第 31 节
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as an attempt at serious answer; for the perfunctory and illusory
remarks of Mr。 Wallace at the end of his 〃Darwinism〃 cannot be
counted as such。 The best proof of its irresistible weight is that
Mr。 Darwin; though maintaining silence in respect to it; retreated
from his original position in the direction that would most obviate
Mr。 Spencer's objection。
Yet this objection has been repeatedly urged by the more prominent
anti…Charles…Darwinian authorities; and there is no sign that the
British public is becoming less rigorous in requiring people either
to reply to objections repeatedly urged by men of even moderate
weight; or to let judgment go by default。 As regards Mr。 Darwin's
claim to the theory of evolution generally; Darwinians are beginning
now to perceive that this cannot be admitted; and either say with
some hardihood that Mr。 Darwin never claimed it; or after a few
saving clauses to the effect that this theory refers only to the
particular means by which evolution has been brought about; imply
forthwith thereafter none the less that evolution is Mr。 Darwin's
theory。 Mr。 Wallace has done this repeatedly in his recent
〃Darwinism。〃 Indeed; I should be by no means sure that on the first
page of his preface; in the passage about 〃Darwin's theory;〃 which I
have already somewhat severely criticised; he was not intending
evolution by 〃Darwin's theory;〃 if in his preceding paragraph he had
not so clearly shown that he knew evolution to be a theory of
greatly older date than Mr。 Darwin's。
The history of sciencewell exemplified by that of the development
theoryis the history of eminent men who have fought against light
and have been worsted。 The tenacity with which Darwinians stick to
their accumulation of fortuitous variations is on a par with the
like tenacity shown by the illustrious Cuvier; who did his best to
crush evolution altogether。 It always has been thus; and always
will be; nor is it desirable in the interests of Truth herself that
it should be otherwise。 Truth is like moneylightly come; lightly
go; and if she cannot hold her own against even gross
misrepresentation; she is herself not worth holding。
Misrepresentation in the long run makes Truth as much as it mars
her; hence our law courts do not think it desirable that pleaders
should speak their bona fide opinions; much less that they should
profess to do so。 Rather let each side hoodwink judge and jury as
best it can; and let truth flash out from collision of defence and
accusation。 When either side will not collide; it is an axiom of
controversy that it desires to prevent the truth from being
elicited。
Let us now note the courses forced upon biologists by the
difficulties of Mr。 Darwin's distinctive feature。 Mr。 Darwin and
Mr。 Wallace; as is well known; brought the feature forward
simultaneously and independently of one another; but Mr。 Wallace
always believed in it more firmly than Mr。 Darwin did。 Mr。 Darwin
as a young man did not believe in it。 He wrote before 1889;
〃Nature; by making habit omnipotent and its effects hereditary; has
fitted the Fuegian for the climate and productions of his country;〃
{21} a sentence than which nothing can coincide more fully with the
older view that use and disuse were the main purveyors of
variations; or conflict more fatally with his own subsequent
distinctive feature。 Moreover; as I showed in my last work on
evolution; {22} in the peroration to his 〃Origin of Species;〃 he
discarded his accidental variations altogether; and fell back on the
older theory; so that the body of the 〃Origin of Species〃 supports
one theory; and the peroration another that differs from it toto
caelo。 Finally; in his later editions; he retreated indefinitely
from his original position; edging always more and more continually
towards the theory of his grandfather and Lamarck。 These facts
convince me that he was at no time a thorough…going Darwinian; but
was throughout an unconscious Lamarckian; though ever anxious to
conceal the fact alike from himself and from his readers。
Not so with Mr。 Wallace; who was both more outspoken in the first
instance; and who has persevered along the path of Wallaceism just
as Mr。 Darwin with greater sagacity was ever on the retreat from
Darwinism。 Mr。 Wallace's profounder faith led him in the outset to
place his theory in fuller daylight than Mr。 Darwin was inclined to
do。 Mr。 Darwin just waved Lamarck aside; and said as little about
him as he could; while in his earlier editions Erasmus Darwin and
Buffon were not so much as named。 Mr。 Wallace; on the contrary; at
