DARWIN: THE THINKER
I
Mere observation of the natural world, varied, fascinating,
inexhaustible as it is, affords only the material for science.
Observed facts must be built up, woven together, ordered, arranged,
systematized into conclusions and theories by reflection and
reason, if they are to have full bearing on life and the universe.
Knowledge is the accumulation of facts. Wisdom is the establishment
of relations. And just because the latter process is delicate and
perilous, it is all the more delightful. The lofty scorn of the true
philosopher for mere perception is well shown in Royer Collard’s
remark: ‘There is nothing so despicable as a fact.’ Which does not
prevent philosophers or any one else from making facts the essential
basis of all discussion of relations. Darwin’s own comments on the
general connection between the two are always interesting: ‘I have an
old belief that a good observer really means a good theorist,’[432]
and again: ‘About thirty years ago there was much talk that
geologists ought only to observe and not theorize; and I well
remember some one saying that at this rate a man might as well go
into a gravel-pit and count the pebbles and describe the colors. How
odd it is that any one should not see that all observation must be
for or against some view if it is to be of any service.’[433]
It is supposed to be one of the chief functions of education to
develop this faculty of relating facts to each other and to train and
strengthen the reasoning powers. Darwin did not feel that education
did much for him in this line, at any rate in the scientific
directions which were of especial interest to him. He believed that
his academic discipline was largely wasted. Making Latin verses did
not appeal. More general lines of current information attracted
him very little, and he seemed at times oddly ignorant of what the
ordinary educated man is expected to know. Thus his son records that
he once asked Hooker where ‘this place Wien is where they publish so
many books.’[434] He read vastly in all that concerned his own work,
but that very fact prevented his keeping up with daily interests that
were remote from it. His own comment on his university experience is
bitter: ‘During the three years which I spent at Cambridge my time
was wasted, as far as the academical studies were concerned, as
completely as at Edinburgh and at school.’[435] And he believed that
he had learned everything that to him was worth learning pretty much
by his own efforts: ‘I consider that all I have learnt of any value
has been self-taught.’[436]
[Illustration: DOWN HOUSE FROM THE GARDEN]
With this sort of discipline behind him, it is of great interest to
examine his general attitude toward the connection of reasoning and
fact. To some of us the controversy between induction and deduction
has always seemed rather profitless. The Baconian insistence upon
the absolute necessity of fact as the basis of all solid theory is
of course indisputably just. But to talk of proceeding from abstract
theory to the investigation of fact seems as barren as to wander
aimlessly in unassorted realms of fact without the assistance of
theory. It is comforting, therefore, to find so clear and systematic
a thinker as Huxley unwilling to identify his processes with either
complete induction or deduction: ‘Those who refuse to go beyond fact
rarely get as far as fact; and any one who has studied the history of
science knows that almost every great step therein has been made by
the “anticipation of nature,” that is, by the invention of hypotheses
which, though verifiable, often had very little foundation to start
with; and not unfrequently, in spite of a long career of usefulness,
turned out to be wholly erroneous in the long run.’[437]
Now Darwin obviously finds himself in precisely the uncertainty
between inductive and deductive methods that Huxley here indicates.
His instincts were naturally hostile to abstract theory, which used
facts as playthings to substantiate soaring conjecture. He says in
regard to one scientific author: ‘I am not convinced, partly I think
owing to the deductive cast of much of his reasoning; and I know not
why, but I never feel convinced by deduction, even in the case of
H. Spencer’s writings.’[438] And he speaks even more specifically
concerning Spencer himself: ‘I always feel a malicious pleasure
when _a priori_ conclusions are knocked on the head; and therefore
I felt somewhat like a devil when I read your remarks on Herbert
Spencer.’[439] Early and late he emphasized that ‘no one has a right
to speculate without distinct facts.’[440] Yet at the same time he
urges and reiterates that the mere collection of facts, without
some basis of theory for guidance and elucidation, is foolish and
profitless: ‘I am a firm believer that without speculation there is
no good and original observation.’[441]
The truth is, the importance of imaginative power in the equipment of
a great scientist is often underestimated. Exact and watchful vision
is the first necessity; but it does not go far, or not farthest,
except as it has behind it the thoughts that wander through eternity,
the vast and questing genius that is perpetually on the lookout for
causes and explanations and is eager to evolve theory from the sure
and substantial but inanimate basis of fact. Even Thoreau almost
deplores his intense preoccupation with the fascinating business of
observing: ‘Man cannot afford to be a naturalist, to look at Nature
directly, but only with the side of his eye. He must look through and
beyond her. To look at her is fatal as to look at the head of Medusa.
It turns the man of science to stone. I feel that I am dissipated
by so many observations.... I have almost a slight, dry headache as
the result of all this observing.’[442] Theory, speculation, must be
perpetually checked and restrained by the precision of systematic
logic, but the accurate eye and the careful finger need to be
supplemented by the eternally active mind.
