of religious
feeling are to me as certain as the facts of physics. But
the world, I hold, will have to distinguish between the
feeling and its forms, and to vary the latter in accordance
with the intellectual condition of the age.
I am unwilling to dwell upon statements ascribed to
eminent men, which may be imperfectly/reported in the
newspapers, and I therefore pass over a recent sermon attributed to the Bishop of Manchester with the remark,
that one engaged so much as he is in busy and, I doubt
not on the whole, beneficent outward life, is not likely to
be among the earliest to discern the more inward and
spiritual signs of the times, or to prepare for the condition
which they foreshadow.
In a recent speech at Dewsbury, the Dean of Manchester is reported to have expressed himself thus: "The
professor" (myself) "ended a most remarkable and eloquent speech by terming himself a material atheist." My
attention was drawn to Dean Cowie's statement by a
correspondent, who described it as standing " conspicuous
among the strange calumnies " with which my words have
been assailed. For myself I use no language which could
imply that I am hurt by such attack-. They have lost
their power to wound or injure. So likewise as regards
a resolution recently passed by the Presbytery of Belfast,
in which Prof. Huxley and myself are spoken of as




PREFACE.


5


" ignoring the existence of God, and advocating pure and
simple materialism;" had the possessive pronoun "our"
preceded " God," and had the words "what we consider"
preceded "pure," this statement would have been objectively true; but to make it so this qualification is required.
Cardinal Cullen, I am told, is also actively engaged in
erecting spiritual barriers against the intrusion of "infidelity" into Ireland. His eminence, I believe, has reason to suspect that the Catholic youth around him are not
proof to the seductions of science. Strong as he is, I
believe him to be impotent here. The youth of Ireland
will imbibe science, however slowly; they will be leavened by it, however gradually. And to its inward modifying power among Catholics themselves, rather than to
any Protestant propagandism, or other external influence,
I look for the abatement of various incongruities; among
them, of those mediaeval proceedings which, to the scandal and amazement of our nineteenth-century intelligence,
have been revived among us during the last two years.
In connection with the charge of atheism, I would
make one remark. Christian men are proved by their
writings to have their hours of weakness and of doubt, as
well as their hours of strength and of conviction; and
men like myself share, in their own way, these variations
of mood and tense. Were the religious views of many of
my assailants the only alternative ones, I do not know
how strong the claims of the doctrine of " material atheism " upon my allegiance might be. Probably they would
be very strong. But, as it is, I have noticed during years
of self-observation that it is not in hours of clearness and
vigor that this doctrine commends itself to my mind; that
in the presence of stronger and healthier thought it ever
dissolves and disappears, as offering no solution of the
mystery in which we dwell, and of which we form a part.
To coarser attacks and denunciations I pay no atten



6                     PREFACE.
tion; nor have I any real reason to complain of revilings
addressed to me, which professing Christians, as could
readily be proved, do not scruple to use toward each other.
The more agreeable task remains to me of thanking those
who have tried, however hopelessly, to keep accusation
within the bounds of justice, and who, privately, and at
some risk in public, have honored me with the expression
of their sympathy and approval.
JOHN TYNDALL.
ATHENAEUM CLUB,
September 15, 1874.




ADDRESS.
AN impulse inherent in primeval man turned his
thoughts and questionings betimes toward the sources of
natural phenomena. The same impulse, inherited and intensified, is the spur of scientific action to-day. Determined by it, by a process of abstraction from experience
we form physical theories which lie beyond the pale of experience, but which satisfy the desire of the mind to see
every natural occurrence resting upon a cause. In forming their notions of the origin of things, our earliest historic (and doubtless, we might add, our prehistoric) ancestors pursued, as far as their intelligence permitted, the
same course. They also fell back upon experience, but
with this difference-that the particular experiences which
furnished the weft and woof of their theories were drawn,
not from the study of Nature, but from what lay much
closer to them, the observation of men. Their theories
accordingly took an anthropomorphic form. To supersensual beings, which, "however potent and invisible, were
nothing but a species of human creatures, perhaps raised
from among mankind, and retaining all human passions
and appetites," 1 were handed over the rule and governance of natural phenomena.
Tested by observation and reflection, these early notions failed in the long-run to satisfy the more penetrating
1 Hume, "Natural History of Religion."




8


PROFESSOR TYNDALL'S


intellects of our race. Far in the depths of history we
find men of exceptional power differentiating themselves
from the crowd, rejecting these anthropomorphic notions,
and seeking to connect natural phenomena with their physical principles. But long prior to these purer efforts of
the understanding the merchant had been abroad, and
rendered the philosopher possible; commerce had been
developed, wealth amassed, leisure for travel and speculation secured, while races educated under different conditions, and therefore differently informed and endowed,
had been stimulated and sharpened by mutual contact.
In those regions where the commercial aristocracy of ancient Greece mingled with its Eastern neighbors, the
sciences were born, being nurtured and developed by freethinking and courageous men. The state of things to be
displaced may be gathered from a passage of Euripides
quoted by Hume: "There is nothing in the world; no
glory, no prosperity. The gods toss all into confusion;
mix every thing with its reverse, that all of us, from our
ignorance and uncertainty, may pay them the more worship and reverence." Now, as science demands the radical extirpation of caprice and the absolute reliance upon
law in Nature, there grew with the growth of scientific
notions a desire and determination to sweep from the field
oft theory this mob of gods and demons, and to place
natural phenomena on a basis more congruent with themselves.
The problem which had been previously approached
from above was now attacked from below; theoretic effort
passed from the super- to the sub-sensible. It was felt
that to construct the universe in idea it was necessary to
have some notion of its constituent parts-of what Lucretius subsequently called the "First Beginnings." Abstracting again from experience, the leaders of scientific
speculation reached at length the pregnant doctrine of




ADDRESS AT BELFAST.


9


atoms and molecules, the latest developments of which
were set forth with such power and clearness at the last
meeting of the British Association. Thought, no doubt,
had long hovered about this doctrine before it attained
the precision and completeness which it assumed in the
mind of Democritus,' a philosopher who may well for a
moment arrest our attention. "Few great men," says
Lange, a non-materialist, in his excellent "History of
Materialism," to the spirit and to the letter of which I am
equally indebted, "have been so despitefully used by history as Democritus. In the distorted images sent down
to us through unscientific traditions there remains of him
almost nothing but the name of 'the laughing philosopher,' while figures of immeasurably smaller significance
spread themselves out at full length before us." Lange
speaks of Bacon's high appreciation of Democritus-for
ample illustrations of which I am indebted to my excellent
friend Mr. Spedding, the learned editor and biographer of
Bacon.  It is evident, indeed, that Bacon considered
Democritus to be a man of weightier metal than either
Plato or Aristotle, though their philosophy "was noised
and celebrated in the schools, amid the din and pomp of
professors." It was not they, but Genseric and Attila and
the barbarians, who destroyed the atomic philosophy.
"For, at a time when all human learning had suffered shipwreck, these planks of Aristotelian and Platonic philosophy,
as being of a lighter and more inflated substance, were
preserved and came down to us, while things more solid
sank and almost passed into oblivion."
The son of a wealthy father, Democritus devoted the
whole of his inherited fortune to the culture of his mind.
He traveled everywhere; visited Athens when Socrates
and Plato were there, but quitted the city without making
himself known. Indeed, the dialectic strife in which Soc1 Born 460 B. c.................




10


PROFESSOR TYNDALL'S


rates so much delighted had no charms for Democritus,
who held that " the man who readily contradicts and uses
many words is unfit to learn any thing truly right." He
is said to have discovered and educated Protagoras the
sophist, being struck as much by the manner in which he,
being a hewer of wood, tied up his fagots, as by the
sagacity of his conversation. Democritus returned poor
from his travels, was supported by his brother, and at
length wrote his great work entitled " Diakosmos," which
he read publicly before the people of his native town.
He was honored by his countrymen in various ways, and
died serenely at a great age.
The principles enunciated by Democritus reveal his
uncompromising antagonism to those who deduced the
phenomena of Nature from the caprices of the gods. They
are briefly these: 1. From nothing comes nothing.
Nothing that exists can be destroyed. All changes are
due to the combination and separation of molecules. 2.
Nothing happens by chance. Every occurrence has its
cause from which it follows by necessity. 3. The only
existing things are the atoms and empty space; all else
is mere opinion. 4. The atoms are infinite in number and
infinitely various in form; they strike together, and the
lateral motion and whirlings which thus arise are the beginnings of worlds. 5. The varieties of all things depend
upon the varieties of their atoms, in number, size, and aggregation. 6. The soul consists of fine, smooth, round
atoms, like those of fire. These are the most mobile of all.
They interpenetrate the whole body, and in their motions
the phenomena of life arise. The first five propositions
are a fair general statement of the atomic philosophy, as
now held. As regards the sixth, Democritus made his
fine smooth atoms do duty for the nervous system, whose
functions were then unknown. The atoms of Democritus
are individually without sensation; they combine in obedi



ADDRESS AT BELFAST.


11


ence to mechanical laws; and not only organic forms, but
the phenomena of sensation and thought, are the result of
their combination.
That great enigma, "the exquisite adaptation of one
part of an organism to another part, and to the conditions
of life," more especially the construction of the human
body, Democritus made no attempt to solve. Empedocles,
a man of more fiery and poetic nature, introduced the notion of love and hate among the atoms to account for
their combination and separation. Noticing this gap in
the doctrine of Democritus, he struck in with the penetrating thought, linked, however, with some wild speculation, that it lay in the very nature of those combinations
which were suited to their ends (in other words, in harmony with their environment) to maintain themselves, while
unfit combinations, having no proper habitat, must rapidly
disappear. Thus more than two thousand years ago the
doctrine of the " survival of the fittest," which in our day,
not on the basis of vague conjecture, but of positive knowledge, has been raised to such extraordinary significance,
had received at all events partial enunciation.'
Epicurus,' said to be the son of a poor school-master at
Samos, is the next dominant figure in the history of the
atomic philosophy. He mastered the writings of Democritus, heard lectures in Athens, went back to Saros, and
subsequently wandered through various countries. He
finally returned to Athens, where he bought a garden, and
surrounded himself by pupils, in the midst of whom he
lived a pure and serene life, and died a peaceful death.
Democritus looked to the soul as the ennobling part of
man; even beauty without understanding partook of animalism. Epicurus also rated the spirit above the body;
the p!easure of the body was that of the moment, while
the spirit could draw upon the future and the past. His
Lange, second edition, p. 23.  a Born 342 n. c.




12


PROFESSOR TYNDALL'S


philosophy was almost identical with that of Democritus;
but he never quoted either friend or foe. One mai*n object
of Epicurus was to free the world from superstition and
the fear of death. Death he treated with indifference. It
merely robs us of sensation. As long as we are, death is
not; and, when death is, we are not. Life has no more
evil for him who has made up his mind that it is no evil
not to live. He adored the gods, but not in the ordinary
fashion. The idea of divine power, properly purified, he
thought an elevating one. Still he taught, " Not he is
godless who rejects the gods of the crowd, but rather he
who accepts them." The gods were to him eternal and
immortal beings, whose blessedness excluded every thought
of care or occupation of any kind. Nature pursues her
course in accordance with everlasting laws, the gods never
interfering. They haunt
"The lucid interspace of world and world
Where never creeps a cloud or moves a wind,
Nor ever falls the least white star of snow,
Nor ever lowest roll of thunder moans,
Nor sound of human sorrow mounts to mar
Their sacred everlasting calm."'
Lange considers the relation of Epicurus to the gods
subjective; the indication probably of an ethical requirement of his own nature. We cannot read history with
open eyes, or study human nature to its depths, and fail to
discern such a requirement. Man never has been, and
he never will be, satisfied with the operations and products
of the understanding alone; hence physical science cannot cover all the demands of his nature. But the history
of the efforts made to satisfy these demands might be
broadly described as a history of errors-the error, in great
part, consisting in ascribing fixity to that which is fluent,
which varies as we vary, being gross when we are gross,
1 Tennyson's " Lucretius."




ADDRESS AT BELFAST.


13


and becoming, as our capacities widen, more abstract and
sublime. On one great point the mind of Epicurus was
at p ^. He neither sought nor expected, here or hereafter, any personal profit from his relation to the gods.
And it is assuredly a fact that loftiness and serenity of
thought may be promoted by conceptions which involve
no idea of profit of this kind. ' Did I not believe," said
a great man to me once, " that an Intelligence is at the
heart of things, my life on earth would be intolerable."
The utterer of these words is not, in my opinion, rendered less noble but more noble by the fact that it was the
need of ethical harmony here, and not the thought of personal profit hereafter, that prompted his observation.
There are persons, not belonging to the highetL intellectual zone, nor yet to the lowest, to whom perfect clearness of exposition suggests want of depth.  They find
comfort and edification in an abstract and learned phraseology. To some such people Epicurus, who spared no
pains to rid his style of every trace of haze and turbidity,
appeared, on this very account, superficial. HIe had, however, a disciple who thought it no unworthy occupation to
spend his days and nights in the effort to reach the clearness of his master, and to whom the Greek philosopher is
mainly indebted for the extension and perpetuation of his
fame. A century and a half after the death of Epicurus,
Lucretius ' wrote his great poem, "On the Nature of
Things," in which he, a Roman, developed with extraordinary ardor thie philosophy of his Greek predecessor. He
wishes to win over his friend Memnius to the school of
Epicurus; and, although he has no rewards in a future life
to offer, although his object appears to be a purely negative one, he addresses his friend with the heat of an apostle. His object, like that'of his great forerunner, is the
destruction of superstition; and considering that men
1 Born 99 B. c.




