(1.) _The Descent of Man and Selection in relation to Sex._ By CHARLES
DARWIN, M.A., F.R.S., &c. 2 vols. John Murray.
(2.) _On the Genesis of Species._ By ST. GEORGE MIVART, F.R.S.
Macmillan.
The mode of the origin of man is a question of such momentous interest
to intelligent men that it is not easy to handle it with calm
philosophical indifference, or to discuss it dispassionately. It is
true, we have been informed that the conclusions concerning man's
evolution which have been lately taught far and wide are not opposed
to religion, but we have not been favoured with the tenets of that
religion to which an evolutionist may, without inconsistency,
subscribe. We have even been assured that evolution presents us with a
most noble view of the Great Creator, who endowed living matter with
the capacity of change, and subjected it to natural laws; that it
admits the necessity of a directing, intelligent will, and refers all
the phenomena of the universe to God. But those who have recorded this
remarkable discovery have not been careful to make known to us the
attributes of that Deity in whom they trust; and they express
themselves in a manner that is rather vague concerning the limits
imposed upon His power, His will, and His government by what they call
natural law.
The hypothesis of evolution, it has been said, does not touch the
question of the origin of life, for evolution is supposed to begin to
operate only after that mysterious, if not miraculous phenomenon has
been completed. Our readers should, however, remember that quite
recently Sir W. Thomson has relegated to a sphere long since
shattered, the birth of the first living spark which peopled this
earth, and thus we are released from the difficulty of framing an
hypothesis to account for the first particle that lived. But a third
class of evolutionists professes to be able to trace the actual origin
of the living from non-living matter, and even maintains that a series
of insensible gradations has been established between the inanimate
and the living.
These are some of the considerations which are agitating men's minds
in the days in which we live; and Mr. Darwin, in his last work, has
clearly defined the conclusions concerning man's origin which, as he
maintains, we are compelled by the facts of nature to accept, though
he does not indicate, and indeed seems supremely unconscious of the
tremendous nature of the issues raised by his philosophic teaching. 'I
am aware,' says Mr. Darwin, 'that the conclusions arrived at in this
work will be denounced by some as highly irreligious;' but he himself
has failed to discover anything irreligious in the view he has taken.
It is, however, very difficult to form a correct estimate of this
opinion in the absence of any explanation of the meaning which Mr.
Darwin attaches to the terms, religion and irreligion. The religious
views of those who regard man as a being distinct and altogether apart
from brute animals must needs be different from the religious views of
those who look upon him as a mere animal, though it is possible that
the latter conclusion may not conflict with religious beliefs of some
kind or other.
We should not have ventured to offer these remarks upon the religious
aspect of the question had it not been adverted to, and, as we think,
quite unnecessarily, by Mr. Darwin himself; our main object in this
article being to consider the scientific question from the scientific
side.
That man began to be in a very remote past is now freely admitted by
all; but this is perhaps the only one of the many propositions
advanced in connection with man's origin that will be accepted by
different authorities who have considered the question from different
points of view.
Not a few persons still accept the ancient tradition, and up to this
very time maintain, that the idea that man sprang as man direct from
the hands of his God remains unshaken, and that the evidence advanced
in favour of more recent interferences is not only incomplete, but
vague, fragmentary, uncertain, and unconvincing. But while it must be
admitted that the majority of scientific men who have studied the
subject are agreed in the conclusion, that science can point to no
fact at all conclusive in favour of the idea of the direct creation of
man from the dust of the ground, it is by no means so certain that the
scientific evidence advanced in favour of very different inferences is
more convincing, or as worthy of acceptance as their enthusiastic
advocates would have us believe. It cannot be too often clearly stated
that the whole spirit of science demands that scientific conclusions
should rest upon the evidence of facts, and upon facts alone. Evidence
advanced by the scientific observer must be evidence which can be
adduced over and over again; evidence which will bear to be examined
and re-examined in its minutest particulars and with the utmost care.