As to the activity of Darwin’s mind there can be no question
whatever. He not only saw, but he thought incessantly. If you compare
the Beagle Journal with the Journal of Thoreau, you see at once how
much more quick and ready the English naturalist is with speculation
and conjecture. The smallest fact is apt to set him off on a train
of theory, where Thoreau simply records, or possibly compares, and
passes on. How significant is the brief comment of Asa Gray, in
regard to some botanical point which as a specialist in that line he
should have been the first to develop: ‘That is real Darwin. I just
wonder you and I never thought of it. But _he_ did.’[443] And he not
only thought himself, he had the rarer and more valuable faculty of
making others think. His mind was so intense and so magnetic in its
constant activity that all those who came into contact with it were
impelled and fired to work double on speculation of their own. ‘You
stimulate my mind,’ says Gray again, ‘far more than any one else,
except, perhaps Hooker.’[444]
On this point of intellectual fertility, as on his other scientific
qualifications, it is most interesting to hear Darwin himself. The
mental activity was present early and late, and it does not appear
that the exuberance of youth especially emphasized it or that it
tended to increase with the later desire to develop and elaborate his
special theories. He himself says in the Autobiographical sketch:
‘I am not conscious of any change in my mind during the last thirty
years, excepting in one point: ... I think that I have become a
little more skillful in guessing right explanations and in devising
experimental tests; but this may probably be the result of mere
practice, and of a larger store of knowledge.’[445]
The quick intelligence was always working, sometimes wearily,
sometimes eagerly, but working, unless absolute physical prostration
forbade. When he is too exhausted, he complains: ‘Facts compel me to
conclude that my brain was never formed for much thinking.’[446] But
if so, he certainly lived contrary to his nature. He tells us that he
cannot resist forming hypotheses on every subject.[447] Sometimes he
bewails the tendency, realizing its drawbacks and dangers. Sometimes
he gives way to it, recognizing its charm: ‘It is delightful to
have many points fermenting in one’s brain.’[448] Speculation is
fascinating. Theory gives form and texture to the fleeting drift and
confusion of fact. Yet even when one indulges with most enthusiasm,
a touch of humor shows that the satisfaction must be tempered with a
certain lack of entire confidence: ‘That is a splendid fact about the
white moths; it warms one’s very blood to see a theory thus almost
proved to be true.’[449]
For the wonder and the interest of Darwin is, that, with such an
eager and perpetual bent toward theorizing, he could keep the bent
so fully under control. As Karl Pearson puts it, generally: ‘Hundreds
of men have allowed their imagination to solve the universe, but
the men who have contributed to our real understanding of natural
phenomena have been those who were unstinted in their application
of criticism to the product of their imaginations.’[450] Surely no
man applied such criticism more carefully, more conscientiously,
more constantly than Darwin. He analyzes his own position and sees
the dangers of it: ‘Living so solitary as I do, one gets to think
in a silly manner of one’s own work.’[451] He sees constantly how
theory interferes and warps the judgment: ‘I have not a doubt that
before many months are over I shall be longing for the most dishonest
species as being more honest than the honestest theories.’[452] The
possibility of error haunts him, torments him, and he knows well how
apt his own speculative disposition is to mislead: ‘What you hint
at generally is very, very true: that my work will be grievously
hypothetical, and large parts by no means worthy of being called
induction, my commonest error being probably induction from too few
facts.’[453] As a consequence he was ever on his guard against being
led astray. The tempting little demon of hypothesis might be luring
round the corner: ‘It is as difficult not to form some opinion as
it is to form a correct judgment.’[454] But whatever opinion was
formed must be corrected, must be adjusted, must be tested, by the
cold and rigid measure of fact. As he says himself, ‘I have steadily
endeavored to keep my mind free so as to give up any hypothesis,
however much beloved (and I cannot resist forming one on every
subject), as soon as the facts are shown to be opposed to it.’[455]
And one who knew him well and had studied him carefully says the same
thing with equal emphasis: ‘His long experience had given him a kind
of instinctive insight into the method of attack of any biological
problem, however unfamiliar to him, while he rigidly controlled the
fertility of his mind in hypothetical explanations by the no less
fertility of ingeniously devised experiment.’[456]
In regard to this matter of speculative freedom and the tendency
to let imagination run wild, it is interesting to watch Darwin’s
comments on the general methods of others. The excess of abstinence
he indeed deplores, recognizing that a man’s extreme caution may
prevent him from theorizing enough: ‘How many astronomers have
labored their whole lives on observations, and have not drawn a
single conclusion.’[457] But the danger on the other side is so great
and so ruinous that it cannot be enough insisted on, and indeed at
times it makes all generalization suspicious and almost a thing
to be eschewed: ‘I look at a strong tendency to generalize as an
entire evil.’[458] At any rate, the theorist must never forget the
subjective element, that his preconceptions and prejudices are apt
to warp his judgment and distort his vision, till the keenest of
observers and the sanest of thinkers may go astray: ‘the firmest
conviction of the truth of a doctrine by its author seems, alas, not
to be the slightest guarantee of truth.’[459]
The profit and the lesson of all which must be constantly borne home
to oneself: ‘When I think of the many cases of men who have studied
one subject for years, and have persuaded themselves of the truth
of the foolishest doctrines, I feel sometimes a little frightened,
whether I may not be one of these monomaniacs.’[460]
To appreciate fully Darwin’s combination of mental activity and
fertility with moderation and restraint, it is well to place him
between two extreme types of thinkers. On the one hand, there is
the born essential reasoner, and logician, Spinoza, for instance,
or Hegel, or Darwin’s own contemporary, Spencer, the man who to
a greater or less extent takes fact for his foundation, but who
by nature and temperament delights to weave an elaborate web of
logical theory, rigid and perfect in its appearance of systematic
deduction, but too apt in the end to treat facts with indifference if
not disrespect. I like especially in this regard to compare Darwin
with Lucretius. The _De Rerum Natura_ is one of the most striking,
enthralling examples of what I should call passionate thinking.