14


PROFESSOR TYNDALL'S '


trembled before every natural event as a direct monition
from the gods, and that everlasting torture was also in
prospect, the freedom aimed at by Lucretius might perhaps be deemed a positive good. "This terror," he says,
" and darkness of mind must be dispelled, not by the rays
of the sun and glittering shafts of day, but by the aspect
and the law of Nature." Ile refutes the notion that any
thing can come out of nothing, or that that which is once
begotten can be recalled to nothing. The first beginnings,
the atoms, are indestructible, and into them all things can
be resolved at last. Bodies are partly atoms, and partly
combinations of atoms; but the atoms nothing can quench.
They are strong in solid singleness, and by their denser
combination all things can be closely packed and exhibit
enduring strength,  He denies that matter is infinitely
divisible. We come at length to the atoms, without which,
as an imperishable substratum, all order in the generation
and development of things would be destroyed.
The mechanical shock of the atoms being in his view
the all-sufficient cause of things, he combats the notion
that the constitution of Nature has been in any way determined by intelligent design. The interaction of the
atoms throughout infinite time rendered all manner of
combinations possible.  Of these the 'fit ones persisted,
while the unfit ones disappeared. Not after sage deliberation did the atoms station themselves in their right places,
nor did they bargain what motions they should assume.
From all eternity they have been driven together, and,
after trying motions and unions of every kind, they fell at
length into the arrangements out of which this system of
t!hings has been formed. "'If you will apprehend and
keep in mind these things, Nature, free at once, and rid of
her haughty lords, is seen to do all things spontaneously
of herself, without the meddling of the go(d.^"
1 Monro's translation. In his criticism of this work, Conteimporary




ADDRESS AT BELFAST.


15


l1To meet the objection that his atoms cannot be seen,
Lucretius describes a violent storm, and shows that the
invisible particles of air act in the same way as the visible
particles of water. We perceive, moreover, the different
smells of things, yet never see them coming to our nostrils. Again, clothes hung up on a shore which waves
break upon become moist, and then get dry if spread out
in the sun, though no eye can see either the approach or
the escape of the water-particles. A ring, worn long on
the finger, becomes thinner; a water-drop hollows out a
stone; the ploughshare is rubbed away in the field; the
street-pavement is worn by the feet; but the particles that
disappear at any moment we cannot see. Nature acts
through invisible particles. That Lucretius had a strong
scientific imagination the foregoing references prove. A
fine illustration of his power in this respect is his explanation of the apparent rest of bodies whose atoms are in
motion. He employs the image of a flook of sheep with
skipping lambs, which, seen from a distance, presents
simply a white patch upon the green hill, the jumping of
the individual lambs being quite invisibl,.
His vaguely-grand conception of the atoms falling eternally through space suggested the nebular hypothesis to
Kant, its first propounder. Far beyond the limits of our
visible world are to be found atoms innumerable, which
have never been united to form bodies, or which, if once
united, have been again dispersed, falling silently through
immeasurable intervals of time and space. As everywhere
throughout the All the same conditions are repeated, so
must the phenomena be repeated also. Above us, below
us, beside us, therefore, are worlds without end; and this,
when considered, must dissipate every thought of a deflecReview, 1867, Dr. Hayman does not appear to be aware of the really
sound and subtile observations on which the reasoning of Lucretius,
though erroneous, sometimes rests.




16


PROFESSOR TYNDALL'S


tion of the universe by the gods. The worlds come and go,
attracting new atoms out of limitless space, or dispersing
their own particles. The reputed death of Lucretius, which
forms the basis of Mr. Tennyson's noble poem, is in strict
accordance with his philosophy, which was severe and pure.
During the centuries lying between the first of these
three philosophers and the last, the human intellect was
active in other fields than theirs. The sophists had run
through their career. At Athens had appeared Socrates,
Plato, and Aristotle, who ruined the sophists, and whose
yoke remains to some extent unbroken to the present
hour. Within this period also the School of Alexandria
was founded, Euclid wrote his " Elements," and made some
advance in optics. Archimedes had propounded the theory
of the lever and the principles of hydrostatics. Pythagoras had made his experiments on the harmonic intervals,
while astronomy was immensely enriched by the discoveries
of Hipparchus, who was followed by the historically more
celebrated Ptolemy. Anatomy had been made the basis of
scientific medicine; and it is said by Draper that vivisection then began. In fact, the science of ancient Greece had
already cleared the world of the fantastic images of divinities
operating capriciously through natural phenomena. It had
shaken itself free from that fruitless scrutiny " by the internal light of the mind alone," which had vainly sought
to transcend experience and reach a knowledge of ultimate
causes. Instead of accidental observation, it had introduced observation with a purpose; instruments were employed to aid the senses; and scientific method was
rendered in a great measure complete by the union of Induction and Experiment.
What, then, stopped its victorious advance? Why was
the scientific intellect compelled, like an exhausted soil, to
1" History of the Intellectual Development of Europe," p. 295.


e




ADDRESS AT BELFAST.


17


lie fallow for nearly two millenniums before it could regather the elements necessary to its fertility and strength?
Bacon has already let us know one cause; Whewell ascribes this stationary period to four causes-obscurity of
thought, servility, intolerance of disposition, enthusiasm of
temper-and he gives striking examples of each.1 But
these characteristics must have had their antecedents in
the circumstances of the time. Rome and the other cities
of the empire had fallen into moral putrefaction. Christianity had appeared, offering the gospel to the poor, and, by
moderation if not asceticism of life, practically protesting
against the profligacy of the age. The sufferings of the
early Christians, and the extraordinary exaltation of mind
which enabled them to triumph over the diabolical tortures
to which they were subjected,' must have left traces not
easily effaced. They scorned the earth, in view of that
" building of God, that house not made with hands, eternal
in the heavens." The Scriptures which ministered to their
spiritual needs were also the measure of their science.
When, for example, the celebrated question of antipodes
came to be discussed, the Bible was with many the ultimate
court of appeal. Augustin, who flourished A. D. 400, would
not deny the rotundity of the earth; but he would deny
the possible existence of inhabitants at the other side, "because no such race is recorded in Scripture among the
descendants of Adam." Archbishop Boniface was shocked
at the assumption of a " world of human beings out of the
reach of the means of salvation." Thus reined in, Science
was not likely to make much progress. Later on, the
political and theological strife between the Church and civil
governments, so powerfully depicted by Draper, must have
dlone much to stifle investigation.
Whewell makes many wise and brave remarks regard1 " History of the Inductive Sciences," vol. i.
2 Depicted with terrible vividness in Renan's " Antichrist."




18


PROFESSOR TYNDALL'S


ing the spirit of the middle ages. It was a menial spirit.
The seekers after natural knowledge had forsaken that
fountain of living waters, the direct appeal to Nature by
observation and experiment, and had given themselves up
to the remanipulation of the notions of their predecessors.
It was a time when thought had become abject, and when
the acceptance of mere authority led, as it always does in
science, to intellectual death. Natural events, instead of
being traced to physical, were referred to moral causes;
while an exercise of the fantasy, almost as degrading as
the spiritualism of the present day, took the place of scientific speculation. Then came the mysticism of the middle
ages, magic, alchemy, the Neoplatonic philosophy, with
its visionary though sublime abstractions, which caused men
to look with shame upon their own bodies as hindrances to
the absorption of the creature in the blessedness of the
Creator. Finally came the scholastic philosophy, a fusion,
according to Lange, of the least-mature notions of Aristotle
with the Christianity of the West. Intellectual immobility
was the result. As a traveler without a compass in a fog
may wander long, imagining he is making way, and find
himself after hours of toil at his starting-point, so the
schoolmen, having "tied and untied the same knots and
formed and dissipated the same clouds," found themselves
at the end of centuries in their old position.
With regard to the influence wielded by Aristotle in
the middle ages, and which, though to a less extent, he
still wields, I would ask permission to make one remark.
When the human mind has achieved greatness and given
evidence of extraordinary power in any domain, there is a
tendency to credit it with similar power in all other
domains. Thus theologians have found comfort and assurance in the thought that Newton dealt with the question of revelation, forgetful oi tiue fact that the very devotion of his powers, through all the best years of his life,




ADDRESS AT BELFAST.


19


to a totally different class of ideas, not to speak of any
natural disqualification, tended to render him less instead of
more competent to deal with theological and historic questions. Goethe, starting from his established greatness as a
poet, and indeed from his positive discoveries in natural
history, produced a profound impression among the painters
of Germany when he published his " Farbenlehre," in which
he endeavored to overthrow Newton's theory of colors.
This theory he deemed so obviously absurd that he considered its author a charlatan, and attacked him with a
corresponding vehemence of language. In the domain of
natural history Goethe had made really considerable discoveries; and we have high authority for assuming that,
had he devoted himself wholly to that side of science, he
might have reached in it an eminence comparable with
that which he attained as a poet. In sharpness of observation, in the detection of analogies, however apparently
remote, in the classification and organization of facts according to the analogies discerned, Goethe possessed extraordinary powers. These elements of scientific inquiry
fall in with the discipline of the poet. But, on the other
hand, a mind thus richly endowed in the direction of natural
history may be almost shorn of endowment as regards
the more strictly-called physical and mechanical sciences.
Goethe was in this condition. He could not formulate
distinct mechanical conceptions; he could not see the force
of mechanical reasoning; and in regions where such reasoning reigns supreme he became a mere ignis fatuus to
those who followed him.
I have sometimes permitted myself to compare Aristotle with Goethe, to credit the Stagirite with an almost
superhuman power of amassing and systematizing facts, but
to consider him fatally defective on that side of the mind
in respect to which incompleteness has been just ascribed
to Goethe. Whewell refers the errors of Aristotle, not to




20


PROFESSOR TYNDALL'S


a neglect of facts, but to a " neglect of the idea appropriate
to the facts; the idea of mechanical cause, which is force,
and the substitution of vague or inapplicable noticns, involvilfg only relations of space or emotions of wonder."
This is doubtless true; but the word " neglect " implies mere
intellectual misdirection, whereas in Aristotle, as in Goethe,
it was not, I believe, misdirection, but sheer natural incapacity which lay at the root of his mistakes. As a physicist,
Aristotle displayed what we should consider some of the
worst attributes of a modern physical investigator-indis-.
tinctness, of ideas, confusion of mind, and a confident use of
language, which led to the delusive notion that he had
really mastered his subject, while he had as yet failed to
grasp even the elements of it. He put words in the place
of things, subject in the place of object. He preached induction without practising it, inverting the true order of
inquiry by passing from the general to the particular instead of from the particular to the general. He made of the
universe a closed sphere, in the centre of which he fixed
the earth, proving from general principles, to his own satisfaction and to that of the world for near two thousand years,
that no other universe was possible. His notions of motion
were entirely unphysical. It was natural or unnatural,
better or worse, calm or violent —no real mechanical
conception regarding it lying at the bottom of his mind.
He affirmed that a vacuum could not exist, and proved that
if it did exist motion in it would be impossible. He determined a priori how many species of animals must exist,
and shows on general principles why animals must have
such and such parts. When an eminent contemporary
philosopher, who is far removed from errors of this kind,
remembers these abuses of the a priori method, he will be
able to make allowance for the jealousy of physicists as to
the acceptance of so-called a priori truths. Aristotle's
errors of detail, as shown by Eucken and Lange, were grave


*




ADDRESS AT BELFAST.


21


and numerous. He affirmed that only in man we had the
beating of the heart, that the left side of the body wvas
colder than the right, that men have more teeth than
women, and that there is an empty space at the back of
every man's head.
There is one essential quality in physical conceptions
which is entirely wanting in those of Aristotle and his followers. I wish it could be expressed by a word untainted
by its associations; it signifies a capability of being placed
as a coherent picture before the mind. The Germans express the act of picturing by the word vorstellen, and the
picture they call a Vorstellung. We have no word in English which comes nearer to our requirements than imayination, and, taken with its proper limitations, the word
answers very well; but, as just intimated, it is tainted
by its associations, and therefore objectionable to some
minds. Compare, with reference to this capacity of mental presentation, the case of the Aristotelian who refers
the ascent of water ill a pump to Nature's abhorrence of a
vacuum, with that of Pascal when he proposed to solve the
question of atmospheric pressure by the ascent of the
Puy de D~me. In the one case the terms of the explanation refuse to fall into place as a physical image; in the
other the image is distinct, the fall and rise of the barometer being clearly figured as the balancing of two varying
and opposing pressures.
During the drought of the middle ages in Christendom, the Arabian intellect, as forcibly shown by Draper,
was active. With the intrusion of the Moors into Spain,
he says, order, learning, and refinement, took the place of
their opposites. When smitten with disease, the Christian
peasant resorted to a shrine, the Moorish one to an instructed physician.  The Arabs encouraged translations
from the Greek philosophers, but not from the Greek poets.
They turned in disgust " from the lewdness of our classical




22


PROFESSOR TYNDALL'S


mythology, and denounced as an unpardonable blasphemy
all connection between the impure Olympian Jove and the
Most High God;" Draper traces still further than Whewell the Arab elements in our scientific terms, and points
out that the under-garment of ladies retains to this hour
its Arab name. He gives examples of what Arabian men
of science accomplished, dwelling particularly on Alhazan,
who was the first to correct the Platonic notion that rays
of light are emitted by the eye. He discovered atmospheric refraction, and points out that we see the sun and
the moon after they have set. He explains the enlargement of the sun and moon, and the shortening of the vertical diameters of both these bodies, when near the horizon.
He is aware that the atmosphere decreases in density with
increase of elevation, and actually fixes its height at fiftyeight and a half miles. In the " Book of the Balance Wisdom," he sets forth the connection between the weight of
the atmosphere and its increasing density. He shows that
a body will weigh differently in a rare and dense atmosphere; he considers the force with which plunged bodies
rise through heavier media. He understands the doctrine
of the centre of gravity, and applies it to the investigation
of balances and steelyards. He recognizes gravity as a
force, though he falls into the error of making it diminish
simply as the distance increased, and of making it purely
terrestrial. He knows the relation between the velocities,
spaces, and times of falling bodies, and has distinct ideas
of capillary attraction. He improved the hydrometer. The
determination of the densities of bodies as given by Alhazan
approaches very closely to our own. " I join," says Draper,
" in the pious prayer of Alhazan, 'that in the day of judgment the All-Merciful will take pity on the soul of AburRaihan, because he was the first of the race of men to construct a table of specific gravities." If all this be historic
truth (and I have entire confidence in Dr. Draper), well may




ADDRESS AT BELFAST.