Nothing is to be taken on trust by the man who would advance real
knowledge, and he who endeavours to convince an audience of the truth
of some new scientific conjecture, by telling it that no other
explanation can be advanced than the particular one that he offers, is
true neither to science nor to himself. It is his business to produce
evidence, not to try to force his own conviction on other minds, and
he should most scrupulously avoid phrases which partake more of the
character of threats than arguments. 'Accept this view, or I shall
regard you as unreasonable, and consider you a savage,' is the
language of a member of an intellectual prize-ring rather than that of
a calm, dispassionate investigator of nature, searching after the
truth for truth's sake.
Into recent discussions concerning the origin of man, much extraneous
matter has been imported, and in many articles acrimonious remarks
have unfortunately been introduced for which little excuse can be
offered; but it appears to us impossible to deny that the conclusion
we arrive at concerning the origin of man may, and probably must
seriously affect our views concerning the nature of our relation to
Deity, and our belief in a future state; but it is surely premature to
allow our convictions to be greatly disturbed by such considerations,
for it is doubtful whether we are yet in possession of sufficient
knowledge to enable us to deduce any definite conclusion upon this
most difficult question. Men who call themselves philosophical and
scientific may laugh at what they call the legends concerning man's
origin, which are received as truths by the unscientific; but much
will have to be added to the evidence already existing in favour of
the arboreal habits of our ancestors, before the notion will be
generally accepted as worthy of serious belief, or as entirely free
from ludicrousness. The reader of science in these days must be
careful not to mistake conjectural propositions, however ingeniously
expressed, for established scientific demonstrations.
Our acceptance or rejection of Mr. Darwin's views regarding the
descent of _man_ will be mainly determined by the conclusions we have
been led to adopt concerning his doctrine of the formation of
different species of animals by natural selection. The writer of this
article, disagreeing, as he does, entirely, with the views adopted by
Mr. Darwin's opponents, would be quite ready to concede the doctrine
of the descent of man from a lower form if he felt convinced that the
evidence adduced was sufficient to prove that even a few of the lower
animals and plants had resulted by development from lower forms. He is
well aware that, both here and on the Continent, many scientific
authorities accept the doctrine of natural selection as applied to
plants and animals, but hold that as regards man the evidence, is
altogether inconclusive. Mr. Darwin evidently wishes his readers to
accept upon faith the dictum that it has really been positively
demonstrated that all species of the inferior animals have been
evolved from some lower beings, for he uses this as an inferential
argument in favour of the doctrine that man, '_like every other
species_,' has descended from pre-existing forms.
We shall not therefore argue, as has often been done, that although
natural selection may be true as applied to animals, it is not correct
as regards man, but shall concede this point, and admit that, if it
could be proved that dissimilar animals had descended from a common
progenitor, we might believe that man's body has been formed in the
same way. But we dispute the evidence hitherto advanced to prove that
even plants as much alike or unlike as the rose and the thistle have
descended from a common plant; and we doubt if sufficient time has
elapsed for effecting the requisite changes in the very gradual manner
in which the hypothesis assumes that they have occurred.
A great array of facts are marshalled before the reader, in order to
produce the impression that the foregone conclusion really rests upon
a very firm foundation; but it is remarkable how frequently
hypothetical inferences are made to do duty for inductive arguments.