Theoretical problems take hold of Lucretius like the ecstasies of
love. He tears and wrenches at the roots of thought, determined to
make them yield to the delving vigor of his eager search. Now Darwin
has a broad and constant curiosity, his interest may well be called
enthusiasm, and he himself uses the term passion for it: ‘Hence it
has come to be a passion with me to try to connect all such facts by
some sort of hypothesis.’[461] Yet in no phase of his nature should I
be inclined ever to employ the general word, ‘passion,’ and it seems
to me that every page of Lucretius is stamped with a devouring ardor
different from anything Darwin knew.
On the other hand, over against these furious reasoners, I should
set Darwin’s close contemporary, Sainte-Beuve, who, as I said in the
previous chapter was, in some aspects, as admirable a representative
of the scientific spirit as Darwin himself. The endless curiosity,
the unlimited observation of fact, as embodied in the human subject,
have never been more richly exemplified than in the great French
critic. But Sainte-Beuve was no reasoner in the larger sense. He
did not even avoid reasoning from mistrust: he had no taste for it,
and when he dealt with it, it was always charily and with extreme
reserve. He delighted to study and portray individuals and to allow
those individuals, as it were, to classify themselves and so to point
the way to general results.
Between these two extremes Darwin stands, as one who used reasoning
to the fullest extent for the interpretation of fact, yet at the same
time always stuck closely and rigidly to the fact itself, and would
not allow it to be for an instant distorted by the reasoning process.
II
The supreme means for keeping theory on a basis of fact is of course
unfailing, persistent, ever-varied experiment. In the preceding
chapter we have seen observation lead naturally to experiment; but
experiment is observation guided, directed, and illuminated by
theory. And assuredly no scientist ever had the love and the habit
of experiment more firmly fixed than Darwin. The explanation of
phenomena was all very well in its place, essential, absorbing, but
he would have agreed absolutely with Aristotle as to the proper
ordering of the process: ‘After this we shall pass on to the
discussion of causes. For to do this when the investigation of the
details is complete, is the proper and natural method, and that
whereby the subject and the premises of our argument will afterwards
be rendered plain.’[462] The fascination of experiment in itself
was endless and almost sufficing: ‘The love of experiment was very
strong in him,’ says his son, ‘and I can remember the way he would
say, “I shan’t be easy till I have tried it,” as if an outside force
were driving him.’[463] There was a sense of adventure about it, of
discovery, and he loved to try things that seemed almost fantastic
and absurd: ‘If you knew some of the experiments (if they may be
so-called) which I am trying, you would have a good right to sneer,
for they are so _absurd_ even in _my_ opinion that I dare not tell
you.’[464] And more concisely and vividly: ‘I am like a gambler
and love a wild experiment.’[465] The best comment on which is the
excellent remark of Professor Castle: ‘Most advances in practical
affairs are made by those who have the courage to attempt what others
_with good reason think unattainable_. When such attempts have
succeeded, the world simply revises its classification of things
attainable and unattainable, and makes a fresh start.’[466]
The first thing in regard to experiment is conditions. There are
of course rough and elementary experiments, involving only simple
principles, which do not require minute care in detail. But in many
cases the nicest and most delicate preparation and adjustment are
indispensable to ensure reliable results. The extensive equipment of
modern laboratories was not at Darwin’s command, and though he had
considerable financial resources, he could not afford the unlimited
outlay of commercial research. Thus, we read of one of Mr. Burbank’s
trials: ‘Forty thousand blackberry and raspberry hybrids were
produced and grown until the fruit matured. Then from the whole lot
a single variety was chosen as the best.... All others were uprooted
with their crop of ripening berries, heaped up into a pile twelve
feet wide, fourteen feet high, and twenty-two feet long, and burned.
Nothing remained of this expensive and lengthy experiment, except
the one parent plant of the new variety.’[467] Darwin could hardly
work on any such elaborate scale as this. Yet, as one turns over his
vast record of experiment, one is astonished to see how thorough
and painstaking was his effort to avoid accidents and to provide
for disturbing contingencies. Take, for instance, as a minor but
significant illustration, his account of the difficulty in carrying
out the specific fertilization of certain plants: ‘In making eighteen
different unions, sometimes on windy days, and pestered by bees and
flies buzzing about, some few errors could hardly be avoided. One
day I had to keep a third man by me all the time to prevent the bees
visiting the uncovered plants, for in a few seconds’ time they might
have done irreparable mischief. It was also extremely difficult to
exclude minute Diptera from the net.’[468]
Another vital consideration as to experiment, is that it should be
kept impersonal. In most cases, if one is to experiment fruitfully
and satisfactorily, there should be some special object in view, some
particular point to be rejected or confirmed. Unless you know just
what you are looking for, you are apt not to see. Again and again in
Darwin’s book on Orchids, as in many of the others, we read that he
made investigations and got no results, simply because he did not
have in mind theoretical possibilities. When he had reasoned out
what ought to happen or might happen, he often found that it did.
