seriously held by sober men, even by men like the illustrious Haller, in
spite of their recognizing that, as the chick grew in the egg, some
changes of form took place. Though so early as the middle of the
eighteenth century Friedrich Casper Wolff, and, later on, others, had
strenuously opposed such a view, it held its own, not only to the close of
the century, but far on into the next. It was not until a quarter of the
nineteenth century had been added to the past that Von Baer made known the
results of researches which once and for all swept away the old view. He
and others working after him made it clear that each individual puts on
its final form and structure, not by an unfolding of preexisting hidden
features, but by the formation of new parts through the continued
differentiation of a primitively simple material. It was also made clear
that the successive changes which the embryo undergoes in its progress
from the ovum to maturity are the expression of morphologic laws; that the
progress is one from the general to the special; and that the shifting
scenes of embryonic life are hints and tokens of lives lived by ancestors
in times long past.
If we wish to measure how far off in biologic thought the end of the
eighteenth century stands, not only from the end, but even from the middle
of the nineteenth, we may imagine Darwin striving to write the "Origin of
Species" in 1799. We may fancy his being told by philosophers how one
group of living beings differed from another group because all its members
and all their ancestors came into existence at one stroke, when the
first-born progenitor of the race, within which all the rest were folded
up, stood forth as the result of a creative act. We may fancy him
listening to a debate between the philosopher who maintained that all the
fossils strewn in the earth were the remains of animals or plants churned
up in the turmoil of a violent universal flood, and dropped in their
places as the waters went away, and him who argued that such were not
really the "spoils of living creatures," but the products of some playful
plastic power which, out of the superabundance of its energy, fashioned
here and there the lifeless earth into forms which imitated, but only
imitated, those of living things. Could he amid such surroundings, by any
flight of genius, have beaten his way to the conception for which his name
will ever be known?
* * * * *
Here I may well turn away from the past. It is not my purpose, nor, as I
have said, am I fitted, nor is this perhaps the place, to tell even in
outline the tale of the work of science in the nineteenth century. I am
content to have pointed out that the two great sciences of chemistry and
geology took their birth, or at least began to stand alone, at the close
of the last century, and have grown to be what we know them now within
about a hundred years, and that the study of living beings has within the
same time been so transformed as to be to-day something wholly different
from what it was in 1799. And, indeed, to say more would be to repeat
almost the same story about other things. If our present knowledge of
electricity is essentially the child of the nineteenth century, so also is
our present knowledge of many other branches of physics. And those most
ancient forms of exact knowledge, the knowledge of numbers and of the
heavens, whose beginning is lost in the remote past, have, with all other
kinds of natural knowledge, moved onward during the whole of the hundred
years with a speed which is ever increasing. I have said, I trust, enough
to justify the statement that in respect to natural knowledge a great gulf
lies between 1799 and 1899. That gulf, moreover, is a twofold one: not
only has natural knowledge been increased, but men have run to and fro,
spreading it as they go. Not only have the few driven far back round the
full circle of natural knowledge the dark clouds of the unknown, which
wrap us all about, but also the many walk in the zone of light thus
increasingly gained. If it be true that the few to-day are, in respect to
natural knowledge, far removed from the few of those days, it is also true
that nearly all which the few alone knew then, and much which they did not
know, has now become the common knowledge of the many.
What, however, I may venture to insist upon here is that the difference in
respect to natural knowledge, whatever be the case with other differences
between then and now, is undoubtedly a difference which means progress.
The span between the science of that time and the science of to-day is
beyond all question a great stride onward.
We may say this, but we must say it without boasting. For the very story
of the past, which tells of the triumphs of science, bids the man of
science put away from him all thoughts of vainglory, and that by many
tokens.
Whoever, working at any scientific problem, has occasion to study the
inquiries into the same problem by some fellow worker in the years long
gone by, comes away from that study humbled by one or other of two
different thoughts. On the one hand, he may find, when he has translated
the language of the past into the phraseology of to-day, how near was his
forerunner of old to the conception which he thought, with pride, was all
his own, not only so true but so new. On the other hand, if the ideas of
the investigator of old, viewed in the light of modern knowledge, are
found to be so wide of the mark as to seem absurd, the smile which begins
to play upon the lips of the modern is checked by the thought, Will the
ideas which I am now putting forth, and which I think explain so clearly,
so fully, the problem in hand, seem to some worker in the far future as
wrong and as fantastic as do these of my forerunner to me? In either case
his personal pride is checked.