Thus Mr. Darwin assumes that because man, like the lower animals, is
subject to malconformations, arrested development, or reduplication of
parts, his origin _must have been_ like theirs. It is, however,
obvious that such an argument begs the question at issue. It is
clearly possible that man's body might agree with the bodies of the
lower animals in these and many other points, and yet be formed upon
altogether different principles; while man and animals might be alike
in these points, without either having been derived as Mr. Darwin
supposes. Again, it seemed scarcely necessary to repeat the
affirmation that there was much in common between the bodily structure
of man and animals, because everyone who has studied the matter ever
so carelessly freely admits that there is, and every child would
acknowledge the fact from his own observation. What Mr. Darwin desires
us to believe is, that this similarity in structure is due to
community of origin; but this is a very different thing. The fact must
be accepted, but the proposed explanation of the fact is, after all,
only an assertion. It has been audaciously said that Mr. Darwin's
explanation ought to be accepted as true if no more probable
explanation be advanced; but surely this is to mistake altogether the
object of scientific inquiry; for it by no means follows that an
improbable hypothesis ought to be accepted and taught as true, because
its opponents are unable or unwilling to propose a new hypothesis
several degrees less improbable. The question for us to determine, is
simply how far the arguments advanced by Mr. Darwin justify the
conclusion at which he has arrived; and it is not good reasoning to
argue that, because the bodily structure of man resembles that of
animals, and the bodily structures of animals resemble one another,
therefore all have community of origin; for it is clear that there may
be some very different explanation of these facts which cannot be
discovered, nor will be until we possess more knowledge of them. We
may accept as a fact the well known general resemblance between the
tissues of different animals and the tissues of man and animals, but
we may deny that this resemblance is sufficiently close to ground upon
it the doctrine that all tissues have been derived from a common
ancestral tissue-forming substance. We quite agree with Mr. Darwin,
that 'man is constructed on the same general type or model with other
mammals,' but we fail to see in this an argument for the doctrine that
he and they have a common origin.
If, however, the tissues, blood, and secretions of man were like those
of animals, that is, if they could not be distinguished from the
latter in ultimate structure and chemical composition and properties,
we should be quite ready to accept Mr. Darwin's conclusion; and not a
few of Mr. Darwin's readers will imagine that such is really the case,
for the language employed almost implies that a very exact likeness
has been proved to exist. Mr. Darwin has, however, been careful so to
express himself as to lead his readers to adopt the inference he
desires, without laying himself open to the charge of undue
persuasion, while professing only to be laying facts before their
unbiassed judgment. In truth, such enthusiasm has been stirred up in
favour of Mr. Darwin's doctrines that the task of criticism has become
unpleasant, and it requires some courage even to offer a hint that
after all they _may_ not turn out to be true. And yet it is not
possible for anyone who has studied anatomical structure to assent to
many of the statements in the very first chapter of Mr. Darwin's book.
As regards bodily structure and chemical composition, and also minute
structure of tissues, there are points of difference between man and
animals more striking and remarkable than the points in which
resemblance may be traced. So, too, with reference to embryonic
development, resemblance increases the further we go back, and much
more may be proved than Mr. Darwin requires for the support of his
hypothesis. An embryo man is not more like an embryo ape than either
is like an embryo fish. The mode of origin and the development of
every tissue in nature are indeed alike in many particulars, but this
fact, so far from being an argument in favour of the common parentage
of any or all, seems to indicate that all are formed according to some
general law, which nevertheless permits the most remarkable
variations, not solely dependent upon either external conditions or
internal powers.
It has been shown that certain structural characteristics observable
to the unaided eye are common to man and the lower animals, and this
fact has been urged in favour of the conclusion adopted by Mr.
Darwin. Thus, great stress is laid upon the presence of 'the little
blunt point projecting from the inwardly folded margin or helix of the
ear of man.' This is decided to be the vestige of the formerly pointed
ears of the progenitors of our predecessors with arboreal habits, but
nothing is said in explanation of the complete absence of rudiments of
parts which we should expect to find. And surely there may be
differences of opinion as to the bearing of many of the facts
advanced, although Mr. Darwin affirms that their bearing is
unmistakable. The observation that, 'on any other view, the similarity
of pattern between the hand of a man or monkey, the foot of a horse,
the flipper of a seal, the wing of a bat, &c., is utterly
inexplicable,' is not complimentary to the ingenuity or conjectural
capacity of those who are to succeed Mr. Darwin; but to assert that
these parts have been formed on the same ideal plan is not a
scientific explanation; it is merely to express an opinion in a very
arbitrary and rather abrupt manner. It may be 'natural prejudice' and
it may be 'arrogance' which leads some to demur to the conclusions
deduced by Mr. Darwin and his friends, and the prophecy[63] at the end
of his chapter may be fulfilled, but it is at any rate premature;
while it is by no means fair to imply that every naturalist who
refuses to accept Mr. Darwin's hypothesis believes that each mammal
and man 'was the work of a separate act of creation.'