23


he " deplore the systematic manner in which the literature
of Europe has contrived to put out of sight our scientific
obligations to the Mohammedans." 1
The strain upon the mind during the stationary period
toward ultra-terrestrial things, to the neglect of problems
close at hand, was sure to provoke reaction. But the reaction was gradual; for the ground was dangerous, a power
being -at hand competent to crush the critic who went too
far. To elude this power and still allow opportunity for the
expression of opinion, the doctrine of " twofold truth " was
invented, according to which an opinion might be held " theologically" and the opposite opinion "philosophically."'
Thus in the thirteenth century the creation of the world in
six days, and the unchangeableness of the individual soul,
which had been so distinctly affirmed by St. Thomas
Aquinas, were both denied philosophically, but admitted
to be true as articles of the Catholic faith. When Protagoras uttered the maxim which brought upon him so much
vituperation, that " opposite assertions are equally true," he
sinliply i meant that human beings differed so much from each
other that what was subjectively true to the one might be
subjectively untrue to the other. The great sophist never
meant to play fast and loose with the truth by saying that
one of two opposite assertions, made by the same individual, could possibly escape being a lie. It was not "sophistry," but the dread of theologic vengeance, that generated
this double dealing with conviction; and it is astonishing
to notice what lengths were possible to men who were
adroit in the use of artifices of this kind.
Toward the close of the stationary period a word-weariness, if I may so express it, took more and more possession
of men's minds. Christendom had become sick of the
school philosophy and its verbal wastes, which led to no
1" Intellectual Development of Europe," p. 359.
2Lange, second edition, pp. 181, 182.




24


PROFESSOR TYNDALL'S


issue, but left the intellect in everlasting haze. Here and
there he heard the voice of one impatiently crying in the
wilderness4'tNot unto Aristotle, not unto subtile hypothesis, not unto Church, Bible, or blind tradition, must we turn
for a knowledge of the universe, but to the direct investigation of Nature by observation and experiment." In
1543 the epoch-making work of Copernicus on the paths
of the heavenly bcdies appeared. The total crash of Aristotle's closed universe with the earth at its centre followed
as a consequence, and " the earth moves!" became a kind
of watchword among intellectual freemen. Copernicus
was canon of the Church of Frauenburg, in the diocese of
Ermeland. For three-and-thirty years he had withdrawn
himself from the world and devoted himself to the consolidation of his great scheme of the solar system. He made
its blocks eternal; and even to those who feared it and desired its overthrow it was so obviously strong that they refrained for a time from meddling with it. In the last year
of the life of Copernicus his book appeared: it is said that
the old man received a copy of it a few days before his
death, and then departed in peace.
The Italian philosopher, Giordano Bruno, was one cf
the earliest converts to the new astronomy. Taking Lucretius as his exemplar, be revived the notion of the infinity
of worlds; and, combining. with it the doctrine of Copernicus, reached the sublime generalization that the fixed
stars are suns, scattered numberless through space and accompanied by satellites, which bear the same relation to
them that our earth does to our sun, or our moon to our
earth. This was an expansion of transcendent import; but
Bruno came closer than this to our present line of thought.
Struck with the problem of the generation and maintenance
of organisms, and duly pondering it, he came to the conclusion that Nature in her productions does not imitate the
technic of man. Her process is one of unraveling and un



ADDRESS AT BELFAST.


25


folding. The infinity of forms under which matter appears
was not imposed upon it by an external artificer; by its
o\-wn intrinsic force and virtue it brings these forms forth.
AMatter is not the mere naked, empty capacity which philosophers have pictured her to be, but the universal mother
who brings forth all things as the fruit of her own womb.
This outspoken man was originally a Dominican monk.
He was accused of heresy and had to fly, seeking refuge in
Geneva, Paris, England, and Germany. In 1592 he fell
into the hands of the Inquisition at Venice. Hie was imprisoned for many years, tried, degraded, excommunicated,
and handed over to the civil power, with the request that
he should be treated gently and "without the shedding of
blood." This meant that he was to be burnt; and burnt
accordingly he was, on the 16th of February, 1600. To
escape a similar fate, Galileo, thirty-three years afterward, abjured, upon his knees, and with his hands upon the
holy gospels, the heliocentric doctrine which he knew to be
true. After Galileo came Kepler, who from his German
home defied the power beyond the Alps. He traced out
from preexisting observations the laws of planetary motion.
Materials were thus prepared for Newton, who bound thdse
empirical laws together by the principle of gravitation.
In the seventeenth century Bacon and Descartes, the
restorers of philosophy, appeared in succession. Differently
educated and endowed, their philosophic tendencies were
different. Bacon held fast to Induction, believing firmly in
the existence of an external world, and making collected
experiences the basis of all knowledge. The mathematical
studies of Descartes gave him a bias toward Deduction;
and his fundamental principle was much the same as that
of Protagoras, who made the individual man the measure
of all things. "I think, therefore I am," said Descartes.
Only his own identity was sure to him; and the development of this system would have led to an idealism in which
2




26


PROFESSOR TYNDALL'S


the outer world would be resolved into a mere phenomenon
of consciousness. Gassendi, one of Descartes's contemporaries, of whom we shall hear more presently, quickly pointed
out that the fact of personal existence would be proved as
well by reference to any other act as to the act of thinking.
I eat, therefore I am; or, I love, therefore I am, would be
quite as conclusive. Lichtenberg showed that the very
thing to be proved was inevitably postulated in the first
two words, " I think;" and that no inference from the postulate could by any possibility be stronger than the postulate itself.
But Descartes deviated strangely from the idealism implied in his fundamental principle. He was the first to
reduce, in a manner eminently capable of bearing the test
of mental presentation, vital phenomena to purely mechanical principles. Through fear or love, Descartes was a good
churchman; he accordingly rejects the notion of an atom,
because it was absurd to suppose that God, if he so pleased,
could not divide an atom; he puts in the place of the atoms
small round particles and light splinters, out of which he
builds the organism. He sketches with marvelous physical
insight a machine, with water for its motive power, which
shall illustrate vital actions. He has made clear to his
mind that such a machine would be competent to carry on
the processes of digestion, nutrition, growth, respiration,
and the beating of the heart. It would be competent to
accept impressions from the external sense, to store them
up in imagination and memory, to go through the internal
movements of the appetites and passions, the external
movement of limbs. He deduces these functions of his
machine from the mere arrangement of its organs, as the
movement of a clock or other automaton is deduced from
its weights and wheels. "As far as these functions are
concerned," he says, " it is not necessary to conceive any
other vegetative or sensitive soul, nor any other principle of




ADDRESS AT BELFAST.


27


motion or of life, than the blood and the spirits agitated by
the fire which burns continually in the heart, and which is
in no wise different from the fires which exist in inanimate
bodies." Had Descartes been acquainted with the steamengine, he would have taken it, instead of a fall of water,
as his motive power, and shown the perfect analogy which
exists between the oxidation of the food in the body and
that of the coal in the furnace. He would assuredly have
anticipated Mayer in calling the blood which the heart diffuses " the oil of the lamp of life; " deducing all animal
motions from the combustion of this oil, as the motions
of a steam-engine are deduced from the combustion of
its coal. As the matter stands, however, and considering
the circumstances of the time, the boldness, clearness,
and precision with which he grasped the problem of vital
dynamics constitute a marvelous illustration of intellectual
power.1
During the middle ages the doctrine of atoms had to
all appearance vanished from discussion. In all probability
it held its ground among sober-minded and thoughtful men,
though neither the Church nor the world was prepared to
hear of it with tolerance. Once, in the year 1348, it received distinct expression. But retractation by compulsion
immediately followed, and, thus discouraged, it slumbered
till the seventeenth century, when it was revived by a contemporary and friend of Hobbes and Malmesbury, the orthodox Catholic provost of Digne, Gassendi. But, before stating his relation to the Epicurean doctrine, it will be well
to say a few words on the effect, as regards science, of the
general introduction of monotheism among European nations.
"Were men," says Hume, " led into the apprehension
of invisible intelligent power by contemplation of the
1 See Huxley's admirable essay on Descartes, " Lay Sermons," pp. 364,
365.




28


PROFESSOR TYNDALL'S


works of Nature, they could never possibly entertain any
conception but of one single being, who bestowed existence and order on this vast machine, and adjusted all its
parts to one regular system." Referring to the condition
of the heathen, who sees a god behind every natural event,
thus peopling the world with thousands of beings whose
caprices are incalculable, Lange shows the impossibility of
any compromise between such notions and those of science,
which proceeds on the assumption of never-changing law
and causality. "But," he continues, with characteristic
penetration, " when the great thought of one God, acting
as a unit upon the universe, has been seized, the connection of things in accordance with the law of cause and
effect is not only thinkable, but it is a necessary consequence of the assumption. For when I see ten thousand
wheels in motion, and know, or believe, that they are all
driven by one, then I know that I have before me a
mechanism the action of every part of which is determined
by the plan of the whole. So much being assumed, it
follows that I may investigate the structure of that machine, and the various motions of its parts. For the time
being, therefore, this conception renders scientific action
free." In other words, were a capricious God at the circumference of every wheel and at the end of every lever,
the action of the machine would be incalculable by the
methods of science. But the action of all its parts being
rigidly determined by their connections and relations,
and these being brought into play by a single self-acting
driving-wheel, then, though this last prime mover may
elude me, I am still able to comprehend the machinery
which it sets in motion. We have here a conception of
the relation of Nature to its Author which seems perfectly
acceptable to some minds, but perfectly intolerable to
others. Newton and Boyle lived and worked happily
under the influence of this conception; Goethe rejected it




ADDRESS AT BELFAST.


29


with vehemence, and the same repugnance to accepting it
is manifest in Carlyle.'
The analytic alnd synthetic tendencies of the human
mind exhibit themselves throughout history, great writers
ranging themselves sometimes on the one side, sometimes
on the other. Men of warm feelings and minds open to the
elevating impressions produced by Nature as a whole, whose
satisfaction, therefore, is rather ethical than logical, lean
to the synthetic side; while the analytic harmonizes best
with the more precise and more mechanical bias which
seeks the satisfaction of the understanding. Some form
of pantheism was usually adopted by the one, while a detached Creator, working more or less after the manner of
men, was often assumed by the other. Gassendi is hardly
to be ranked with either. Having formally acknowledged
God as the great first cause, he immediately dropped the
idea, applied the known laws of mechanics to the atons,
deducing thence all vital phenomena. He defended Epicurus, and dwelt upon his purity, both of doctrine and of
life. True he was a heathen, but so was Aristotle. He
assailed superstition and religion, and rightly, because he
did not know the true religion. He thought that the gods
neither rewarded nor punished, and adored them purely in
consequence of their completeness; here we see, says
Gassendi, the reverence of the child instead of the fear of
the slave. The errors of Epicurus shall be corrected, the
body of his truth retained; and then Gassendi proceeds,
as any heathen might do, to build up the world, and all
that therein is, of atoms and molecules. God, who created
earth and water, plants and animals, produced in the first
1 Boyle's model of the universe was the Strasbourg clock with an outside artificer. Goethe, on the other hand, sang" Ihm ziemt's die Welt im Innern zu bewegen,
Natur in sich, sich in Natur zu hegen."
See also Carlyle, "Past and Present," chapter v.




30


PROFESSOR TYNDALL'S


place a definite number of atoms, which constituted the
seed of all things. Then began that series of combinations and decompositions which goes on at present, and
which will continue in future. The principle of every
change resides in matter. In artificial productions the
moving principle is different from the material worked
upon; but in Nature the agent works within, being the
most active and mobile part of the material itself. Thus,
this bold ecclesiastic, without incurring the censure of the
Church or the world, contrives to outstrip Mr. Darwin.
The same cast of mind which caused him to detach the
Creator from his universe led him also to detach the soul
from the body, though to the body he ascribes an influence so large as to render the soul almost unnecessary.
The aberrations of reason were in his view an affair of the
material brain. Mental disease is brain-disease; but then
the immortal reason sits apart, and cannot be touched by
the disease. The errors of madness are efrrors of the instrument, not of the performer.
It may be more than a mere result of education, connecting itself probably with the deeper mental structure
of the two men, that the idea of Gassendi above enunciated
is substantially the same as that expressed by Prof.
Clerk Maxwell at the close of the very able lecture delivered by him at Bradford last year. According to both
philosophers, the atoms, if I understand aright, are the
prepared materials which, formed by the skill of the highest, produce by their subsequent interaction all the phenomena of the material world. There seems to be this
difference, however, between Gassendi and Maxwell: the
one postulates, the other infers his first cause. In his
"manufactured articles," as he calls the atoms, Prof. Maxwell finds the basis of an induction which enables him to
scale philosophic heights considered inaccessible by Kant,
and to take the logical step from the atoms to their Maker.




ADDRESS AT BELFAST.