Further, there is written clearly on each page of the history of science,
in characters which cannot be overlooked, the lesson that no scientific
truth is born anew, coming by itself and of itself. Each new truth is
always the offspring of something which has gone before, becoming in turn
the parent of something coming after. In this aspect the man of science is
unlike, or seems to be unlike, the poet and the artist. The poet is born,
not made; he rises up, no man knowing his beginnings; when he goes away,
though men after him may sing his songs for centuries, he himself goes
away wholly, having taken with him his mantle, for this he can give to
none other. The man of science is not thus creative: he is created. His
work, however great it be, is not wholly his own: it is in part the
outcome of the work of men who have gone before. Again and again a
conception which has made a name great has come not so much by the man's
own effort as out of the fullness of time. Again and again we may read in
the words of some man of old the outlines of an idea which, in later days,
has shone forth as a great acknowledged truth. From the mouth of the man
of old the idea dropped barren, fruitless; the world was not ready for it,
and heeded it not; the concomitant and abutting truths which could give it
power to work were wanting. Coming back again in later days, the same idea
found the world awaiting it; things were in travail preparing for it, and
someone, seizing the right moment to put it forth again, leaped into fame.
It is not so much the men of science who make science, as some spirit,
which, born of the truths already won, drives the man of science onward
and uses him to win new truths in turn.
It is because each man of science is not his own master, but one of many
obedient servants of an impulse which was at work long before him, and
will work long after him, that in science there is no falling back. In
respect to other things there may be times of darkness and times of light;
there may be risings, decadences, and revivals. In science there is only
progress. The path may not be always a straight line; there may be
swerving to this side and to that; ideas may seem to return again and
again to the same point of the intellectual compass; but it will always be
found that they have reached a higher level--they have moved, not in a
circle, but in a spiral. Moreover, science is not fashioned as is a house,
by putting brick to brick, that which is once put remaining as it was put,
to the end. The growth of science is that of a living being. As in the
embryo, phase follows phase, and each member or body puts on in succession
different appearances, though all the while the same member, so a
scientific conception of one age seems to differ from that of a following
age, though it is the same one in the process of being made; and as the
dim outlines of the early embryo become, as the being grows more distinct
and sharp, like a picture on a screen brought more and more into focus, so
the dim gropings and searchings of the men of science of old are by
repeated approximations wrought into the clear and exact conclusions of
later times.
The story of natural knowledge, of science, in the nineteenth century, as,
indeed, in preceding centuries, is, I repeat, a story of continued
progress. There is in it not so much as a hint of falling back, not even
of standing still. What is gained by scientific inquiry is gained forever;
it may be added to, it may seem to be covered up, but it can never be
taken away. Confident that the progress will go on, we cannot help peering
into the years to come, and straining our eyes to foresee what science
will become and what it will do as they roll on. While we do so, the
thought must come to us: Will all the increasing knowledge of nature
avail only to change the ways of man; will it have no effect on man
himself?
The material good which mankind has gained and is gaining through the
advance of science is so imposing as to be obvious to everyone, and the
praises of this aspect of science are to be found in the mouths of all.
Beyond all doubt, science has greatly lessened and has markedly narrowed
hardship and suffering; beyond all doubt, science has largely increased
and has widely diffused ease and comfort. The appliances of science have,
as it were, covered with a soft cushion the rough places of life, and that
not for the rich only, but also for the poor. So abundant and so prominent
are the material benefits of science, that in the eyes of many these seem
to be the only benefits which she brings. She is often spoken of as if she
were useful and nothing more; as if her work were only to administer to
the material wants of man.
Is this so? We may begin to doubt it when we reflect that the triumphs of
science which bring these material advantages are in their very nature
intellectual triumphs. The increasing benefits brought by science are the
results of man's increasing mastery over nature, and that mastery is
increasingly a mastery of mind; it is an increasing power to use the
forces of what we call inanimate nature in place of the force of his own
or other creatures' bodies; it is an increasing use of mind in place of
muscle.
Is it to be thought that that which has brought the mind so greatly into
play has had no effect on the mind itself? Is that part of the mind which
works out scientific truths a mere slavish machine, producing results it
knows not how, having no part in the good which in its workings it brings
forth?
What are the qualities, the features, of that scientific mind which has
wrought, and is working, such great changes in man's relation to nature?
In seeking an answer to this question we have not to inquire into the
attributes of genius. Though much of the progress of science seems to take
on the form of a series of great steps, each made by some great man, the
distinction in science between the great discoverer and the humble worker
is one of degree only, not of kind. As I was urging just now, the
greatness of many great names in science is often, in large part, the
greatness of occasion, not of absolute power. The qualities which guide
one man to a small truth silently taking its place among its fellows, as
these go to make up progress, are at bottom the same as those by which
another man is led to something of which the whole world rings.