As is well known, there are certain diseases which may be communicated
from man to the lower animals, or from the lower animals to man, and
Mr. Darwin tells us that the fact 'proves (!) the close similarity of
their tissues and blood, both in minute structure and composition.'
Here, again, in what he regards as his proof, Mr. Darwin begs the
question. Such premises afford no justification whatever for the
conclusion arrived at, while the force of the remark depends entirely
upon the meaning attached to the phrase 'close similarity.' We may
assert with truth that there is a _very close similarity_ between the
blood of a rat and the blood of a Guinea pig, and also that the blood
of the rat _differs widely_ from that of the Guinea pig. In the first
assertion, 'close similarity' is used in a sense which does not imply
that 'widely different' is not equally true of the statement to which
it relates. The argument adopted by Mr. Darwin is not an argument in
favour of his conclusion. He might urge with equal force that since
bacteria grow and multiply in many different fluids and solids, these
fluids and solids exhibit a close similarity in structure and
composition; or, conversely, it might be held, that because certain
poisons produce very different effects upon the nerve-tissues of
different animals, therefore the nerve-tissues of these animals must
differ widely in minute structure and chemical composition.
As regards the statements that man and animals alike die of apoplexy,
suffer from fever, are subject to cataract, take tea, are fond of
tobacco, and the like, it is simply astounding that Mr. Darwin should
have advanced them with the view of strengthening his case. The
circumstance almost leads us to infer that he was not altogether
unconscious of the weakness of his own cause. He has been
over-sanguine regarding his powers of convincing his readers of the
truth of any proposition he might think fit to advance. It would have
been more to the purpose to have maintained that, since all mammals
have blood and blood-vessels, brains, and nerves, it is certain that
all mammals must have had a common origin, since it is not possible to
account for the close similarity between these tissues in any other
way.
Nor is it easy to understand how the community-of-origin hypothesis is
assisted by the fact that man and animals are infested by parasites,
seeing that the parasites are as different from one another as are the
species which they infest, and, like the latter, are incapable of
interbreeding, and exhibit specific distinctions of the most striking
kind.
That reproduction and gestation are carried out upon the same general
plan in all mammals is universally known, but it is straining argument
with a vengeance to advance this in favour of their community of
origin, considering the marvellous variations in detail which are
observed in respect of these processes in different and even in very
closely allied mammals.
The fact that man arrives at maturity more slowly than other animals
is met by Mr. Darwin with the cautious observation that 'the orang _is
believed_ not to be adult till the age of from ten to fifteen years.'
This is by no means a solitary example of the very vague observations
which Mr. Darwin admits as data upon which to ground his conclusions.
For want of more demonstrative evidence, he is constrained to accept
the loose statement to which we have alluded; and it must be admitted
that he has displayed considerable ingenuity in making the most of the
utterly inconclusive and sometimes unreliable material at his
disposal; but it is indeed very remarkable that he should consider
himself in any way justified by the facts and arguments to which he
has adverted, in summing up so very definitely and so very decidedly
as he has done on the sixth page of the first chapter of his book. The
italics in the following sentence are our own: 'It is, in short,
_scarcely possible to exaggerate the close correspondence_ in general
structure, in the minute structure of the tissues, in chemical
composition, and in constitution, between man and the higher animals,
especially the anthropomorphous apes!'