31


Accepting here the leadership of Kant, I doubt the
legitimacy of Maxwell's logic; but it is impossible not to
feel the ethic glow with which his lecture concludes.
There is, moreover, a very noble strain of eloquence in his
description of the steadfastness of the atoms: "Natural
causes, as we know, are at work, which tend to modify, if
they do not at length destroy, all the arrangements and
dimensions of the earth and the whole solar system. But
though in the course of ages catastrophes have occurred
and may yet occur in the heavens, though ancient systems
may be dissolved and new systems evolved out of their
ruins, the molecules out of which these systems are builtthe foundation-stones of the material universe-remain unbroken and unworn."
The atomic doctrine, in whole or in part, was entertained by Bacon, Descartes, Hobbes, Locke, Newton, Boyle,
and their successors, until the chemical law of multiple
proportions enabled Dalton to confer upon it an entirely
new significance. In our day there are secessions from the
theory, but it still stands firm. Loschmidt, Stoney, and
Sir William Thomson, have sought to determine the sizes
of the atoms, or, rather, to fix the limits between which
their sizes lie; while only last year the discourses of
Williamson and Maxwell illustrate the present hold of the
doctriae upon the foremost scientific minds. In fact, it
may be doubted whether, wanting this fundamental conception, a theory of the material universe is capable of
scientific statement.
Ninety years subsequent to Gassendi the doctrine of
bodily instruments, as it may be called, assumed immense
importance in the hands of Bishop Butler, who, in his
famous " Analogy of Religion," developed, from his own
point of view, and with consummate sagacity, a similar
idea. The bishop still influences superior minds; and it




32


PROFESSOR TYNDALL'S


will repay us to dwell for a moment on his views. He
draws the sharpest distinction between our real selves and
our bodily instruments. He does not, as far as I remember, use the word soul, possibly because the term was so
hackneyed in his day as it had been for many generations
previously. But-he speaks of " living powers," "perceiving" or "percipient powers," " moving agents," "ourselves," in the same sense as we should employ the term soul.
He dwells upon the fact that limbs may be removed, and
mortal diseases assail the body, the mind, almost up to
the moment of death, remaining clear. He refers to
sleep and to swoon, where the " living powers" are suspended, but not destroyed. Hle considers it quite as easy
to conceive of existence out of our bodies as in them:
that we may animate a succession of bodies, the dissolution of all of them having no more tendency to dissolve
our real selves, or " deprive us of living faculties-the
faculties of perception and action-than the dissolution of
any foreign matter which we are capable of receiving
impressions from, or making use of for the common occasi:eis of life."  This is the key of the bishop's position;
i" our organized bodies are no more a part of ourselves
than any other matter around us." In proof of this he
calls attention to the use of glasses, which "prepare objects4' for the " percipient power " exactly as the eye does.
The eye itself is no more percipient than the glass; is
quite as much the instrument of the true self, and also as
foreign to the true self, as the glass is. "And if we see
with our eyes only in the same manner as we do with
glasses, the like may justly be concluded from analogy of
all our senses."
Lucretius, as you are aware, reached a precisely opposite conclusion; and it certainly would be interesting,
if not profitable, to us all, to hear what he would or could
urge in opposition to the reasoning of the bishop. As a




ADDRESS AT BELFAST.


33


brief discussion of the point will enable us to see the
bearings of an important question, I will here permit a
disciple of Lucretius to try the strength of the bishop's
position, and then allow the bishop to retaliate, with the
view of rolling back, if he can, the difficulty upon Lucretius.
The argument might proceed in this fashion:
"Subjected to the test of mental presentation ( Vorstellung), your views, most honored prelate, would present
to miany minds a great, if not an insuperable, difficulty.
-You speak of 'living powers,' 'percipient or perceiving
powers,' and 'ourselves;' but can you form a mental
picture of any one of these apart from the organism
through which it is supposed to act?  Test yourself
honestly, and see whether you possess any faculty that
would enable you to form such a conception. The true
self has a local habitation in each of us; thus localized,
must it not possess a form? If so, what form? Have
you ever for a moment realized it? When a leg is amputated the body is divided into two parts; is the true self
in both of them or in one? Thomas Aquinas might say in
both; but not you, for you appeal to the consciousness
associated with one of the two parts to prove that the
other is foreign matter. Is consciousness, then, a necessary element of the true self? If so, What do you say to
the case of the whole body being deprived of consciousness? If not, then on what grounds do you deny any
portion of the true self to the severed limb? It seems
very singular that, from the beginning to the end of your
admirable book (and no one admires its sober strength
more than I do), you never once mention the brain or
nervous system. You begin at one end of the body, and
show that is parts may be removed without prejudice to
the perceiving power. What if you begin at the other
end, and remove, instead of the leg, the brain? The




34


PROFESSOR TYNDALL'S


body, as before, is divided into two parts; but both are
now in the same predicament, and neither can be appealed
to to prove that the other is foreign matter. Or, instead
of going so far as to remove the brain itself, let a certain
portion of its bony covering be removed, and let a
rhythmic series of pressures and relaxations of pressure
be applied to the soft substance. At every pressure 'the
faculties of perception and of action' vanish; at every
relaxation of pressure they are restored. Where, during
the intervals of pressure, is the perceiving power? I
once had the discharge of a large Leyden battery passed
unexpectedly through me: I felt nothing, but was simply
blotted out of conscious existence for a sensible interval.
Where was my true self during that interval? Men who
have recovered from lightning-stroke have been much
longer in the same state; and, indeed, in cases of ordinary
concussion of the brain, days may elapse during which no
experience is registered in consciousness. Where is the
man himself during the period of insensibility? You
may say that I beg the question when I assume the man
to have been unconscious, that he was really conscious all
the time, and has simply forgotten what had occurred to
him. In reply to this, I can only say that no one need
shrink from the worst tortures that superstition ever lnvented if only so felt and so remembered. I do not think
your theory of instruments goes at all to the bottom of
the matter. A telegraph-operator has his instruments, by
means of which he converses with the world; our bodies
possess a nervous system, which plays a similar part between the perceiving power and external things. Cut theQ
wires of the operator, break his battery, demagnetize his
needle: by this means you certainly sever his connection
with the world; but, inasmuch as these ari real instruments, their destruction does not touch the man who uses
them. The operator survives, and he knows that he sur



ADDRESS AT BELFAST.


36


vives. What is it, I would ask, in the human system that
answers to this conscious survival of the operator when
the battery of the brain is so disturbed as to produce
insensibility, or when it is destroyed altogether?
"Another consideration, which you may consider
slight, presses upon me with some force. The brain may
change from health to disease, and through such a change
the most exemplary man may be converted into a debauchee or a murderer. My very noble and approved good
master had, as you know, threatenings of lewdness intro —
duced into his brain by his jealous wife's philter; and,
sooner than permit himself to run even the risk of yielding
to these base promptings, he slew himself. How could
the hand of Lucretius have been thus turned against himself if the real Lucretius remained as before? Can the
brain or can it not act in this distempered way without
the intervention of the immortal reason? If it can, then
it is a prime mover which requires only healthy regulation
to render it reasonably self-acting, and there is no apparent
need of your immortal reason at all. If it cannot, then
the immortal reason, by its mischievous activity in operating upon a broken instrument, must have the credit i'.
committing every imaginable extravagance and crime. I
think, if you will allow me to say so, that the gravest consequences are likely to flow from your estimate of the
body. To regard the brain as you would a staff or an eyeglass-to shut your eyes to all its mystery, to the perfect
correlation of its condition and our consciousness, to the
fact that a slight excess or defect of blood in it produces
the very swoon to which you refer, and that in relation to
it our meat and drink and air and exercise have a perfectly transcendental value and significance-to forget all
this, does, I think, open a way to innumerable errors in our
habits of life, and may possibly in some cases initiate and
foster that very disease, and consequent mental ruin,




PROFESSOR TYNDALL'S


which a wiser appreciation of this mysterious organ would
have avoided."
I can imagine the bishop thoughtful after hearing this
argument. He was not the man to allow anger to mingle
with the consideration of a point of this kind. After due
reflection, and having strengthened himself by that honest
contemplation of the facts which was habitual with him,
and which includes the desire to give even adverse facts
their due weight, I can suppose the bishop to proceed
thus: "You will remember that in the ' Analogy of Religion,' of which you have so kindly spoken, I did not
profess to prove any thing absolutely, and that I over and
over again acknowledged and insisted on the smallness of
our knowledge, or rather the depth of our ignorance, as
regards the whole system of the universe. My object was
to show my deistical friends, who set forth so eloquently
the beauty and beneficence of Nature and the Ruler thereof,
while they had nothing but scorn for the so-called absurdities of the Christian scheme, that they were in no better
condition than we were, and that, for every difficulty found
upon our side, quite as great a difficulty was to be found
upon theirs. I will now, w "1 your permission, adopt a
similar line of argument. You are a Lucretian, and from
the combination and separation of insensate atoms deduce
all terrestrial things, including organic forms and their
phenomena. Let me tell you, in the first instance, how far
I am prepared to go with you. I admit that you can build
crystalline forms out of this play of molecular force; that
the diamond, amethyst, and snow-star, are truly wonderful
structures which are thus produced. I will go further and
acknowledge that even a tree or flower might in this way
be organized. Nay, if you can show nme an animal without
sensation, I will concede to you that it also might be put
together by the suitable play of molecular force.
" Thus far our way is clear; but now comes my diffi



ADDRESS AT BELFAST.


37


culty. i our atoms are individually without sensation,
much more are they without intelligence. Maly I ask you,
then, to try your hand upon this problem? Take your dead
hydrogen-atoms, your dead oxygen-atoms, your dead carbon-atoms, your dead nitrogen-atoms, your dead phosphorusatoms, and all the other atoms, dead as grains of shot, of
which the brain is formed. Imagine them separate and
sensationless, observe them running together and forming
all imaginable combinations. This, as a purely mechanical
process, is seeable by the mind. But can you see, or dream,
or in any way imagine, how out of that mechanical act, and
from these individually dead atoms, sensation, thought, and
emotion, are to arise? Are you likely to extract Homer out
of the rattling of dice, or the Differential Calculus out of
the clash of billiard-balls? I am not all bereft of this Vorstellungskraft of which you speak, nor am I, like so many
of my brethren,'a mere vacuum as regards scientific knowledge. I can follow a particle of musk until it reaches the
olfactory nerve; I can follow the waves of sound until their
tremors reach the water of the labyrinth and set the otoliths
and Corti's fibres in motion; I can also visualize the waves
of ether as they cross the eye and hit the retina. Nay,
more, I am able to pursue to the central organ the motion
thus imparted at the periphery, and to see in idea the very
molecules of the brain thrown into tremors. My insight is
not baffled by these physical processes.  What baffles
and bewilders me, is the notion that from those physical
tremors things so utterly incongruous with tlhm as sensation, thought, and emotion, can be derived. You may say,
or think,, that this issue of consciousness from the clash of
atoms is not more incongruous than the flash of light from
the union of oxygen and hydrogen. But I beg to say that
it is. For such incongruity as the flash possesses is that
s l ich I now force upon your attention. The flash is an
affair of consciousness, the objective counterpart of which




88


PROFESSOR TYNDALL'S


is a vibration. it is a flash only by your interpretation.
You are the cause of the apparent incongruity, and you
are the thing that puzzles me. I need not remind you that
the great Leibnitz felt the difficulty which I feel, and that
to get rid of this monstrous deduction of life from death
he displaced your atoms by his monads, which were more
or less perfect mirrors of the universe, and out of the summation and integration of which he supposed all the phenomena of life-sentient, intellectual, and emotional-to
arise..           I
"Your difficulty, then, a~s ] see you are ready to admit,
is quite as great as mine. *You cannot satisfy the human
understanding in its demand for logical continuity between
molecular processes and the phenomrena of consciousness.
This is a rock on which materialism must inevitably split
whenever it pretends to beac~pmptete philosophy of life.
What is the moral, my Luceetian? You and I are not
likely to indulge in ill-temper in the discussion of these
great topics, where we see so much room for honest differences of opinion. But there are people of less wit or more
bigotry (I say it with humility) on both sides, who are ever
ready to mingle anger and vituperation with such discussions. There are, for example, writers of note and influence at the present day who are not ashamed to assume
the 'deep personal sin' of a great logician to be the cause
of his unbelief in a theologic dogma. And there are others
who hold that we, who cherish our noble Bible, wrought as
it has been into the constitution of our forefathers, and by
inheritance into us, must necessarily be hypocritical and
insincere. Let us disavow and discountenance such people,
cherishing the unswerving faith that what is good and true
in both our arguments will be preserved for the benefit of
humanity, while all that is bad or false will disappenar."
I hold the bishop's reasoning to be unanswerable, and
his liberality to be worthy of imitation.




ADDRESS AT BELFAST.


39


It is worth remarking that in one respect the bishop
was a product of his age. Long previous to his day the
nature of the soul had been so favorite and general a topic
of discussion, that, when the students of the University of
Paris wished to know the leanings of a new professor, they
at once requested him to lecture upon the soul. About
the time of Bishop Butler the question was not only agitated, but extended. It was seen by the clear-witted men
who entered this arena that many of their best arguments
applied equally to brutes and men. The bishop's arguments were of this character. He saw it, admitted it,
accepted the consequences, and boldly embraced the whole
animal world in his scheme of immortality.
Bishop Butler accepted with unIwavering trust the
chronology of the Old Testament, describing it as "confirmed by the natural and civil history of the world, collected from common historians, from the state of the earth,
and from the late inventions of arts and sciences." These
words mark progress; and they must seem somewhat hoary
to the bishop's successors of to-dayl.  It is hardly necessary to inform you that since his time the domain of the
naturalist has been immensely extended-the whole science
of geology, with its astounding revelations regarding the
life of the ancient earth, having been created. The rigidity
of old conceptions has been relaxed, the public mind being
rendered gradually tolerant of the idea that not for six thousand, nor for sixty thousand, nor for six thousand thousand
thousand, but for aeons embracing untold millions of years,
this earth has been the theatre of life and death. The riddle of the rocks has been read by the geologist and paleontologist, from the subcambrian depths to the deposits thickening over the sea-bottoms of to-day. And upon the leaves
Only to some; for there are dignitaries who even now speak of the
earth's rocky crust as so much building-material prepared for man at the
Creation. Surely it is time that this loose language should cease.




40


PROFESSOR TYNDALL'S


of that stone book are, as you know, stamped the characters, plainer and surer than those formed by the ink of history, which carry the mind back into abysses of past time
compared with which the periods which satisfied Bishop
Butler cease to have a visual angle.
The lode of discovery once struck, those petrified forms
in which life was at one time active increased to multitudes
and demanded classification. They were grouped in genera,
species, and varieties, according to the degree of similarity
subsisting between them. Thus confusion was avoided,
each object being found in the pigeon-hole appropriated to
it and to its fellows of similar morphological or physiological character. The general fact soon became evident that
none but the simplest forms of life lie lowest down, that, as
we climb higher among the superimposed strata, more perfect forms appear. The change, however, from form to
form, was not continuous, but by steps-some small, some
great. "A section," says Mr. Huxley, "a hundred feet
thick will exhibit at different heights a dozen species of
ammonite, none of which passes beyond its particular zone
of limestone, of clay, into the zone below it, or into that
above it.' In the presence of such facts it was not possible to avoid the question: Have these forms, showing,
though in broken stages and with many irregularities, this
unmistakable general advance, been subjected to no continuous law of growth or variation? Had our.education been
purely scientific, or had it been sufficiently detached from
influences which, however ennobling in another domain,
have always proved hinderances and delusions when introduced as factors into the domain of physics, the scientific
mind never could have swerved from the search for a law
of growth, or allowed itself to accept the anthropomorphism which regarded each successive stratum as a kind of
mechanic's bench for the manufacture of new species out of
all relation to the old.