The features of the fruitful scientific mind are, in the main, three.
In the first place, above all other things, his nature must be one which
vibrates in unison with that of which he is in search; the seeker after
truth must himself be truthful, truthful with the truthfulness of nature.
For the truthfulness of nature is not wholly the same as that which man
sometimes calls truthfulness. It is far more imperious, far more exacting.
Man, unscientific man, is often content with the "nearly" and the
"almost." Nature never is. It is not her way to call the same two things
which differ, though the difference may be measured by less than a
thousandth of a milligramme or of a millimetre, or by any other like
standard of minuteness. And the man who, carrying the ways of the world
into the domain of science, thinks that he may treat nature's differences
in any other way than she treats them herself, will find that she resents
his conduct; if he, in carelessness or in disdain, overlooks the minute
difference which she holds out to him as a signet to guide him in his
search, the projecting tip, as it were, of some buried treasure, he is
bound to go astray, and the more strenuously he struggles on, the further
he will find himself from his true goal.
In the second place, he must be alert of mind. Nature is ever making signs
to us; she is ever whispering to us the beginnings of her secrets; the
scientific man must be ever on the watch, ready at once to lay hold of
nature's hint, however small; to listen to her whisper, however low.
In the third place, scientific inquiry, though it be preeminently an
intellectual effort, has need of the moral quality of courage--not so much
the courage which helps a man to face a sudden difficulty as the courage
of steadfast endurance. Almost every inquiry, certainly every prolonged
inquiry, sooner or later goes wrong. The path, at first so straight and
clear, grows crooked and gets blocked; the hope and enthusiasm, or even
the jaunty ease, with which the inquirer set out, leave him, and he falls
into a slough of despond. That is the critical moment calling for courage.
Struggling through the slough, he will find on the other side the wicket
gate opening up the real path; losing heart, he will turn back and add one
more stone to the great cairn of the unaccomplished.
But, I hear someone say, these qualities are not the peculiar attributes
of the man of science: they may be recognized as belonging to almost
everyone who has commanded or deserved success, whatever may have been his
walk of life. That is so. That is exactly what I desire to insist, that
the men of science have no peculiar virtues, no special powers. They are
ordinary men, their characters are common, even commonplace. Science, as
Huxley said, is organized common sense, and men of science are common men
drilled in the ways of common sense. For their life has this feature.
Though in themselves they are no stronger, no better than other men, they
possess a strength which, as I just now urged, is not their own, but is
that of the science whose servants they are. Even in his apprenticeship,
the scientific inquirer, while learning what has been done before his
time, if he learns it aright, so learns it that what is known may serve
him, not only as a vantage-ground whence to push off into the unknown, but
also as a compass to guide him in his course. And when, fitted for his
work, he enters on inquiry itself, what a zealous, anxious guide, what a
strict and, because strict, helpful, schoolmistress does Nature make
herself to him! Under her care every inquiry, whether it bring the
inquirer to a happy issue or seem to end in nought, trains him for the
next effort. She so orders her ways that each act of obedience to her
makes the next act easier for him; and step by step she leads him on
toward that perfect obedience which is complete mastery.
Indeed, when we reflect on the potency of the discipline of scientific
inquiry, we cease to wonder at the progress of scientific knowledge. The
results actually gained seem to fall so far short of what under such
guidance might have been expected to have been gathered in, that we are
fain to conclude that science has called to follow her, for the most part,
the poor in intellect and the wayward in spirit. Had she called to her
service the many acute minds who have wasted their strength struggling in
vain to solve hopeless problems, or who have turned their energies to
things other than the increase of knowledge; had she called to her service
the many just men who have walked straight without the need of a rod to
guide them, how much greater than it has been would have been the progress
of science, and how many false teachings would the world have been spared!
To men of science themselves, when they consider their favored lot, the
achievements of the past should serve, not as a boast, but as a reproach.
If there be any truth in what I have been urging, that the pursuit of
scientific inquiry is itself a training of special potency, giving
strength to the feeble and keeping in the path those who are inclined to
stray, it is obvious that the material gains of science, great as they may
be, do not make up all the good which science brings, or may bring, to
man. We especially, perhaps, in these later days, through the rapid
development of the physical sciences, are too apt to dwell on the material
gains alone. As a child in its infancy looks upon its mother only as a
giver of good things, and does not learn till after days how she was also
showing her love by carefully training it in the way it should go, so we,
too, have thought too much of the gifts of science, overlooking her power
to guide.
Man does not live by bread alone, and science brings him more than bread.