once raised the Lamarckian spectre; and declared it exorcised。 He
said the Lamarckian hypothesis was 〃quite unnecessary。〃 The giraffe
did not 〃acquire its long neck by desiring to reach the foliage of
the more lofty shrubs; and constantly stretching its neck for this
purpose; but because any varieties which occurred among its
antitypes with a longer neck than usual at once secured a fresh
range of pasture over the same ground as their shorter…necked
companions; and on the first scarcity of food were thus enabled to
outlive them。〃 {23}
〃Which occurred〃 is evidently 〃which happened to occur〃 by some
chance or accident unconnected with use and disuse。 The word
〃accident〃 is never used; but Mr。 Wallace must be credited with this
instance of a desire to give his readers a chance of perceiving that
according to his distinctive feature evolution is an affair of luck;
rather than of cunning。 Whether his readers actually did understand
this as clearly as Mr。 Wallace doubtless desired that they should;
and whether greater development at this point would not have helped
them to fuller apprehension; we need not now inquire。 What was
gained in distinctness might have been lost in distinctiveness; and
after all he did technically put us upon our guard。
Nevertheless he too at a pinch takes refuge in Lamarckism。 In
relation to the manner in which the eyes of soles; turbots; and
other flat…fish travel round the head so as to become in the end
unsymmetrically placed; he says:…
〃The eyes of these fish are curiously distorted in order that both
eyes may be upon the upper side; where alone they would be of any
use。 。 。 。 Now if we suppose this process; which in the young is
completed in a few days or weeks; to have been spread over thousands
of generations during the development of these fish; those usually
surviving WHOSE EYES RETAINED MORE AND MORE OF THE POSITION INTO
WHICH THE YOUNG FISH TRIED TO TWIST THEM 'italics mine'; the change
becomes intelligible。〃 {24} When it was said by Professor Ray
Lankesterwho knows as well as most people what Lamarck taught
that this was 〃flat Lamarckism;〃 Mr。 Wallace rejoined that it was
the survival of the modified individuals that did it all; not the
efforts of the young fish to twist their eyes; and the transmission
to descendants of the effects of those efforts。 But this; as I said
in my book; 〃Evolution; Old and New;〃 {25} is like saying that
horses are swift runners; not by reason of the causes; whatever they
were; that occasioned the direct line of their progenitors to vary
towards ever greater and greater swiftness; but because their more
slow…going uncles and aunts go away。 Plain people will prefer to
say that the main cause of any accumulation of favourable
modifications consists rather in that which brings about the initial
variations; and in the fact that these can be inherited at all; than
in the fact that the unmodified individuals were not successful。
People do not become rich because the poor in large numbers go away;
but because they have been lucky; or provident; or more commonly
both。 If they would keep their wealth when they have made it they
must exclude luck thenceforth to the utmost of their power; and
their children must follow their example; or they will soon lose
their money。 The fact that the weaker go to the wall does not bring
about the greater strength of the stronger; it is the consequence of
this last and not the causeunless; indeed; it be contended that a
knowledge that the weak go to the wall stimulates the strong to
exertions which they would not otherwise so make; and that these
exertions produce inheritable modifications。 Even in this case;
however; it would be the exertions; or use and disuse; that would be
the main agents in the modification。 But it is not often that Mr。
Wallace thus backslides。 His present position is that acquired (as
distinguished from congenital) modifications are not inherited at
all。 He does not indeed put his faith prominently forward and pin
himself to it as plainly as could be wished; but under the heading;
〃The Non…Heredity of Acquired Characters;〃 he writes as follows on
p。 440 of his recent work in reference to Professor Weismann's
Theory of Heredity:…
〃Certain observations on the embryology of the lower animals are
held to afford direct proof of this theory of heredity; but they are
too technical to be made clear to ordinary readers。 A logical
result of the theory is the impossibility of the transmission of
acquired characters; since the molecular structure of the germ…plasm
is already determined with