ADDRESS AT BELFAST.


41


Biased, however, by their previous education, the
great majority of naturalists invoked a special creative act
to account for the appearance of each new group of organisms.  Doubtless there were numbers who were clearheaded enough to see that this was no explanation at all;
that in point of fact it was an attempt, by the introduction
of a greater difficulty, to account for a less. But, having
nothing to offer in the way of explanation, they for the most
part held their peace. Still the thoughts of reflecting men
naturailly and necessarily simmered round the question.
De Maillet, a contemporary of Newton, has been brought
into notice by Prof. Huxley as one who " had a notion of
the modifiability of living forms." In my frequent conversations with him, the late Sir Benjamin Brodie, a man of
highly-philosophic mind, often drew my attention to the
fact that, as early as 1794, Charles Dtrwin's grandfather
was the pioneer of Charles Darwin.' In 1801, and in subsequent years, the celebrated Lamarck, who produced so
profound an impression on the public mind through the
vigorous exposition of his views by the author of the " Vestiges of Creation," endeavored to show the development
of species out of changes of habit and external condition.
In 1813 Dr. Wells, the founder of our present theory of
dew, read before the Royal Society a paper in which, to
use the words of Mr. Darwin, "he distinctly recognizes
the principle of natural selection; and this is the first recognition that has been indicated." The thoroughness and
skill with which Wells pursued his work, and the obvious
independence of his character, rendered him long ago a
favorite with me; and it gave me the liveliest pleasure to
aliflht upon this additional testimony to his penetration.
i,,f. Grant, Mr. Patrick Matthew, Von Buch, the author
of the " Vestiges," D'Halloy, and others,' by the enuncia1 "Zoonomia" vol. i., pp. 500-510.
2 In 1855 Mr. Herbert Spencer (" Principles of Psychology," second




42


PROFESSOR TYNDALL'S


tion of opinions more or less clear and correct, showed that
the question had been fermenting long prior to the year
1858, when Mr. Darwin and Mr. Wallace simultaneously,
but independently, placed their closely concurrent views
upon the subject before the Linnsean Society.
These papers were followed in 1859 by the publication
of the first edition of " The Origin of Species." All great
things come slowly to the birth. Copernicus, as I informed
you, pondered his great work for thirty-three years. Newton for nearly twenty years kept the idea of gravitation
before his mind; for twenty years also he dwelt upon his
discovery of fluxions, and doubtless would have continued
to make it the object of his private thought had he not
found that Leibnitz was upon his track. Darwin for twoand-twenty years pondered the problem of the origin of
species, and doubtless be would have continued to do so
had he not found Wallace upon his track.' A concentrated
but full and powerful epitome of his labors was the consequence. The book was by no means an easy one; and
probably not one in every score of those who then attacked
it had read its pages through, or were competent to grasp
their significance if they had. I do not say this merely to discredit them; for there were in those days some
really eminent scientific men, entirely raised above the
heat of popular prejudice, willing to accept any conclusion
that science had to offer, provided it was duly backed by
fact and argument, and who entirely mistook Mr. Darwin's
views. In fact, the work needed an expounder; and it
found one in Mr. Huxley. I know nothing more admirable
in the way of scientific exposition than those early articles
edition, vol. i., p. 465) expressed " the belief that life under all its forms
has arisen by an unbroken evolution, and through the instrumentality of
what are called natural causes."
1 The behavior of Mr. Wallace in relation to thiss subject has been
dignified in the highest degree.




ADDRESS AT BELFAST.


43


of his on the origin of species. He swept the curve of discussion through the really significant points of the subject,
enriched his exposition with profound original remarks and
reflections, often summing up in a single pithy sentence an
argument which a less compact mind would have spread
over pages. But there is an impression made by the book
itself which no exposition of it, however luminous, can convey; and that is the impression of the vast amount of labor, both of observation and of thodght, implied in its production. Let us glance at its principles.
It is conceded on all hands that what are called varieties are continually produced. The rule is probably without exception. No chick and no child is in all respects
and particulars the counterpart of its brother and sister;
and in such differences we have " variety " incipient. No
naturalist could tell how far this variation could be carried;
but the great mass of them held that never by any amount
of internal or external change, nor by the mixture of both,
could the offspring of the same progenitor so far deviate
from each other as to constitute different species. The
function of the experimental philosopher is to combine the
conditions of Nature and to produce her results; and this
was the method of'Darwin.' He made himself acquainted
with what could, without any manner of doubt, be done in
the way of producing variation. He associated himself
with pigeon-fanciers-bought, begged, kept, and observed
every breed that he could obtain. Though derived from a
common stock, the diversities of these pigeons were such
that " a score of them might be chosen which, if shown to
an ornithologist, and he were told that they were wild
birds, would certainly be ranked by. him as well-defined
1 The first step only toward experimental demonstration has been
taken. Experiments now begun might, a couple of centuries hence,
furnish data of incalculable value, which ought to be supplied to the
science of the future.




44


PROFESSOR TYNDALL'S


species." The simple principle which guides the pigeonfancier, as it does the cattle-breeder, is the selection of
some variety that strikes his fancy, and the propagation
of this variety by inheritance. With his eye still directed
to the particular appearance which he wishes to exaggerate, he selects it as it reappears in successive broods, and
thus adds increment to increment until an astonishing
amount of divergence from the parent type is effected.
The breeder in this case does not produce the elements
of the variation. He simply observes them, and by selection adds them together until the required result has been
obtained. "No man," says Mr. Darwin, "would ever try
to make a fantail till he saw a pigeon with a tail developed
in some slight degree in an unusual manner, or a pouter
until he saw a pigeon with a crop of unusual size." Thus
Nature gives the hint, man acts upon it, and by the law of
inheritance exaggerates the deviation.
Having thus satisfied himself by indubitable facts that
the organization of an animal or of a plant (for precisely
the same treatment applies to plants) is to some extent
plastic, he passes from variation under domestication to
variation under Nature. Hitherto we have dealt with the
adding together of small changes by the conscious selection of man. Can Nature thus select? Mr. Darwin's
answer is, "Assuredly she can."  The number of living
things produced is far in excess of the number that can be
supported; hence at some period or other of their lives
there must be a struggle for existence; and what is the
infallible result? If one organism  were a perfect copy
of the other in regard to strength, skill, and agility, external conditions would decide. But this is not the case.
Here we have the fact of variety offering itself to Nature,
as in the former instance it offered itself to man; and
those Farieties which are least competent to cope with
surrounding conditions will infallibly give way to those




ADDRESS AT BELFAST.


45


that are most competent. To use a familiar proverb, the
wcakest comnes to the wall. But the triumphant fraction
again breeds to over-production, transmitting the qualities
which secured its maintenance, but transmitting them in
different degrees. The struggle for food again supervenes,
and those to whom the favorable quality has been transmitted
in excess will assuredly triumph. It is easy to see that we
have here the addition of increments favorable to the individual still more rigorously carried out than in the case of
domestication; for not only are unfavorable specimens not
selected by Nature, but they are destroyed. This is what
Mr. Darwin calls " Natural Selection," which " acts by the
preservation and accumulation of small inherited modifications, each profitable to the preserved being."  With this
idea he interpenetrates and leavens the vast store of facts
that he and others have collected. We cannot, without
shutting our eyes through fear or prejudice, fail to see that
Darwin is here dealing, not with imaginary, but with true
causes; nor can we fail to discern what vast modifications
may be produced by natural selection in periods sufficiently long. Each individual increment may resemble
what mathematicians call a " differential" (a quantity
indefinitely small); but definite and great changes may
obviously be produced by the integration of these infinitesimal quantities through practically infinite time.
If Darwin, like Bruno, rejects the notion of creative
power acting after human fashion, it certainly is not because he is unacquainted with the numberless exquisite
adaptations on which this notion of a supernatural artificer
has been founded. His book is a repository of the most
startling facts of this description. Take the marvelous
observation which he cites from D)r. Cruger, where a bucket
with an aperture, serving as a spout, is formed in an
orchid. Bees visit the f.i1wer: in eager search of material
for their combs they push each otlher into the bucket, the




46


PROFESSOR TYNDALL'S


drenched ones escaping from their involuntary bath by the
spout. Here they rub their backs against the viscid stigma
of the flower and obtain glue; then against the pollenmasses, which are thus stuck to the back of the bee and
carried away. " When the bee, so provided, flies to another
flower, or to the same flower a second time, and is pushed
by its comrades into the bucket, and then crawls out by the
passage, the pollen-mass upon its back necessarily comes
first into contact with the viscid stigma," which takes up
the pollen; and this is how that orchid is fertilized. Or
take this other case of the catasetum. " Bees visit these
flowers in order to gnaw the labellum; in doing this they
inevitably touch a long, tapering, sensitive projection.
This, when touched, transmits a sensation of vibration to
a certain membrane, which is instantly ruptured, setting
free a spring, by which the pollen-mass is shot forth like
an arrow in the right direction, and adheres by its viscid
extremity to the back of the bee." In this way the fertilizing pollen is spread abroad.
It is the mind thus stored with the choicest materials
of the teleologist that rejects teleology, seeking to refer
these wonders to natural causes. They illustrate, according
to him, the method of Nature, not the " technic " of a manlike artificer. Trie beauty of flowers is due to natural selection. Those that distinguish themselves by vividly contrasting colors from the surrounding green leaves are most
readily seen, most frequently visited by insects, most often
fertilized, and hence most favored by natural selection.
Colored berries also readily attract the attention of birds
and beasts, which feed upon them, spread their manured
seeds abroad, thus giving trees and shrubs possessing such
berries a greater chance in the struggle for existence.
With profound analytic and synthetic skill, Mr. Darwin
investigates the cell-making instinct of the hive-bee. His
method of dealing with it is representative. He falls back




ADDRESS AT BELFAST.


47


from the more perfectly to the less perfectly developed
instinct-from the hive-bee to the humble-bee, which uses
its own cocoon as a comb, and to classes of bees of intermediate skill, endeavoring to show how the passage might
be gradually made from the lowest to the highest. The
saving of wax is the most important point in the economy
of bees. Twelve to fifteen pounds of dry sugar are said to
be needed for the secretion of a single pound of wax. The
quantities of nectar necessary for the wax must therefore be
vast; and every improvement of constructive instinct which
results in the saving of wax is a direct profit to the insect's
life. The time that would otherwise be devoted to the
making of wax is now devoted to the gathering and storing
of honey for winter food. He passes from the humble-bee
with its rude cells, through the Melipona with its more
artistic cells, to the hive-bee with its astonishing architecture. The bees place themselves at equal distances apart
upon the wax, sweep and excavate equal spheres round the
selected points. The spheres intersect, and the plapes of
intersection are built up with thin laminae. Hexagonal
cells are thus formed. This mode of treating such questions is, as I have said, representative. He habitually
retires from the more perfect and complex to the less perfect and simple, and carries you with him through stages
of perfecting, adds increment to increment of infinitesimal
change, and in this way gradually breaks down your reluctance to admit that the exquisite climax of the whole could
be a result of natural selection.
NMr. Darwin shirks no difficulty; and, saturated as the
subject was with his own thought, he must have known
better than his critics the weakness as well as the strength
of his theory. This of course would be of little avail were
his object a temporary dialectic victory instead of the establishment of a truth which he means to be everlasting. But
he takes no pains to disguise the weakness he has discerned;




48


PROFESSOR TYNDALL'S


nay, he takes every pains to bring it into the strongest
light. His vast resources enable him to cope with objections started by himself and others, so as to leave the final
impression upon the reader's mind that, if they be not completely answered, they certainly are not fatal. Their negative force being thus destroyed, you are free to be influenced by the vast positive mass of evidence he is able to
bring before you. This largeness of knowledge and readiness of resource render Mr. Darwin the most terrible of antagonists. Accomplished naturalists have leveled heavy
and sustained criticisms against him-not always with the
view of fairly weighing his theory, but with the express
intention of exposing its weak points only. This does not
irritate him. He treats every objection with a soberness
and thoroughness which even Bishop Butler might be proud
to imitate, surrounding each fact with its appropriate detail,
placing it in its proper relations, and usually giving it a significance which, as long as it was kept isolated, failed to
appear. This is done without a trace of ill temper. He
moves over the subject with the passionless strength of a
glacier; and the grinding of the rocks is not always without a counterpart in the logical pulverization of the objector.
3But though in handling this mighty theme all passion
has been stilled, there is an emotion of the intellect incident
to the discernment of new truth which often colors and
warms the pages of Mr. Darwin. His success has been
great; and this implies not only the solidity of his work,
but the preparedness of the public mind for such a revelation. On this head a remark of Agatssiz impressed me more
than any thing else. Sprung from a race of theologians,
this celebrated man combated to the last the theory of
natural selection. One of the many times I had the pleasure of meeting him in the United States was at Mr. Winthrop's beautiful residence at Brookline, near Boston. Ris



ADDRESS AT BELFAST.