Mr. Darwin adduces another argument in his favor from embryonic
development, and proceeds to show that at a certain period the human
embryo is very like that of the dog. He quotes with approval the
remark of Mr. Huxley, that as regards development man is 'far nearer
to apes than the apes are to the dog;' but if we suppose the
resemblance to be far greater than is really the case, it is difficult
to see how the fact would strengthen the hypothesis in favour of which
it is advanced. Because the embryo of a dog resembles that of a man,
therefore both were derived from a common progenitor, seems a very
curious specimen of reasoning, and implies the acceptance of a number
of other propositions which have been and will continue to be
disputed. We are assured that no other explanation than the one
advanced by Mr. Darwin 'has ever been given of the marvellous fact
that the embryos of a man, dog, seal, bat, reptile, &c., cannot at
first be distinguished from each other;' but as needs scarcely be
said, this circumstance adds no weight to the particular explanation
in question, and does not increase the probability of its being proved
to be true at some future day. According to Mr. Darwin, we _ought_
frankly to admit the force of every argument he thinks fit to advance;
but surely, before doing so, there is no harm in examining the facts a
little more closely. And, first, it would have been desirable to
inquire whether the resemblance was really as great as a superficial
examination by the unaided eye seemed to indicate; next, it should
have been ascertained whether the _differences_ between the animal and
the human embryo were not also very considerable; in which case it
would have been necessary to inquire further concerning the bearing of
the differences demonstrated, upon the hypothesis of the community of
origin of the several embryos, grounded upon the likeness.
But Mr. Darwin does not tell us why he selected one particular period
of development for demonstrating the resemblance between the human
embryo and that of the dog. The likeness was in truth much greater at
a period still earlier than the one selected. Nay, the fact must be
known to Mr. Darwin, that at a very early stage in development we fail
to discover, after the most careful scrutiny, any difference between
the matter which, under certain conditions, will become man, and that
which, under certain other conditions, will become dog, or cat, or
bird, or frog, or jelly-fish, or plant; yet it would be monstrous to
assert that apparent likeness was real identity. It is only during the
later stages of development, as Mr. Huxley affirms, and as has been
well known for fifty years or more, that 'the young human being
presents _marked_ differences from the young ape.' But why is the
reader not told that at a very early period of development these
embryos are not only like one another, but could not by any means at
our disposal be distinguished from each other or from any other form
of embryo matter in nature? The results of the act of living in the
two cases are very different, but the living matter itself seems to be
nearly identical. The material out of which man is evolved is perhaps
exactly like that from which every other vertebrate living being
proceeds, and it does not differ in any ascertained points from that
from which the most destructive morbid growths may be developed. Here,
then, is an argument for the community of origin of everything in
nature. Not only is man's brain developed like the dog's brain, but
the matter in which every one of his organs originates is like that
from which every other tissue in nature is evolved.
But when we come to examine more minutely the tissues of the embryo
man and the embryo dog at about the period of development selected by
Mr. Darwin for comparison, we find very remarkable points of
difference in their minute structure. If we examine particular tissues
by the aid of high microscopic powers, we shall discover points of
difference as well as points in which they agree, and this at every
stage of growth subsequent to the time when the tissues have acquired
their special characters. If, then, from the fact of general
resemblance we are to argue in favour of a common origin, what
explanation have we to offer of the peculiar and constant, though
definite differences between the corresponding tissues of different
animals at corresponding periods of development? Mr. Darwin's
explanation may account for the resemblance between the different
embryos at a particular period of development, but it does not help us
in the least to understand why there should be differences in the
ultimate structure of the tissues at this same period, any more than
it explains the still more remarkable resemblance between different
forms of embryonic matter at every period of life, in health and in
disease.
It is difficult to understand how 'natural selection' can work, unless
we admit that the matter of the germ possesses the property of
undergoing modification. But if modifying power determines the
changes, this must itself be referred to something _inherent_ in the
matter of the germ itself--a primary power of the organism transmitted
from pre-existing organisms. Such a power is, however, inadmissible in
any evolutional hypothesis, and so far from being explained by natural
selection, explains the facts grouped under that head. It is true that
Mr. Darwin does admit the operation of 'unknown agencies' influencing
the nature and constitution of the organism, but he adduces no reason
for supposing that these unknown agencies will be discovered at some
future time, or that they are in any way dependent on natural
selection. If we require 'unknown agencies' at all, we may surely
dispense with natural selection altogether, and attribute the
formation of species to these unknown agencies directly, instead of
attributing it to natural selection and referring natural selection to
the unknown agencies.