It is a great thing to make two blades of grass grow where before one
alone grew; but it is no less great a thing to help a man to come to a
just conclusion on the questions with which he has to deal. We may claim
for science that, while she is doing the one, she may be so used as to do
the other also. The dictum just quoted, that science is organized common
sense, may be read as meaning that the common problems of life, which
common people have to solve, are to be solved by the same methods by which
the man of science solves his special problems. It follows that the
training which does so much for him may be looked to as promising to do
much for them.
Such aid can come from science on two conditions only. In the first place,
this her influence must be acknowledged; she must be duly recognized as a
teacher no less than as a hewer of wood and a drawer of water. And the
pursuit of science must be followed, not by the professional few only, but
at least in such measure as will ensure the influence of example by the
many. But this latter point I need not urge before this great
association, whose chief object during more than half a century has been
to bring within the fold of science all who would answer to the call. In
the second place, it must be understood that the training to be looked for
from science is the outcome, not of the accumulation of scientific
knowledge, but of the practice of scientific inquiry. Man may have at his
fingers' ends all the accomplished results and all the current opinions of
any one or of all the branches of science, and yet remain wholly
unscientific in mind; but no one can have carried out even the humblest
research without the spirit of science in some measure resting upon him.
And that spirit may in part be caught even without entering upon an actual
investigation in search of a new truth. The learner may be led to old
truths, even the oldest, in more ways than one. He may be brought abruptly
to a truth in its finished form, coming straight to it like a thief
climbing over the wall; and the hurry and press of modern life tempt many
to adopt this quicker way. Or he may be more slowly guided along the path
by which the truth was reached by him who first laid hold of it. It is by
this latter way of learning the truth, and by this alone, that the learner
may hope to catch something at least of the spirit of the scientific
inquirer.
This is not the place, nor have I the wish, to plunge into the turmoil of
controversy; but if there be any truth in what I have been urging, then
they are wrong who think that in the schooling of the young science can be
used with profit only to train those for whom science will be the means of
earning their bread. It may be that, from the point of view of pedagogic
art, the experience of generations has fashioned out of the older studies
of literature an instrument of discipline of unusual power, and that the
teaching of science is as yet but a rough tool in unpractised hands. That,
however, is not an adequate reason why scope should not be given for
science to show the value which we claim for it as an intellectual
training fitted for all sorts and conditions of men. Nor need the studies
of humanity and literature fear her presence in the schools; for if her
friends maintain that the teaching is one-sided, and therefore misleading,
which deals with the doings of man only, and is silent about the works of
nature, in the sight of which he and his doings shrink almost to nothing,
she herself would be the first to admit that that teaching is equally
wrong which deals only with the works of nature and says nothing about the
doings of man, who is, to us at least, nature's centre.
There is yet another general aspect of science on which I would crave
leave to say a word. In that broad field of human life which we call
politics, in the struggle, not of man with man, but of race with race,
science works for good. If we look only on the surface, it may at first
sight seem otherwise. In no branch of science has there during these later
years been greater activity and more rapid progress than in that which
furnishes the means by which man brings death, suffering, and disaster on
his fellow men. If the healer can look with pride on the increased power
which science has given him to alleviate human suffering and ward off the
miseries of disease, the destroyer can look with still greater pride on
the power which science has given him to sweep away lives and to work
desolation and ruin; while the one has slowly been learning to save units,
the other has quickly learned to slay thousands. But, happily, the very
greatness of the modern power of destruction is already becoming a bar to
its use, and bids fair--may we hope before long--wholly to put an end to
it; in the words of Tacitus, though in another sense, the very
preparations for war, through the character which science gives them, make
for peace.
Moreover, not in one branch of science only, but in all, there is a deep
undercurrent of influence sapping the very foundations of all war. As I
have already urged, no feature of scientific inquiry is more marked than
the dependence of each step forward on other steps which have been made
before. The man of science cannot sit by himself in his own cave, weaving
out results by his own efforts, unaided by others, heedless of what others
have done and are doing. He is but a bit of a great system, a joint in a
great machine, and he can only work aright when he is in due touch with
his fellow workers. If his labor is to be what it ought to be, and is to
have the weight which it ought to have, he must know what is being done,
not by himself, but by others, and by others not of his own land and
speaking his tongue only, but also of other lands and of other speech.
Hence it comes about that to the man of science the barriers of manners
and of speech which pen men into nations become more and more unreal and
indistinct. He recognizes his fellow worker, wherever he may live, and
whatever tongue he may speak, as one who is pushing forward shoulder to
shoulder with him toward a common goal, as one whom he is helping and who
is helping him. The touch of science makes the whole world kin.