49


ing from luncheon, we all halted as if by a common impulse
in front of a window, and continued there a discussion which
had been started at table. The maple was in its autumn
glory; and the exquisite beauty of the scene outside seemed,
in my case, to interpenetrate without disturbance the intellectual action. Earnestly, almost sadly, Agassiz turned, and
said to the gentlemen standing round, -' I confess I was not
prepared to see this theory received as it has been by the
best intellects of our time. Its success is greater than I
could have thought possible."
In our day grand gencralizations have been reached.
The theory of the origin of species is but one of them. Another, of still wider grasp and more radical significance, is
the doctrine of the Conscrvr;tion of En-ertv, the ultimate
philosophical issues of whiclh arc as y)ct but dimly seenthat doctrine which " binds Nature fast in fate " to an extent not hitherto recognized, exacting from every antecedent its equivalent consequent, from every consequent its
equivalent antecedent, and bringing vital as well as physical
phenomena under the dominion of that law of causal connection which, so far as the human understanding has yet
pierced, asserts itself everywhere in Nature. Long in advance of all definite experiment upon the subject, the constancy and indestructibility of matter had been affirmed;
and all subsequent experience justified the affirmation.
Later researches extended the attribute of indestructibility
to force. This idea, applied in the first instance to inorganic, rapidly embraced organic Nature. The vegetable
world, though drawing almost all its nutriment from invisible sources, was proved incompetent to generate anew
either matter or force. Its matter is for the most part
transmuted gas; its force transformed solar force. The
animal world was proved to be equally uncreative, all its
motive energies being referred to the combustion of its food.
The activity of each animal as a whole was proved to be




50


PROFESSOR TYNDALL'S


the transferred activity of its molecules. The museles were
shown to be stores of mechanical force, potential until unlocked by the nerves, and then resulting in muscular ccntractions. The speed at which messages fly to and fro along
the nerves was determined, and found to be, not, as had
been previously supposed, equal to that of light or electricity, but less than the speed of a flying eagle.
This was the work of the physicist: then came the conquests of the comparative anatomist and physiologist, revealing the structure of every animal, and the function of
every organ in the whole biological series, from the lowest
zoophyte up to man. The nervous system had been made
the object of profound and continued study, the wonderful
and, at bottom, entirely mysterious, controlling power which
it exercises over. the whole organism, physical and mental,
being recognized more and more. Thought could not Le
kept back from a subject so profoundly suggestive. Besides the physical life dealt with by Mr. Darwin, there is a
psychical life presenting similar gradations, and asking
equally for a solution,. Ilow are the different grades and
orders of mind to be accounted for? What is the principle
of growth of that mysterious power which on our planet
culminates in reasco '~ These are questions which, though
not thrusting thcimsclves so forcibly upon the attention of
the general public, had not only occupied many reflecting
minds, but had been formerly breached by one of them before " The Origin of Species " appeared.
With the mass of materials furnished by the physicist
and physiologist in his hands, A.r. Herbert Spencer,
twenty years ago, sought to graft upon this basis a
system of psychology; and two years ago a second and
greatly amplified edition of his work appeared. Those
who have occupied themselves with the beautiful ex1periments of Plateau will remember that, when two
spherules of olive-oil, suspended in a mixture of alcohol



ADDRESS AT BELFAST.


51


and-water of the same density as the oil, are brought
together, they do not immediately unite. Something like
a pellicle appears to be formed around the drops, the rupture of which is immediately followed by the coalescence
of the globules into one. There are organisms whose
vital actions are almost as purely physical as that of
these drops of oil. They come into contact and fuse
themselves tlius together.  From  such organisms to
others a shade higher, and from these to others a shade
higher still, and on through an ever-ascending series, Mr.
Spencer conducts his argument. There are two obvious
factors to be here taken into account-the creature and
the medium in which it lives, or, as it is often expressed,
the organism and its environment. MA. Spencer's fundamental principle is that btweeen these two factors there is
incessant interaction. T'ie organism is played upon by
the environment, and is modified to meet the requirements
of the environment. Life he defines to be "a continuous
adtjil clilnt of internal relations to external relatiotm-.
in, the lowest organisms we have a kind (, tictual
sense diffused over. the entire body; then, through impressions from without and their corresponding adjustments, special portions of the surface become more
responsive to stimuli than otfeirs. The senses are nascent,
the basis of all cf them being that simple tactual sense
which the sage DemDcritus recognized twenty-three hundred years ago as their common progenitor. The action of
light, in the first instance, appears to be a mere disturbance
of the chemical processes in the animal organism, similar to
that which occurs in the leaves of plants. iBy degrees the
action becomes localized in a few pigment-cells, more
sensitive to light than the surrounding tissue. The eye
is here incipient. At first it is merely capable of revealing differences of light and shade produced by bodies
close at hand. Followed as the interception of the light




52


PROFESSOR TYNDALL'S


is in almost all cases by the contact of the closely adjacent
opaque body, sight in this condition becomes a kind of
" anticipatory touch."  The adjustment continues; a slight
bulging out of the epidermis over the pigment-granules
supervenes. A lens is incipient, and, through the operation of infinite adjustments, at length reaches the perfection that it displays in the hawk and eagle. So of the
other senses; they are special differentiations of a tissue
which was originally vaguely sensitive all over.
With the development of the senses the adjustments
between the organism and its environment gradually extend in space, a multiplication of experiences and a corresponding modification of conduct being the result. The
adjustments also extend in time, covering continually
greater intervals. Along with this extension in space and
time the adjustments also increase in specialty and complexity, passing through the various grades of brute-life,
and prolonging themselves into the domain of reason.
Very striking are Mr. Spencer's remarks regarding the
influence of the sense of touch upon the development of
intelligence. This is, so to say, the mother-tongue of all
the senses, into which they must be translated to be of
service to the organism. Hence its importance. The
parrot is the most intelligent of birds, and its tactual
power is also greatest. From this sense it gets knowledge unattainable by birds which cannot employ their
feet as hands. The elephant is the most sagacious of
quadrupdds-its tactual range and skill, and the consequent multiplication of experiences, which it owes to its
wonderfully adaptable trunk, being the basis of its sagacity.  Feline animals, for a similar cause, are more
sagacious than hoofed animals-atonement being to some
extent made, in the case of the horse, by the possession
of sensitive prehensile lips. In the Primates the evolution of intellect and the evolution of tactual appendages




ADDRESS AT BELFAST.


go hand-in-hand. In the most intelligent anthropoid-apcs
we find the tactual range and delicacy greatly augmented,
new avenues of knowledge being thus open to the animal.
Man crowns the edifice here, not only in virtue of his own
manipulatory power, but through the enormous extension
of his range of experience, by the invention of instruments of precision, which serve as supplemental senses
and supplemental limbs. The reciprocal action of these
is finely described and illustrated. That chastened intellectual emotion to which I have referred in connection
with Mr. Darwin is not absent in Mr. Spencer. His illustrations possess at times exceeding vividness and force;
and from his style on such occasions it is to be inferred
that the ganglia of this Apostle of the Understanding are
sometimes the seat of a nascent poetic thrill.
It is a fact of supreme importance that actions the
performance of which at first requires even painful effort
and deliberation may by habit be rendered automatic.,Witness the slow learning of its letters by a child, and
the subsequent facility of reading in a man, when each
group of letters which forms a word is instantly, and
without effort, fused to a single perception. Instance the
billiard-player, whose muscles of hand and eye, when he
reaches the perfection of his art, are unconsciously coordinated. Instance the musician, who, by practice, is enabled
to fuse a multitude of arrangements, auditory, tactual, and
muscular, into a process of automatic manipulation. Combining such facts with the doctrine of hereditary transmission, we reach a theory of instinct. A chick, after coming
out of the egg, balances itself correctly, runs about, picks
up food, thus showing that it possesses a power of directing its movements to definite ends. How did the chick
learn this very complex coordination of eye, muscles, and
beak? It has not been individually taught; its personal
experience is nil; but it has the benefit of ancestral ex



54


PROFESSOR TYNDALL'S


periellr, In its inherited organization are registered all
the 1) 'wXrs which it displays at birth. So also as regards
the instinct of the hive-bee, already referred to. The distance at which the insects stand apart when they sweep
their hemispheres and build their cells is " organically rememberedl."
Mal also carries with him the physical texture of his
ancestry, as well as the inherited intellect bound up with
it. The defects of intelligence during infancy and youth
are probably less due to a lack of individual experience
than to the fact that in early life the cerebral organization
is still incomplete. The period necessary for completion
varies with the race and with the individual. As a round
shot outstrips a rifled one on quitting the muzzle of the
gun, so the lower race in childhood may outstrip the
higher. But the higher eventually overtakes the lower,
and surpasses it in range. As regards individuals, we do
not always find the precocity of youth prolonged to mental
power in maturity; while the dullness of boyhood is sometimes strikingly contrasted with the intellectual energy of
after-years.  Newton, when a boy, was weakly, and he
showed no particular aptitude at school; but in his
eighteenth year he went to Cambridge, and soon afterward astonished his teachers by his power of dealing with
geometrical problems. During his quiet youth his brain
was slowly preparing itself to be the organ of those
energies which he subsequently displayed.
By myriad blows (to use a Lucretian phrase) the image
and superscription of the external world are stamped as
states of consciousness upon the organism, the depth of
the impression depending upon the number of the blows.
When two or more phenomena occur in the environment
invariably together, they are stamped to the same depth
or to the same relief, and indissolubly connected. And
here we come to the threshold of a great question. Seeing




ADDRESS AT BELFAST.


55


that he could in no way rid himself of the consciousness
of Space and Time, Kant assumed them to be necessary
"forms of intuition," the moulds and shapes into which
our intuitions are thrown, belonging to ourselves solely,
and without objective existence. With unexpected power
and success Mr. Spencer brings the hereditary experience
theory, as he holds it, to bear upon this question. "If
there exist certain external relations which are experienced
by all organisms at all instants of their waking lives-relations which are absolutely constant and universal-there
will be established answering internal relations that are
absolutely constant and universal. Such relations we have
in those of Space and Time. As the substrata of all
other relations of the Non-Ego, they must be responded to
by conceptions that are the substrata of all other relations
in the Ego.  Being the constant and infinitely-repeated
elements of thought, they must become the automatic
elements of thought-the elements of thought which it is
impossible to get rid of-the 'forms of intuition.'"
Throughout this application and extension of the " Law
of Inseparable Association," Mr. Spencer stands upon his
own ground, invoking, instead of the experiences of the
individual, the registered experiences of the race.  His
overthrow of the restriction of experience to the individual
is, I think, complete. That restriction ignores the power
of organizing experience furnished at the outset to each
individual; it ignores the different degrees of this power
possessed by differeont races and by different individuals of
the same race. Were there not in the human brain a potency antecedent to all experience, a dog or cat ought to
be as capable of education as a man. These predetermined
internal relations are independent of the experiences of the
individual. Tiic human brain is the " organized register of
infinitely numerous experiences received during the evoltltion of life, or rather during the evolution of that series of




'56


PROFESSOR TYNDALL'S


organisms through which the human organism has been
reached. The effects of the most uniform and frequent of
these experiences have been successively bequeathed, prin.
cipal and interest, and have slowly mounted to that high
intelligence which lies latent in the brain of the infant.
Thus it happens that the European inherits from twenty to
thirty cubic inches more of brain than the Papuan. Thus
it happens that faculties, as of music, which scarcely exist
in some inferior races, become congenital in-superior ones.
Thus it happens that out of savages unable to count up to
the number of their fingers, and speaking a language containing only nouns and verbs, arise at length our Newtons
and Shakespeares."
At the outset of this Address it was stated that physical theories which lie beyond experience are derived by a
process of abstraction from experience. It is instructive to
note from this point of view the successive introduction of
new conceptions. The idea of the attraction of gravitation
was preceded by the observation of the attraction of iron
by a magnet, and of light bodies by rubbed amber. The
polarity of magnetism and electricity appealed to the
senses, and thus became the substratum of the conception
that atoms and molecules are endowed with definite, attractive, and repellent poles, by the play of which definite forms
of crystalline architecture are produced. Thus molecular
force becomes structural. It requires no great boldness of
thought to extend its play into organic Nature, and to
recognize in molecular force the agency by which both
plants and animals are built up. In this way out of experience arise conceptions which are wholly ultra-experiential. None of the atomists of antiquity had any notion of this play of molecular polar force, but they had experience of gravity as manifested by falling bodies. Abstracting from this, they permitted their atoms to fall eter



ADDRESS AT BELFAST.


57


nally through empty space. Democritus assumed that the
larger atoms moved more rapidly than the smaller ones,
which they therefore could overtake, and with which they
could combine. Epicurus, holding that empty space could
offer no resistance to motion, ascribed to all the atoms the
same velocity; but he seems to have overlooked the consequence that under such circumstances the atoms could
never combine. Lucretius cut the knot by quitting the
domain of physics altogether, and causing the atoms to move
together by a kind of volition.
Was the instinct utterly at fault which caused Lucretius
thus to swerve from his own principles? Diminishing
gradually the number of progenitors, Mr. Darwin comnes at
length to one " primordial form; " but he does not say, as
far as I remember, how he supposes this form to have been
introduced. He quotes with satisfaction the words of a
celebrated author and divine who had " gradually learned
to see that it is just as noble a conception of the Deity to
believe He created a few original forms, capable of selfdevelopment into other and needful forms, as to believe
that Hle required a fresh act of creation to supply the voids
caused by the action of his laws."  What Mr. Dn-linwi
thinks of this view of the introduction of life I do not 1 itw.
But the anthropomorphism, which it seemed his object to
set aside, is as firmly associated with the creation of a
few forms as with the creation of a multitude. We need
clearness and thoroughness here. Two courses, and two
only, are possible. Either let us open our doors freely to
the conception of creative acts, or, abandoning them, let us
radically change our notions of matter. If we look at matter as pictured by Democritus, and as defined for generations in our scientific text-books, the notion of any form of
life whatever coming out of it is utterly unimaginable.
The argument placed in the mouth of Bishop Butler suffices, in my opinion, to crush all such materialism as this.




58


PROFESSOR TYNDALL'S


But those who framed these definitions of matter were not
biologists, but mathematicians, whose labors referred only
to such accidents and properties of matter as could be expressed in their formulae. The very intentness with which
they pursued mechanical science turned their thoughts
aside from the science of life. May not their imperfect
definitions be the real cause of our present dread? Let us
reverently, but honestly, look the question in the face, T)i
vorced from matter, where is life to be found? Whatever
our faith may say, our knowledge shows them to be indissolubly joined. Every meal we eat, and every cup we
drink, illustrates the mysterious control of mind by matter.
t tce the line of life backward, and see it approaching
more and more to what we call the purely physical conditio n. We come at length to those organisms which I have
colm-pared to drops of oil suspended in a mixture of alcoholand-water. We reach the protogenes of Hackel, in which
we have "a type distinguishable from a fragment of albumen only by its finely - granular character." Can we
pause here? We break a magnet and find two poles in
each of its fragments. \Ve continue the process of breaking, but, however small the parts, each carries with it,
though enfeebled, the polarity of the whole. And, when
we can break no longer, we prolong the intellectual vision
to the polar molecules. Are we not urged to do something
similar in the case of life? Is there not a temptation to
close to some extent with Lucretius, when he affirms that
" Nature is seen to do all things spontaneously of herself,
without the meddling of the gods'?" or with Bruno, when
he declares that Matter is not " that mere empty capacity
which philosophers have pictured her to be, but the universal mother who brings forth all things as the fruit of her
own womb? " Believing as I do in the continuity of Nature, I cannot stop abruptly where our microscopes cease to




ALDRESS AT BELFAST.