The danger of this method is obvious. When the experimenter is so
desperately anxious to see something, unless he is most carefully
trained and disciplined, he will see it. It is not to be supposed
that Darwin always escaped this danger, but few men have been more
prepared for it or more ready to allow for it than he. His confession
of prejudice, his recognition of the importance of certain points
in his general theory and of his unwillingness to have anything
interfere with them are among his greatest charms: ‘I remember well
the time when the thought of the eye made me cold all over.... The
sight of a feather in a peacock’s tail, whenever I gaze at it, makes
me sick.’[469]
We have already enlarged under observation on the essential quality
of accuracy, and it may simply be added that accuracy is doubly
important in all experiments for a theoretical purpose. Accuracy,
complete, detailed, mathematical exactitude, was Darwin’s hobby, and
the minuteness of his record constantly exemplifies it.
Also, to confirm their accuracy experiments have to be repeated.
Goethe remarks with justice that it is not necessary to travel all
over the world to make sure that the sky is everywhere blue,[470] and
no doubt there are repetitions that are vain and superfluous. But
many difficult and delicate researches have to be gone over again
and again that the minutest detail may be complete; and the process
may involve months of tedious delay. Darwin’s unfailing care, both
to repeat and to avoid repetition, is well indicated in his son’s
comment: ‘Although he would patiently go on repeating experiments
where there was any good to be gained, he could not endure having to
repeat an experiment which ought, if complete care had been taken, to
have succeeded the first time.’[471] Here too, one cannot appreciate
how immense and thorough his experimentation was without looking
through such books as the ‘Animals and Plants under Domestication’ or
‘The Power of Movement in Plants.’ The endless repetition of slightly
varied combinations to test a difficult or remote conclusion makes
one feel how persistent and inexhaustible the patience was. And after
all the years of repeated and varied research and investigation he
writes the almost pathetic epilogue six months before his death: ‘I
wish that I had enough strength and spirit to commence a fresh set of
experiments, and publish the results, with a full recantation of my
errors when convinced of them.’[429]
Finally, experiments have to be not only made, but recorded, and the
accuracy, so essential with all scientific observation, is above
all essential here, since the omission of a link in the record may
be ruinous to the continuity of the logical chain. It is peculiarly
characteristic of Darwin that he wanted the record of error and
mistake as well as of success. ‘I remember,’ says his son, ‘how
strongly he urged the necessity of keeping the notes of experiments
which failed, and to this rule he always adhered.’[430] The value of
preserving and comparing apparently insignificant and meaningless
notes is sometimes brought out, as in a special case of orchids: ‘I
had given up the case as hopeless, until summing up my observations,
the explanation presently to be given, and subsequently proved by
repeated experiments to be correct, suddenly occurred to me.’[431]
Long experience of his own mistakes and failures induces extreme
scepticism as to the results of others: ‘_The difficulty is to know
what to trust_.’[352] Even when he has taken the greatest pains,
the scepticism often lingers and forces him to repeat although with
an identical result: ‘Notwithstanding the care taken and the number
of trials made, when in the following year I looked merely at the
results, without reading over my observations, I again thought that
there must have been some error, and thirty-five fresh trials were
made with the weakest solution; but the results were as plainly
marked as before.’[353] And thus the long series of packed, closely
printed volumes forms an amazing record of a life of zealous,
persistent, curious experimentation from beginning to end.
III
Now let us look a little more closely at the stuff and quality of
Darwin’s logical processes, considered as such. He himself often
complains of the slowness and difficulty of his thinking. It is hard
for him to arrange his thoughts, he says, hard for him to get them
into the lucid and effective order which carries conviction with
it, almost enforces conviction by the power of its own movement. He
says of one of his critics: ‘He admits to a certain extent Natural
Selection, yet I am sure does not understand me. It is strange that
very few do, and I am become quite convinced that I must be an
extremely bad explainer.’[354]
It is worth while to note the comments of Huxley, as one of Darwin’s
staunchest friends and supporters, on his reasoning faculty and
processes. When Romanes lauds Darwin’s colossal intellect, Huxley is
inclined to protest: ‘Colossal does not seem to me to be the right
epithet for Darwin’s intellect. He had a clear, rapid intelligence,
a great memory, a vivid imagination, and what made his greatness was
the strict subordination of all these to the love of truth.’[355]
Elsewhere Huxley adds: ‘Exposition was not Darwin’s forte—and his
English is sometimes wonderful. But there is a marvelous dumb
sagacity about him and he gets to truth by ways as dark as those of
the Heathen Chinee.’[356] Of ‘The Origin of Species’ Huxley writes:
‘It is one of the hardest books to understand thoroughly that I know
of.’[357] And again, more amply: ‘Long occupation with the work has
led the present writer to believe that “The Origin of Species” is
one of the hardest of books to master, and he is justified in this
conviction by observing that although the “Origin” has been close on
thirty years before the world, the strangest misconceptions of the
essential nature of the theory therein advocated are still put forth
by serious writers.’[358] Critics less friendly to Darwin than Huxley
have spoken still more strongly.