It certainly would be an argument of the very highest importance, and
indeed most convincing, if it could be shown that, in their minute
structure, the corresponding tissues of man and animals very closely
agreed. Mr. Darwin affirms that this is indeed the case, and says that
the correspondence in minute structure is so close, especially in the
case of man and the anthropomorphous apes, that it is _impossible to
exaggerate it_. But strange to say, he adduces no evidence whatever in
support of the assertion, although he does not hesitate to make use of
the assumed close correspondence as if it had been demonstrated in the
most unequivocal manner. Mr. Darwin is unquestionably correct in
attaching the very highest importance to this part of the evidence. As
the question of correspondence in the minute structure of tissues
between man and animals has scarcely been touched upon in any of the
numerous critiques which have been written upon Mr. Darwin's
hypothesis, we propose to direct the reader's attention to a few
details of considerable interest, affecting not only the validity of
views concerning, the descent of man, but affecting also the
hypothesis of evolution. It has been already stated that we are ready
to admit the full force of the fact of the close correspondence if
this can be proved; but, on the other hand, if constant differential
characters can be distinctly demonstrated, especially in corresponding
tissues of closely allied species, it must be conceded that the
circumstance will be very damaging to the hypothesis of evolution; for
it is very doubtful if even the very great ingenuity displayed by Mr.
Darwin and his followers would enable them to offer an explanation
which would be considered plausible. It is somewhat significant that
the subject of minute structure, in spite of its great importance
having been freely admitted, has been very lightly touched upon. So
far, evolutionists have fought rather shy of the evidence to be
obtained by a very minute and careful examination of the tissues;
though strongly advocating careful investigations of a general
character, they have been very reticent on the question of microscopic
investigation, and in not a few instances there are indications of an
indisposition to study minute details, as if they feared observation
might be pushed too far, or too much into detail to serve their
purpose. Attention is constantly directed to the general points in
which different species resemble each other, and the reader becomes
fully impressed with the great importance of the argument resting upon
the fact of the strong similarity between man and apes, but no direct
comparison in minute structure between any human and simian tissue is
instituted, nor are any results of such comparisons anywhere referred
to. But if, for example, it could be shown that in their minute
anatomy the tissues of an ape so closely resembled those of a dog on
the one hand, and of a man on the other, as that they could not be
distinguished by the microscope, the fact would be of the highest
importance, and would add enormously to the evidence already adduced
to Mr. Darwin who lays much stress upon the close correspondence
between the tissues of man and animals in minute structure, but never
tells us that such comparison has been actually made by himself or by
others. It is certainly remarkable that a fact which Mr. Darwin
evidently considers of vast importance, and which is capable of being
easily put to the test of observation, should be stated without the
results of a single observation being recorded. Surely an appeal to
actual experiment should have been made in at least a few instances,
which would illustrate not only the close correspondence, but the
absence of differences between corresponding tissues in different
species. This having been done, it should then have been clearly
stated in what manner this correspondence in minute structure favours
the idea of the common origin of distinct species. But Mr. Darwin is
content here, as in many other cases, with asserting the fact as a
fact, and then stating that it helps in an important manner to
establish the truth of the doctrine he advocates.
As this supposed correspondence in minute structure has never, so far
as we are aware, been called in question, we shall occupy some portion
of the space allotted to us in adverting to certain facts of interest,
and shall supplement our observations by some remarks upon the
supposed correspondence, or divergence, in chemical composition
between representative solids and fluids in allied but distinct
species. We must admit, with many other scientific writers, that if
but a very moderate proportion of the arguments advanced by Mr. Darwin
in favour of his conclusions rested upon a really firm basis of fact,
the formation of species by natural selection would be established;
but we have found that in many cases the arguments advanced do not
bear the test of careful analysis, and some assertions crumble into
dust as soon as they are exposed to investigation. We shall find
reason to doubt the validity of Mr. Darwin's inferences concerning
chemical composition, as well as concerning minute structure. Although
undoubtedly, we do discern a general correspondence, the exceptions
are so remarkable, and so far inexplicable upon Mr. Darwin's view,
that we are disposed to think that the argument from it must be
rejected altogether. If we study carefully the minute structure of
corresponding tissues, we shall find that in many instances we are
confronted with the most striking and peculiar differences, which tend
to establish the idea of individuality and distinctness of origin,
rather than that of the community of origin of creatures closely
allied in zoological characters.