59


be of use. Here the vision of the mind authoritatively supplements the vision of the eye. By an intellectual necessity I cross the boundary of the experimental evidence, and
discern in that matter which we, in our ignorance of its
latent powers, and notwithstanding our professed reverence
for its creator, have hitherto covered with opprobrium, the
promise and potency of all terrestrial life.
If you ask me whether there exists the least evidence
to prove that any form of life can be developed out of matter, without demonstrable antecedent life, my reply is that
evidence considered perfectly conclusive by many has been
adduced; and that were some of us who have pondered this
question to follow a very common example, and accept testimony because it falls in with our belief, we also should
eagerly close with the evidence referred to. But there is
in the true man of science a wish stronger than the wish to
have his beliefs upheld; namely, the wish to have them
true. And this stronger wish causes him to reject the most
plausible support if he has reason to suspect that it is vitiated by error. Those to whom I refer as having studied
this question, believing the evidence offered in favor of
"spontaneous generation" to be thus vitiated, cannot accept it. They know full well that the chemist now prepares from inorganic matter a vast array of substances
which were some time ago regarded as the sole products of
vitality. They are intimately acquainted with the structural power of matter as evidenced in the phenomena of crystallization. They can justify scientifically their belief in its
potency, under the proper conditions, to produce organisms.
But in reply to your question they will frankly admit their
inability to point to any satisfactory experimental proof
that life can be developed save from demonstrable antecedent litf  As already indicated, they draw the line from
the hig-iiest organisms through lower ones down to the lowest, and it is the prolongation of this line by the intellect




60


PROFESSOR TYNDALL'S


beyond the range of the senses that leads them to the conclusion which Bruno so boldly enunciated.'
The " materialism " here professed lmay be vastly different from what you suppose, and I therefore crave your gracious patience to the end. "The question of an external
world," says Mr. J. S. Mill, "is the great battle-ground of
metaphysics." 2 Mr. Mill himself reduces external phenomena to " possibilities of sensation." Kant, as we have
seen, made time and space " forms" of our own intuitions.
Fichte, having first by the inexorable logic of his understanding proved himself to be a mere link in that chain of
eternal causation which holds so rigidly in Nature, violently
broke the chain by making Nature, and all that it inherits,
an apparition of his own mind.3 And it is by no means
easy to combat such notions. For when I say I see you,
and that I have not the least doubt about it, the reply is
that what I am really conscious of is an affection of my own
retina. And if I urge that I can check my sight of you by
touching you, the retort would be that I am equally transgressing the limits of fact; for what I am really conscious
of is, not that you are there, but that the nerves of my hand
have undergone a change. All we hear, and see, and touch,
and taste, and smell, are, it would be urged, mere variations of our own condition, beyond which, -:en to the extent of a hair's breadth, we cannot go. Thiat any thing answering to our impressions exists outside of ourselves is not
a fact, but an inference, to which all validity would be denied by an idealist like Berkeley, or by a skeptic like Hume.
Mr. Spencer takes another line. With him, as with the
uneducated man, there is no doubt or question as to the
existence of an external world. But he differs from the
uneducated, who think that the world really is what con1 Bruno was a "pantheist," not an " atheist" or a " materialist."
2 "Examination of Hamilton," p. 154.
3 " Bestimmung des Menschen."




ADDRESS AT BELFAST.


61


sciousness represents it to be.   Our states of consciousness
are mere symbols of an outside entity which produces them
and determines the order of their succession, but the real
nature of which we can never know.1        In fact, the whole
process of evolution is the manifestation of a power absolutely inscrutable to the intellect of man.   As little in our
day as in the days of Job can man by searching find this
power out. Considered fundamentally, then, it is by the
operation of an insoluble mystery that life on earth is
evolved, species differentiated, and mind unfolded from their
prepotent elements in the immeasurable past. There is,
you will observe, no very rank materialism here.
The strength of the doctrine of evolution consists, not
in an experimental demonstration (for the subject is hardly
accessible to this mode of proof), but in its general harmony with scientific thought.      From   contrast, moreover,
it derives enormous relative strength. On the one side we
have a theory (if it could with any propriety be so called)
derived, as were the theories referred to at the beginning
of this Address, not from the study of Nature, but from the
observation of men-a theory which converts the power
whose garment is seen in the visible universe into an artifiIn a paper, at once popular and profound, entitled "Recent Progress in
the Theory of Vision," contained in the volume of lectures by Helmholtz,
published by Longmans, this symbolism of our states of consciousness is
also dwelt upon. The impressions of sense are the mere signs of external
things. In this paper Helmholtz contends strongly against the view that
the consciousness of space is inborn; and he evidently doubts the power
of the chick to pick Ap grains of corn without preliminary lessons. On
this point, he says, further experiments are needed. Such experiments
have been since made by Mr. Spalding, aided, I believe, in some of his
observations, by the accomplished and deeply-lamented Lady Amberly;
and they seem to prove conclusively that the chick does not need a single
moment's tuition to enable it to stand, run, govern the muscles of its ees,
and to peck. Helmholtz, however, is contending against the notion of
preestablished harmony; and I am not aware of his views as to the organization of experiences of race or breed.




62


PROFESSOR TYNDALL'S


cer, fashioned after the human model, and acting by broken
efforts as man is seen to act. On the other side we have
the conception that all we see around us, and all we feel
within us-the phenomena of physical Nature as well as
those of the human mind-have their unsearchable roots in
a cosmical life, if I dare apply the term, an infinitesimal span
of which is offered to the investigation of man. And even
this span is only knowable in part. We can trace the development of a nervous system, and correlate with it the
parallel phenomena of sensation and thought. WVe see
with undoubting certainty that they go hand-in-hand. But
we try to soar in a vacuum the moment we seek to comprehend the connection between them. An Archimedean fulcrum is here required which the human mind cannot command; and the effort to solve the problem, to borrow a
comparison from an illustrious friend of mine, is like the
effort of a man trying to lift himself by his own waistband.
All that has been here said is to be taken in connection
with this fundamental truth. When " nascent senses" are
spoken of, when "the differentiation of a tissue at first
vaguely sensitive all over" is spoken of, and when these
processes are associated with " the modification of an
organism by its environment," the same parallelism, without contact, or even approach to contact, is implied. Mlan
the object is separated by an impassable gulf from man the
sudject. There is no motor energy in intellect to carry it
without logical rupture from the one to the other.
Further, the doctrine -of evolution derives ilman in his
totality from the interaction of organism and environment
through countless ages past. The human understanding,
for example-that faculty which Mr. Spencer has turned so
skillfully round upon its own antecedents-is itself a result
of the play between organism and environment through
cosmic ranges of time. Never surely did prescription
plead so irresistible a claim. But then it comes to pass




ADDRESS AT BELFAST.


63


that, over and above his understanding, there are many
other things appertaining to man whose perspective rights
are quite as strong as those of the understanding itself.
It is a result, for example, of the play of organism and environment that sugar is sweet, and that aloes are bitter,
that the smell of henbane differs from the perfume of a rose.
Such facts of consciousness (for which, by-the-way, no adequate reason has yet been rendered) are quite as old as
the understanding; and many other things can boast an
equally ancient origin. Mr. Spencer at one place refers to
that most powerful of passions-the amatory passion-as
one which, when it first occurs, is antecedent to all relative
experience whatever; and we may pass its claim as being
at le atst as ancient and valid as that of the understanding.
T.i( i tliere are some things woven into the texture of man,
as the feeling of awe, reverence, wonder-and not alone
the sexual love just referred to, but the love of the beautiful, physical, and moral, in Nature, poetry, and art. There
is also that deep-set feeling which, since the earliest dawn
of history, and probably for ages prior to all history, incorporated itself in the religions of the world. You who have
escaped from these religions into the high-and-dry light of
the intellect may deride them; but in so doing you deride
accidents of form merely, and fail to touch the immovable
basis of the religious sentiment in the nature of man. To
yield this sentiment reasonable satisfaction is the problem
of problems at the present hour. And grotesque in relation
to scientific culture as many of the religions of the world
have been and are-dangerous, nay, destructive, to the dearest privileges of freemen as some of them undoubtedly have
been, and would, if they could, be again-it will be wise to
recognize them as the forms of a force, mischievous, if permitted to intrude on the region of knowledge, over which it
holds no command, but capable of being guided to noble


a




64


PROFESSOR TYNDALL'S


issues in the region of emotion, which is its proper and elevated sphere.
All religious theories, schemes, and systems, which embrace notions of cosmogony, or which otherwise reach into
the domain of science, must, in so far as they do this, submit to the control of science, and relinquish all thought of
controlling it. Acting otherwise proved disastrous in the
past, and it is simply fatuous to-day. Every system which
would escape the fate of an organism too rigid to adjust
itself to its environment must be plastic to the extent that
the growth of knowledge demands. When this truth has
been thoroughly taken in, rigidity will be relaxed, exclusiveness diminished, things now deemed essential will be
dropped, and elements now rejected will be assimilated.
The lifting of the life is the essential point; and as long
as dogmatism, fanaticism, and intolerance, are kept out,
various modes of leverage may be employed to raise life
to a higher level. Science itself not unfrequently derives
motive power from an ultra-scientific source. Whewell
speaks of enthusiasm of temper as a hinderance to science;
but he means the enthusiasm of weak heads. There is a
strong and resolute enthusiam in which science finds an
ally; and it is to the lowering of this fire, rather than to
the diminution of intellectual insight, that the lessening
productiveness of men of science in their mature years is
to be ascribed. Mr. Buckle sought to detach intellectual
achievement from moral force. He gravely erred; for,
without moral force to whip it into action, the achievements of the intellect would be poor indeed.
it has been said that science divorces itself from literature; but the statement, like so many others, arises from
lack of knowledge. A glance at the less technical writings
of its leaders-of its Helmholtz, its Huxley, and its Du
Bois-Reymond-would show what breadth of literary cult



ADDRESS AT BELFAST.


65


ure they command. Where among modern writers can
you find their superiors in clearness and vigor of literary
style? Science desires not isolation, but freely combines
with every effort toward the bettering of man's estate.
Single-handed, and supported not by outward sympathy,
but by inward force, it has built at least one great wing of
the many-mansioned home which man in his totality demands. I And if rough walls and protruding rafter-ends
indicate that on one side the edifice is still incomplete, it
is only by wise combination of the parts required with those
already irrevocably built that we can hope for completeness. There is no necessary incongruity between what
has been accomplished and what remains to be done. The
moral glow of Socrates, which we all feel by ignition, has
in it nothing incompatible with the physics of Anaxagoras
which he so much scorned, but which he would hardly
scorn to-day.
And here I am reminded of one among us, hoary, but
still strong, whose prophet-voice some thirty years ago, far
more than any other of this age, unlocked whatever of life
and nobleness lay latent in its most gifted minds-one fit
to stand beside Socrates or the Maccabean Eleazar, and to
dare and suffer all that they suffered and dared-fit, as he
once said of Fichte, "to have been the teacher of the Stoa,
and to have discoursed of beauty and virtue in the groves
of Academe." With a capacity to grasp physical principles which his friend Goethe did not possess, and which
even total lack of exercise has not been able to reduce to
atrophy, it is the world's loss that he, in the vigor of his
years, did not open his mind and sympathies to science,
and make its conclusions a portion of his message to mankind. Marvelously endowed as he was-equally equipped
on the side of the heart and of the understanding-he
might have done much toward teaching us how to recon



66


PROFESSOR TYNDALL'S


cile the claims of both, and to enable them in coming
times to dwell together in unity of spirit and in the bond
of peace.
And now the end is come. With more time, or greater
strength and knowledge, what has been here said might
have been better said, while worthy matters here omitted
might have received fit expression. But there would have
been no material deviation from the views set forth. As
regards myself, they are not the growth of a day; and as
regards you, I thought you ought to know the environment which, with or without your consent, is rapidly surrounding you, and in relation to which some adjustment
on your part may be necessary. A hint of Hamlet's, however, teaches us all how the troubles of common life may
be ended; and it is perfectly possible for you and me to
purchase intellectual peace at the price of intellectual
death. The world is not without refuges of this description; nor is it wanting in persons who seek their shelter
and try to persuade others to do the same. The unstable
and the weak will yield to this persuasion, and they to
whom repose is sweeter than the truth. But I would exhort you to refuse the offered shelter and to scorn the base
repose-to accept, if the choice be forced upon you, commotion before stagnation, the leap of the torrent before
the stillness of the swamp.
In the course of this address I have touched on debatable,questions and led you over what will be deemed dangerous ground-and this partly with the view of telling
you that as regards these questions science claims unrestricted right to search. It is not to the point to say that
the views of Lucretius and Bruno, of Darwin and Spencer,
may be wrong. Here I'should agree with you, deeming it
indeed certain that these views will undergo modification.
But tlc point is, that, whether right or wrong, we ask the




ADDRESS AT BELFAST.