I feel that Huxley’s judgment is too severe. It is true that Darwin
had not the admirable gift of logical, lucid exposition which made
Huxley himself one of the most luminous of scientific writers. But
even when Darwin’s reasoning is most complex and difficult, there
is a notable quality of sincerity and single-mindedness, which wins
and retains your confidence. He seems somehow to have an exceptional
power of taking you into his mental processes, and to make you think
and see and feel as he does. If you feel that he may be wrong, it is
because he feels that he may be wrong himself.
It is profitable to examine a little more in detail some
illustrations of Darwin’s scientific theorizing. The great central
doctrine of evolution, with its buttressing support of natural
selection, will fill our next chapter, but there are several lesser
developments of speculation which deserve notice. I need hardly say
that we are not in any way discussing the validity of the theories in
the abstract, but simply Darwin’s fashion of framing, holding, and
sustaining them.
There is first the theory as to the formation of coral reefs. At
an early period in his career Darwin conceived the idea that these
reefs were produced by the subsidence of the ocean bed and the
steady building up of the coral insects toward the surface. He
himself admits that this theory was the most deductive of all that
he ever urged and the least founded in the beginning upon a wide
and careful investigation of fact. Alexander Agassiz, who, after
extensive research, was not disposed to accept it, wrote: ‘Darwin’s
observations were all theoretical, based upon chartographic study
in his house, a very poor way of doing, and that’s the way all his
coral reef work has been done.’[359] And the theory has met with
strenuous opposition from many quarters, though one critic says in
regard to it: ‘Be it true or not, be it a competent explanation or
not, no matter. In influence on geology it has been as far-reaching
as the doctrine of natural selection has been on biology.’[360]
But Darwin himself clung to it to the end, meeting objections with
vast ingenuity and reiterating his positions with ampler and more
penetrating arguments. Yet through all the persistence there is the
readiness at any moment to see the other side. ‘I must still adhere
to my opinion, that the atolls and barrier reefs in the middle of
the Pacific and Indian Oceans indicate subsidence, but I fully agree
with you that such cases as that of the Pellew Islands, if of at all
frequent occurrence, would make my general conclusions of very little
value. Future observers must decide between us.’[361] And he writes
frankly to Alexander Agassiz: ‘If I am wrong, the sooner I am knocked
on the head and annihilated so much the better.’[362]
Another instance of Darwin’s zeal and ingenuity in reasoning is the
theory of sexual selection, devised to meet some difficulties in
his general argument. Many animals have certain so-called secondary
sexual characteristics, that is, characteristics affecting one sex
only yet not directly involved in the reproductive process. Darwin
believed that these characteristics were largely developed through
the working of natural selection upon the basis of the preference of
one sex for individuals of the other for mating purposes. That is to
say, the splendor of the male peacock’s tail made him more attractive
to the female and therefore more successful with her. There were
numerous and obvious difficulties in this view, as the assumption of
a fine æsthetic sense in comparatively lowly organized creatures,
and it was energetically disputed from the start. Wallace, Darwin’s
ardent fellow-thinker and coadjutor, was anything but favorable to
it. Yet Darwin’s faith was never really shaken. He persisted to the
end, making new experiments and investigations, and meeting his
adversaries’ contentions with vast and varied resource. In ‘The
Descent of Man’ he wrote: ‘For my own part I conclude that of all
the causes which have led to the differences in external appearance
between the races of man, and to a certain extent between man and the
lower animals, sexual selection has been the most efficient.’[363]
Nevertheless, it is fascinating to see him reveal the doubt and the
questioning that were inwrought with conviction in his mind. He
writes to Wallace: ‘I grieve to differ from you, and it actually
terrifies me and makes me constantly distrust myself.’[364] Again:
‘You will be pleased to hear that I am undergoing severe distress
about protection and sexual selection; this morning I oscillated
with joy towards you; this evening I have swung back to my [old]
position, out of which I fear I shall never get.’[365] And he sums up
the process with a general remark of the largest and most fruitful
bearing: ‘I sometimes marvel how truth progresses, so difficult
is it for one man to convince another, unless his mind is vacant.
Nevertheless, I myself to a certain extent contradict my own remark,
for I believe far more in the importance of protection than I did
before reading your articles.’[366]
Still another example of theorizing is the doctrine of pangenesis.