The differences in minute details in the case of creatures much alike
are often very remarkable, and well worthy of attentive consideration.
It may be possible to explain some of them by natural selection, but
the way in which this can be done has to be pointed out. Nor is it
easy to see why many individual peculiarities, that could easily be
specified, should exist at all. They are certainly not required by
their possessors, they do not seem either of advantage or
disadvantage, and it is at least conceivable that in minute structure
the tissues of all closely allied animals might exactly resemble one
another. But is it not remarkable that, for instance, almost every
tissue of the newt, frog, toad, and green tree-frog, has individual
characteristics of its own, which could be distinguished by one who
was thoroughly familiar with the microscopic characters of the
textures? In many cases the differences are so wide that they could
not be passed over.[64] In the newt, as would be anticipated, the
elementary parts of the tissues are formed altogether upon a much
larger scale than, in the other animals, and there are individual
differences which are most interesting. The disciples of evolution
might gain some facts in support of their theory by comparing in
minute structure the tissues of the newt and proteus, in which latter
animal everything is on a larger and coarser (?) scale than in the
newt. But would the evolutional hypothesis gain by the application of
such a test?
The nerve-fibres in every part of the body of the newt differ in many
minute particulars from those of the frog, and the muscular fibres of
either animal could be recognised if they were successfully prepared
in precisely the same manner, so that a comparison might be instituted
with fairness. But in these animals not only do corresponding tissues,
exhibit peculiarities, but entire organs are totally different. The
kidney of the frog diverges in so many points of structure from that
of the newt, that the two organs could not be mistaken the one for the
other, even if examined in the most cursory manner. Each individual
tube of the newt's kidney is lined by ciliated epithelium from one end
to the other, while that of the frog is so lined only at the neck. The
Malpighian bodies of the two animals are different, and we believe
that corresponding tissues taken from these organs could be
distinguished from one another. It may be answered, 'This very
instance is in favour of evolution, for the kidney tube gradually
loses its ciliated lining, as we pass from the lower towards the
higher batrachian form. In the latter, only the neck of the tube is
ciliated, while in animals higher in the scale than the batrachia, the
uriniferous tube is perfectly destitute of cilia.' Will the
evolutionist be satisfied with this explanation, or will he suggest
some other?
Again, if we take the skin of the four animals mentioned
above--although it will be seen that there is a certain general
agreement in structure to be recognised, there is not a texture of the
skin which is alike in them all. The cuticle is different, the glands
of the skin are differently arranged, the pigment-cells present the
most marked differences; and individual characteristics are to be
detected in great number by anyone who will study the subject in
detail with sufficient care. We do not, however, suppose for an
instant that Mr. Darwin would be unable upon his hypothesis to offer a
plausible explanation of all these minute points. We are well aware
that this can be done, and in a manner that to some minds may seem
convincing. What we wish to press upon our readers, however, is, that
so far as at this time the argument rests upon a close correspondence
in minute structure, it must be given up, because the asserted close
correspondence in minute structure is not based upon evidence. On the
other hand, actual investigation into the structure of certain
corresponding tissues demonstrates remarkable individual
peculiarities, and these seem to increase in number the more
thoroughly and the more minutely the tissues are explored. What if, in
the case of closely allied species, such structural differences be
demonstrated in every part of the body? Will the fact be urged in
support of a common parentage, or in favour of some different view? It
may be fairly asked, if two closely allied forms have descended from a
common progenitor not far removed from either, why should almost every
tissue and organ in the body exhibit individual peculiarities, not one
of which can be regarded as of advantage to the creature, or as
contributing in any way to its survival? The sensitive fungiform
papillæ of the tongue of the common frog and of the hyla differ from
one another in minute structure, and specimens could be readily
distinguished. Again, it might be asked, why are the hairs of the
shrew different from those of the mole, and why is the disposition of
the nerve-fibres round the hair-bulb even to their minutest fibrils
different in different creatures, all of which possess the particular
hairs called _tactile_, which act as delicate organs of touch? One
would have supposed that the apparatus at the side of the base of a
tactile hair of a shrew would be very like that upon which the tactile
hair of a mole operates, and that the mechanism in both animals would
not differ much from that at the base of the tactile hairs of the
mouse. But the structure of the hair is different in all three, and
the arrangement of the nerves is so different that there would be no
difficulty in distinguishing them from the hair-sac alone. In short,
there are probably very many different forms of tactile organs, in all
of which a hair is the external part, but which organs exhibit
important differences of structure.