67


freedom to discuss them. For science, however, no exclusive claim is here made; you are not urged to erect it into
an idol. The inexorable advance of man's understanding
in the path of knowledge, and those unquenchable claims
of his moral and emotional nature which the understanding
can never satisfy, are here equally set forth. The world
embraces not only a Newton, but a Shakespeare-not only
a Boyle, but a Raphael-not only a Kant, but a Beethoven
-not only a Darwin, but a Carlyle. Not in each of these,
but in all, is human nature whole. They are not opposed,
but supplementary-not mutually exclusive, but reconcilable. And if, unsatisfied with them all, the human mind,
with the yearning of a pilgrim for his distant home, will
turn to the mystery from which it has emerged, seeking so
to fashion it as to give unity to thought and faith; so long
as this is done, not only without intolerance or bigotry of
any kind, but with the enlightened recognition that ult imate fixity of conception is here unattainable, and that
each succeeding age must be held free to fashion the
mystery in accordance with its own needs-then, casting
aside all the restrictions of materialism, I would affirm this
to be a field for the noblest exercise of what, in contrast
with the knowing faculties, may be called the creative
faculties of man.
"Fill thy heart with it," said Goethe, "and then name
it as thou wilt." Goethe himself did this in untranslatable language.1 Wordsworth did it in words known to all
Englishmen, and which may be regarded as a forecast and
religious vitalization of the latest and deepest scientific
truth:
"For I have learned
To look on Nature; not as in the hour
Of thoughtless youth; but hearing oftentimes
The still, sad music of humanity,
1 Proemium to " Gott und Welt."




68    PROFESSOR TYNDALL'S ADDRESS AT BELFAST.
Nor harsh nor grating, though of ample power
To chasten and subdue. And Ihave felt
A presence that disturbs me with the joy
Of elevated thoughts; a sense sublime
Of something far more deeply interfused,
Whose dwelling is the light of setting suns,
And the round ocean, and the living air,
And the blue sky, and in the mind of man:
A motion and a spirit, that impels
All thinking things, all objects of all thought,
And rolls through all things." I
1 Tintern Abbey."


THE END.




Opinions of the Press on the "International Scientific Series."
I.
Tyndall's Forms of Water.
I vol., i2mo.   Cloth.   Illustrated.........   Price, $1.50.
" In the volume now published, Professor Tyndall has presented a noble illustration
of the acuteness and subtlety of his intellectual powers, the scope and insight of his
scientific vision, his singular command of the appropriate language of exposition, and
the peculiar vivacity and grace with which he unfolds the results of intricate scientific
research."-N2. Y. Tribune.
" The 'Forms of Water,' by Professor Tyndall, is an interesting and instructive
little volume, admirably printed and illustrated. Prepared expressly for this series, it
is in some measure a guarantee of the excellence of the volumes that will follow, and an
indication that the publishers will spare no pains to include in the series the freshest investigations of the best scientific minds."-Boston yournal.
" This series is admirably commenced by this little volume from the pen of Prof.
Tyndall. A perfect master of his subject, he presents in a style easy and attractive his
methods of investigation, and the results obtained, and gives to the reader a clear conceptio. of all the wondrous transformations to which water is subjected."-Churchman.
II.
Bagehot's Physics and Politics.
I vol., I2mo.   Price, $I.50.
"If the ' International Scientific Series' proceeds as it has begun, it will more than
fulfil the promise given to the reading public in its prospectus. The first volume, by
Professor Tyndall, was a model of lucid and attractive scientific exposition; and now
we have a second, by Mr. Walter Bagehot, which is not only very lucid and charming,
but also original and suggestive in the highest degree. Nowhere since the publication
of Sir Henry Maine's 'Ancient Law,' have we seen so many fruitful thoughts suggested in the course of a couple of hundred pages... To do justice to Mr. Bagehot's fertile book, would require a long article. With the best of intentions, we are
conscious of having given but a sorry account of it in these brief paragraphs. But we
hope we have said enough to commend it to the attention of the thoughtful reader."Prof. JOHN FISKE, in the Atlantic Monthly.
"Mr. Bagehot's style is clear and vigorous. We refrain from giving a fuller account of these suggestive essays, only because we are sure that our readers will find it
worth their while to peruse the book for themselves; and we sincerely hope that the
forthcoming parts of the 'International Scientific Series' will be as interesting."A theneu nm.
" Mr. Bagehot discusses an immense variety of topics connected with the progress
of societies and nations, and the development of their distinctive peculiarities; and his
book shows an abundance of ingenious and original thought."-ALFRED RUScELI
WALLACE, in Nature.
D. APPLETON        & CO., Publishers, 549 & 551 Broadway, N. Y.




Opintions of the Press on the "International Scientifc Series."
'II.
Foods.
By Dr. EDWARD SMITH.
I vol., I2mo.   Cloth.  Illustrated.......   Price, $I.75.
In making up THE INTERNATIONAL SCIENTIFIC SERIES, Dr. Edward Smith was selected as the ablest man in England to treat the important subject of Foods. His services
were secured for the undertaking, and the little treatise he has produced shows that the
choice of a writer on this subject was most fortunate, as the book is unquestionably the
clearest and best-digested compend of the Science of Foods that has appeared in our
language.
" The book contains a series of diagrams, displaying the effects of sleep and meals
on pulsation and respiration, and of various kinds of food on respiration, which, as the
results of Dr. Smith's own experiments, possess a very high value. We have not far
to go in this work for occasions of favorable criticism; they occur throughout, but are
perhaps most apparent in those parts of the subject A ith which Dr. Smith's name is especially linked."-London Examiner.
"The union of scientific and popular treatment in the composition of this work will
afford an attraction to many readers who would have been indifferent to purely theoretical details.... Still his work abounds in information, much of which is of great value,
and a part of which could not easily be obtained from other sources. Its interest is de.
cidedly enhanced for students who demand both clearness and exactness of statement,
by the profusion of well-executed woodcuts, diagrams, and tables, which accompany the
volume..... The suggestions of the author on the use of tea and coffee, and of the va,
rious forms of alcohol, although perhaps not strictly of a novel character, are highly in.
structive, and form an interesting portion of the volume."-N. Y. Trzbune.
IV.
Body and Mind.
THE THEORIES OF THEIR RELATION.
By ALEXANDER BAIN, LL. D.
I vol., I2mo.    Cloth............     Price, $1.50.
PROFESSOR BAIN is the author of two well-known standard works upon the Science
of Mind-" The Senses and the Intellect," and "The Emotions and the Will." He is
one of the highest living authorities in the school which holds that there can be no sound
or valid psychology unless the mind and the body are studied, as they exist, together.
" It contains a forcible statement of the connection between mind and body, studying their subtile interworkings by the light of the most recent physiological investigations. The summary in Chapter V., of the investigations of Dr. Lionel Beale of the
embodiment of the intellectual functions in the cerebral system, will be found the
freshest and most interesting part of his book. Prof. Bain's own theory of the connection between the mental and the bodily part in man is stated by himself to be as follcw '::
There is ' one substance, with two sets of properties, two sides, the physical and the
mental-a double-faced unity.' While, in the strongest manner, asserting the union
of mind with brain, he yet denies 'the association of union in place,' but asserts the
union of close succession in time,' holding that 'the same being is, by alternate fits, under extended and under unextended consciousness." '-Christian Register.
D. APPLETON & CC)O., Pulishers, 549 &          5I Broadway, N. Y.




Opinions of the Press onz the " International Scientific Seris."
v.
The Study of Sociology.
By HERBERT SPENCER.
I vol., I2mo.   Cloth..............Price, $1.50.
"The philosopher whose distinguished name gives weight and influence to this volume, has given in its pages some of the finest specimens of reasoning in all its forms
and departments. There is a fascination in his array of facts, incidents, and opinions,
which draws on the reader to ascertain his conclusions. The coolness and calmness of
his treatment of acknowledged difficulties and grave objections to his theories win for
him a close attention and sustained effort, on the part of the reader, to comprehend, follow, grasp, and appropriate his principles. This book, independently of its bearing
upon sociology, is valuable as lucidly showing what those essential characteristics are
which entitle any arrangement and connection of facts and deductions to be called a
science. "-Episcopalian.
" This work compels admiration by the evidence which it gives of immense research, study, and observation, and is, withal, written in a popular and very pleasing
style. It is a fascinating work, as well as one of deep practical thought."-bost. Post.
" Herbert Spencer is unquestionably the foremost living thinkerin the psychological
and sociological fields, and this volume is an important contribution to the science of
which it treats... It will prove more popular than any of its author's other creations,
for it is more plainly addressed to the people and has a more practical and less speculative cast. It will require thought, but it is well worth thinking about."-Albaany
Evening yournal.
VI.
The New Chemistry.
By JOSIAH      P. COOKE, JR.,
Erving Professor of Chemistry and Mineralogy in Harvard University.
I vol., I2mo.    Cloth...........     Price, $2.00.
" The book of Prof. Cooke is a model of the modern popular science work. It has
just the due proportion of fact, philosophy, and true romance, to make it a fascinating
companion, either for the voyage or the study."-Daily Graphic.
"This admirable monograph, by the distinguished Erving Professor of Chemistry
in Harvard University, is the first American contribution to 'The International Scientific Series,' and a more attractive piece of work in the way of popular exposition upon
a difficult subject has not appeared in a long time. It not only well sustains the character of the volumes with which it is associated, but its reproduction in European countries will be an honor to American science."-New York Tribune.
" All the chemists in the country will enjoy its perusal. and many will seize upon it
as a thing longed for. For, to those advanced students who have kept well abreast of
the chemical tide, it offers a calm philosophy. To those others, youngest of the class,
who have emerged from the schools since new methods have prevailed, it presents a
generalization, drawing to its use all the data, the relations of which the newly-fledged
fact-seeker may but dimly perceive without its aid..  To the old chemists, Prof.
Cooke's treatise is like a message from beyond the mountain. They have heard of
changes in the science; the clash of the battle of old and new theories has stirred them
from afar. The tidings, too, had come that the old had given way; and little more than
this they knew.... Prof. Cooke's ' New Chemistry' must do wide service in bringing
to close sight the little known and the longed for.... As a philosophy it is elemen.
tary, but, as a book of science, ordinary readers will find it sufficiently advanced."Utica lornting Herald.
D. APPLETON & CO., Publishers, 549 & 551 Broadway, N. Y.




1Opinions of the Press on the " International Scientific Series."
VII.
The Conservation of Energy.
By BALFOUR        STEWART, LL. D., F. R. S.
Withi an Appendix treating of the Vital and J!ental A&plications of the Doctrine.
I vol., I2mo.   Cloth. Price, $i.5o.
"The author has succeeded in presenting the facts in a clear and satisfactory manner,
using simple language and copious illustration in the presentation of facts and principles, confining himself, however, to the physical aspect of the subject. In the Appendix the operation of the principles in the spheres of life and mind is supplied by
the essays of Professors Le Conte and Bain."-Ohio Farmer.
" Prof. Stewart is one of the best known teachers in Owens College in Manchester.
"The volume of THE INTERNATIONAL SCIENTIFIC SERIES now before us is an ex.
cellent illustration of the true method of teaching, and will well compare with Prof.
Tyndall's charming little book in the same series on ' Forms of Water," with illustrations enough to make clear, but not to conceal his thoughts, in a style simple and
brief."-Christian Register, Boston.
"The writer has wonderful ability to compress much information into a few words.
It is a rich treat to read such a book as this, when there is so much beauty and force
combined with such simplicity.-Eastern Press.
VIII.
Animal Locomotion;
Or, WALKING, SWIMMING, AND FLYING.
With a Dissertation on Aeronautics.
By J. BELL PETTIGREW, M. D., F. R. S., F. R. S. E.,
F. R.C. P.E.
I vol., 12mo......   Price, $I.75.
"This work is more than a contribution to the stock of entertaining knowledge,
though, if it only pleased, that would be sufficient excuse for its publication. But Dr.
Pettigrew has given his time to these investigations with the ultimate purpose of solving the difficult problem of Aeronautics. To this he devotes the last fifty pages of his
book. Dr. Pettigrew is confident that man will yet conquer the domain of the air."IN. Y. 57ournal of Commerce.
"Most persons claim to know how to walk, but few could explain the mechanical
principles involved in this most ordinary transaction, and will be surprised that the
movements of bipeds and quadrupeds, the darting and rushing motion of fish, and the
erratic flight of the denizens of the air, are not only anoloeous, but can be reduced to
similar formula. The work is profusely illustrated, and, without reference to the theory
it is designed to expound, will be regarded as a valuable addition to natural history."
-Omaha Republic.
D. APPLETON & CO., PUBLISHERS, 549 & 551 Broadway, N. Y.




THE WORKS OF


Profi JOHN TYNDALL, LL.D., F.R.S.
V.
HOURS OF EXERCISE IN THE ALPS.
One vol., I2mo. With Illustrations. Cloth, $2.00.
" The present volume is for the most part a record of bodily action, written partly to
preserve to myself the memory of strong and joyous hours, and partly for the pleasure of
those who find exhilaration in descriptions associated with mountain-life."-From AUTHOR'S
PREFACE.
VI.
FARADAY AS A DISCOVERER.
One vol., I2mo.    Cloth, $1.00.
"It ha; been thought desirable to give you and the world some image of Michael
Faraday as a scientific investigator and discoverer.......   I have
returned from my task with such results as I could gather, and also with the wish that
these results were more worthy than they are of the greatness of my theme."-The
Author.
VII.
FORMS OF WATER, IN CLOUDS,. RAIN, RIVERS, ICE,
AND CLACIERS.
This is the first volume of the International Scientific Series, and is a valuable and interesting work. One vol., I2mo. Cloth, $1.50.
VIII.
CONTRIBUTIONS TO MOLECULAR PHYSICS IN THE
DOMAIN OF RADIANT HEAT.
A Series of Memoirs published in the " Philosophical Transactions " and
"Philosophical Magazine."      With Additions.
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A New Magazine for Students and Cultivated Readers.
THE
POPULAR SCIENCE MONTHLY,
CONDUCTED BY
Professor E. L. YOUMANS.
THE growing importance of scientific knowledge to all classes of the
community calls for more efficient means of diffusing it. THE POPULAR
SCIENCE MONTHLY has been started to promote this object, and supplies a
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In its literary character, this periodical aims to be popular, without being superficial, and appeals to the intelligent reading-classes of the community. It seeks to procure authentic statements from men who know their
subjects, and who will address the non-scientific public for purposes of exposition and explanation.
It will have contributions from HERBERT SPENCER, Professor HUXLEY,
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THE POPULAR SCIENCE MONTHLY is published in a large
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" A journal which promises to be of eminent value to the cause of popular education in
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