Darwin’s general theory of evolution which dealt so much with
heredity, was closely complicated with the difficulty of
understanding how one minute reproductive cell could transmit by
inheritance all the complicated variety of organs and functions in a
highly developed plant or animal. To meet this difficulty he devised
the explanation of pangenesis (he doubts about the name, because ‘my
wife says it sounds wicked, like pantheism’),[367] that is, the idea
that the primitive cell contains a great number of _gemmules_, each
transmitting and originating some particular organ with its varied
functions. Here again the theory, as Darwin conceived it, did not
find general acceptance, though in some respects it surprisingly
anticipates the results of the latest modern research. But the
interesting thing is to see the ardor with which its inventor worked
it out and the elaborate argument with which he carries it through
the latter part of the great work on ‘Animals and Plants under
Domestication.’ It is difficult, he admits. He does not blame any
one for disputing it, or for rejecting it, or even for laughing at
it. ‘The hypothesis of Pangenesis, as applied to the several great
classes of facts just discussed, no doubt is extremely complex, but
so are the facts.’[368] And then he lets his imagination range
more widely than usual in contemplating possible deductions and
consequences: ‘No other attempt, as far as I am aware, has been
made, imperfect as this confessedly is, to connect under one point
of view these several grand classes of facts. An organic being is a
microcosm—a little universe, formed of a host of self-propagating
organisms, inconceivably minute and numerous as the stars in
heaven.’[369] Yet here again he introduces the inevitable reservation
and in his Autobiographical Sketch he says: ‘Towards the end of the
work I give my well-abused hypothesis of Pangenesis. An unverified
hypothesis is of little or no value; but if any one should hereafter
be led to make observations by which some such hypothesis could be
established, I shall have done good service.’[370]
It seems sometimes surprising that, with this marked bent towards
abstract speculation, which it was so difficult to control, Darwin
should have been always so indifferent to philosophical thought
on the ultimate questions of the universe. He admits that he knew
little of metaphysics and cared little for them. But this again is
instructive as to the peculiar balance of his temperament. He liked
to speculate, but he would not speculate for a moment without a
firm foundation of fact. His feet must be based first on the solid
tangible earth. Then if his head would not reach the clouds, he would
keep out of them.
IV
It will be profitable to consider more in detail some specific
elements of Darwin’s reasoning. In the first place, we have seen
everywhere and in all connections that his propensity to eager
theorizing was tempered with an unfailing sense of doubt and
mistrust. He was indeed always disposed to act in the spirit of
Weisman’s remark: ‘When we are confronted with facts which we see
no possibility of understanding save on a single hypothesis, even
though it be an undemonstratable one, we are naturally led to accept
the hypothesis, at least until a better one can be found.’[371]
And he recognized fully the force of the comment which Huxley
makes on a phrase of Goethe, to the effect that doubt must not be
blighting or destructive, but fruitful and stimulating: ‘Goethe has
an excellent aphorism defining that state of mind which he calls
“_Thätige Skepsis_”—active doubt. It is doubt which so loves truth
that it neither dares rest in doubting nor extinguish itself by
unjustified belief.’[64] At the same time, the doubt was there,
was temperamental, and could not be altogether extinguished, even
when the rush of the logical impetus was fullest. One beautiful
expression of it among many is, ‘When you say you cannot master the
train of thoughts, I know well enough that they are too doubtful and
obscure to be mastered. I have often experienced what you call the
humiliating feeling of getting more and more involved in doubt the
more one thinks of the facts and reasoning on doubtful points.’[65]
The truth is, that Darwin had in a high degree the quality, often
so hampering to the man of practical action, but invaluable to the
thinker, of getting outside of himself and his own point of view and
criticizing it as if it were the standpoint of some one else. He
himself indicates this forcibly in connection with returning to one’s
ideas after an interval: ‘The delay in this case, as with all my
other books, has been a great advantage to me; for a man after a long
interval can criticize his own work, almost as well as if it were
that of another person.’[66] Some men can.
Another characteristic of Darwin’s mental processes is his way
of meeting difficulties. The born reasoner is apt to slur over
obstacles and objections, to devote himself with endless ingenuity
to eliminating them rather than facing them squarely. Darwin was
ingenious enough, but he did not dodge difficulties. Instead of doing
so, his propensity was, if anything, to make them and seek them. It
was said of Pasteur, so like Darwin in many points: ‘No adversary
of M. Pasteur had formulated this argument; but M. Pasteur, who
had within himself an ever-present adversary, always on the watch
and determined to yield only to the force of accumulated evidence,
himself raised the objection.’[67] So Darwin. As he himself records,
and no thinker ever laid down a more significant principle or one
more revealing for his own mental constitution: ‘I had, also, during
many years followed a golden rule, namely, that whenever a published
fact, a new observation or thought came across me, which was opposed
to my general results, to make a memorandum of it without fail and
at once; for I had found by experience that such facts and thoughts
were far more apt to escape from the memory than favorable ones.’[68]
And the intense consciousness of objections and difficulties appears
even more vividly in the sentence: ‘I cannot too strongly express my
conviction of the general truth of my doctrines, and God knows I have
never shirked a difficulty.’[69]
The recognition of obstacles and complications constantly popping
up from everywhere naturally necessitated endless revision and
recasting. Here again, the habitual reasoner, having once set his
mould is reluctant to alter it. Not so Darwin. There are indeed
times when even he rebels and declares that it will be more fruitful
to follow new paths than to be perpetually adjusting the old. But
in general his readiness to alter and reconstruct is unlimited.
He revises and works over his books. In doing so he showed his
characteristic disposition to accept and defer to the judgment of
others. How charming is his daughter’s account of this: ‘He was
always so ready to be convinced that any suggested alteration was an
improvement, and so full of gratitude for the trouble taken. I do
not think that he ever used to forget to tell me what improvement
he thought that I had made, and he used almost to excuse himself if
he did not agree with any correction. I think I felt the singular
modesty and graciousness of his nature through thus working for
him in a way I never should otherwise have done.’[70] There is no
better way to appreciate the extent and the persistence of Darwin’s
revision than to make even a cursory comparison of the first and the
last editions of the ‘Origin.’ Almost every page shows minor or
considerable changes, and while some are no doubt mere matters of
language, many have a bearing, however slight, on the trend of the
reasoning, deepening, or strengthening, or clarifying it.
It is profitable also to watch Darwin’s attitude towards argument,
the direct interchange of view by those who take different sides
of a case and are at once eager to advance their own and to detect
the flaws in their opponent’s. It is very evident that he was not a
quick and natural arguer, as was Huxley, for instance. His son says:
‘He used to say of himself that he was not quick enough to hold an
argument with any one, and I think this was true. Unless it was a
subject on which he was just then at work, he could not get the
train of argument into working order quickly enough.’[71] And Darwin
confesses the same thing with his unfailing, charming naïveté, in a
letter to Hooker: ‘I am astonished at your success and audacity. It
is something unintelligible to me how any one can argue in public
like orators do. I had no idea you had this power.’[72]
Arguments haunted him, agitated him, disturbed him. Active discussion
was apt to be followed by a broken night, filled with the things that
might and should have been said and were not. Even of a conversation
quite remote from his scientific interest he says: ‘Your slave
discussion disturbed me much; but as you would care no more for my
opinion on this head than for the ashes of this letter, I will say
nothing except that it gave me some sleepless, most uncomfortable
hours.’[73]
The gift I have before suggested, of getting outside of your own
position and judging it as another would, while it benefits the
results of argument, is most hampering in the process, since one
finds oneself stating one’s adversary’s case sometimes more forcibly
than he does himself. Darwin often repeats the principle I have
quoted earlier, of recognizing and recording objections, and he sums
up his method in regard to his main theory: ‘I have for some time
determined to give the arguments on _both_ sides (as far as I could)
instead of arguing on the mutability side alone.’[74]
Yet in spite of all the strain and effort of argument, he liked it
and believed in it. In the concluding chapter of the ‘Origin’ he
says: ‘This whole volume is one long argument.’[75] It certainly is.
Elsewhere he says of a personal conversation: ‘I was particularly
glad of our discussion after dinner; fighting a battle with you
always clears my mind wonderfully.’[76] To get the mind clear, to
illuminate and elucidate the complicated tangles of thought and
theory, that was always the object, and if verbal battles helped it
on, they were welcome.
But if he liked sincere, earnest argument, he detested controversy,
the bitter war of excited personal feelings bent rather on achieving
an individual triumph than on proving an abstract theory. He
condemned and deplored the injury to science inevitably wrought by
such disputes and had nothing but disgust for the manifestations of
temper that were bound to accompany them: ‘I went the other evening
to the Zoölogical Society, where the speakers were snarling at each
other in a manner anything but like that of gentlemen.’[77]
When his own views were involved in bitterness, as, alas, they too
often were, he expressed the keenest regret: ‘I often think that my
friends ... have good cause to hate me, for having stirred up so much
mud, and led them into so much odious trouble. If I had been a friend
of myself, I should have hated me.’[78] He early made up his mind to
keep out of quarrels if possible, and he congratulated himself on the
whole on his success: ‘I rejoice that I have avoided controversies,
and this I owe to Lyell, who many years ago, in reference to my
geological works, strongly advised me never to get entangled in a
controversy, as it rarely did any good and caused a miserable loss of
time and temper.’[79]
Thus, whenever it was possible, he shunned dispute, and if, by any
chance, haste and eagerness involved him in a mistaken cause, he
bitterly regretted his blunder and was ready to acknowledge it with
the utmost frankness. One of the most striking cases of this is that
of the parallel roads of Glen Roy, as to which Darwin had developed a
geological theory which he asserted with a good deal of conviction.
A careful consideration of his opponent’s arguments, obliged him to
recognize that he was completely in the wrong, and he gave up, though
with a pang: ‘I am very poorly to-day, and very stupid, and hate
everybody and everything. One lives only to make blunders.’[80] His
acknowledgment of his error was ample and complete.
It was his natural frankness in admitting his mistakes and
endeavoring to rectify them which made Darwin so attractive and
engaging. Goethe complains of the disposition of many people to
reiterate a misstatement because they have once made it.[81] Such
reiteration did not appeal to Darwin in the least. Sometimes he was
irritated and annoyed by the attitude of his adversaries, and he
expressed the annoyance with the same outspokenness that he gave to
other things; but there was never any attempt to conceal his blunders
or to maintain his own positions simply because they were his.
Indeed, in this regard, as in all others, what distinguished him was
a singular and charming candor. It is this which makes his letters
so attractive and so revealing. They are not great literary letters.
They are always written in haphazard fashion and with the utmost
casual directness. But few correspondences of literary men or of any
others reveal the man with such clear and winning amplitude. He opens
his heart and leads you right into it without the least pretence of
self-revelation, but simply as if he were thinking aloud to you, as
he is. Take, for instance, among a bewildering mass of illustrations,
his confession of the sense of inferiority in regard to Spencer: ‘I
feel rather mean when I read him: I could bear, rather enjoy feeling
that he was twice as ingenious and clever as myself, but when I feel
that he is about a dozen times my superior, even in the master art
of wriggling, I feel aggrieved.’[82] Or this other acknowledgment
to Hooker: ‘How candidly and meekly you took my Jeremiad on your
severity to second-class men. After I had sent it off, an ugly little
voice asked me, once or twice, how much of my noble defence of the
poor in spirit and in fact, was owing to your having not seldom
smashed favorite notions of my own. I silenced the ugly little voice
with contempt, but it would whisper again and again.’[83] The sense,
the atmosphere, of a pervading candor, was what Huxley expressed so
excellently when he spoke of Darwin’s having ‘a certain intense and
almost passionate honesty by which all his thoughts and actions were
irradiated, as by a central fire. It was this greatest and rarest of
endowments which kept his vivid imagination and great speculative
powers within due bounds ... which made him accept criticisms and
suggestions from anybody and everybody, not only without impatience,
but with expressions of gratitude sometimes almost comically in
excess of their value.’[84]
For the honesty and the candor not only led him to admit his own
mistakes, but made him singularly ready to recognize the merits of
others, and to tolerate not only their views but even their dogmatic
assertion of them. He made mistakes all the time, and yet he knew
that he was sincere and lofty in purpose. Why should not others be
the same? Why should not their theories be right and his wrong? ‘It
matters very little to any one except myself, whether I am a little
more or less wrong on this or that point; in fact, I am sure to be
proved wrong on many points.’[85] Of one who did not agree with him
he could say: ‘I know nothing of him excepting from his letters:
these show remarkable talent, astonishing perseverance, much modesty,
and what I admire, determined difference from me on many points.’[86]
And how winning is his defense of blunderers, of those who do poor
work which is not all poor: ‘Shall you think me very impudent if I
tell you that I have sometimes thought that ... you are a little
too hard on bad observers; that a remark made by a bad observer
_cannot_ be right; an observer who deserves to be damned you would
utterly damn. I feel entire deference to any remark you make out of
your own head; but when in opposition to some poor devil, I somehow
involuntarily feel not quite so much.’[87]
The truth is, that Darwin’s tolerance was based, as all real
tolerance is apt to be, on the vast and haunting sense of his own
ignorance. Again and again he repeats and emphasizes how little
he knows, how little any one knows, and how petty, imperfect, and
inadequate are the efforts of any and all of us to penetrate the
veil of shrouding mystery which involves the deepest secrets of
life. To probe this mystery the vague and flickering torch of reason
is all that is given to us. And those who are most conversant with
reason and make most use of it mistrust it most. When the far surer
guidance of instinct fails us, reason is our only support, and we
must employ it not only for the larger speculative purposes, but for
the practical decisions. At its best, it is a bright and splendid
instrument, incredibly keen and penetrating, and able to accomplish
miracles in the hands of those who manipulate it skillfully. But it
is an instrument as delicate as it is bright, and it loses point
and edge, unless constant pains are taken to keep it in working
condition. Also, it cuts both ways, and every way, and to even the
expert manipulator, perhaps to him most of all, it is apt to be
difficult, dangerous, treacherous.
There is the subtle, unfathomable connection of reason with our
wishes, desires, and prejudices. A clever Frenchman said that reason
was given us to enable us to justify the gratification of our
passions, and when we see how the devices of logic may be used to
work from any premises to any conclusion, one feels the force of the
Frenchman’s view.
No one was more aware than Darwin of these dangers and difficulties
of reason, or of the endless possibilities of deception when one
gives oneself up to that enchanting and deluding siren. He often
emphasizes his distress and almost despair at finding himself making
deductions quite different from those which others draw from the
same facts. ‘It is really disgusting and humiliating to see directly
opposite conclusions drawn from the same facts.’[88] And again:
‘Nothing is so vexatious to me, as so constantly finding myself
drawing different conclusions from better judges than myself, from
the same facts.’[89] And yet again: ‘I hate beyond all things finding
myself in disagreement with any capable judge, when the premises are
the same.’[90]
These comments make us see clearly what Darwin’s relation to reason
was. Few thinkers have been so ready, so fertile, so abundant,
so ingenious, yet at the same time so sober, so restrained and
controlled.
With this analysis of his observation and his thought we are ready
to take up the supreme interest of Darwin’s life, the dramatic study
of the conception, elaboration, promulgation, and triumph of his
evolutionary theory.