If close correspondence in minute structure is to be accepted as an
argument in Mr. Darwin's favour, he will surely hardly venture to
assert that differences in minute structure point to a similar
conclusion, though both sets of facts might be ingeniously used in
support of this eminently elastic hypothesis. If the supposed
correspondence was established, the evolutionist would of course point
to the fact in proof of a common parentage; but if, on the other hand,
the supposed correspondence should be proved to be a fiction, he might
retort triumphantly, 'Only see in what infinitely minute structural
particulars the law of variation by natural selection manifests its
operation!'
How are we to explain the varying form and size of the red
blood-corpuscles in different animals which have been so carefully
examined and measured by Mr. Gulliver? The corpuscles do not vary
according to the size of the animal, nor, unless our views of
classification are utterly erroneous, can any constant relation be
demonstrated between the size and form of the blood-disks of the
creature and its position in the zoological scale. Again, in some
cases, the colourless corpuscles are much larger than the coloured
ones, while in others the very reverse obtains. Moreover, in many
important characters, the blood-corpuscles of animals of the same
class differ remarkably. The writer of this article could multiply
such facts to a great extent from the observations he has been led to
make incidentally, without reference to any hypothesis whatever; but
he feels almost sure that, if a series of observations were made, the
distinctive characters of corresponding textures taken from closely
allied animals would be enormously multiplied. Such minute anatomical
investigation will doubtless be instituted, but at present the leaders
of scientific thought in this country seem to consider that general
observations extending over a wide range of knowledge are preferable.
Mr. Darwin even supposes, or, at any rate, leads his readers to infer
that he supposes, that the investigation of the structural character
of man and animals has been completed, or is nearly completed. It is
evident he would have us believe such to be the case, for he says that
to take any view of man's origin different from his own is to admit
that our own structural characteristic and those of animals are a mere
snare laid to entrap our judgment--as if all our tissues and organs
had been thoroughly and finally explored. We know neither our own
structure nor that of any plant or animal in the world. Mr. Darwin
must surely be aware that the minute anatomy of the body of man or of
animals is not yet in any part fully ascertained. It is possible that,
as Mr. Darwin himself has not worked much at this subject, he may have
been misled by his anatomical friends; but every investigator who goes
into details with due care, and with sufficient accuracy, soon finds
himself compelled not only to correct the facts advanced by those who
have preceded him, but is able to add to known facts many new ones.
There is no reason for thinking that there is any limit to this
discovery of new facts. We may go on discovering for ever, but our
anatomical observations will never be complete; nor must it be
supposed that, even with our present means, our present knowledge of
minute structure is as far advanced as is possible.
Mr. Darwin admits in many instances the existence of certain facts
which he cannot explain by his hypothesis, and in this difficulty he
appeals to our 'belief in the general principle of evolution,' and
suggests that, 'unless we wilfully close our eyes,' we must assent to
a doctrine which he confesses is not proved by the evidence he has
adduced in its support. It is, however, only by wilfully closing our
eyes, and very tightly indeed, and for a long period of time, that we
can hope to force the understanding to accept a belief in the 'general
principles in question.'
The _differences_ observed in the minute structure of corresponding
tissues in closely allied species ought to have more closely engaged
the attention of Mr. Darwin, but he is evidently quite unaware of
either their extent or their number. Had he been alive to these, he
would scarcely have committed himself so fully, or have left so
exposed to attack his argument based on the supposition of close
correspondence in structure. Structural variations in detail are
indeed infinite, and it is extraordinary that Mr. Darwin's assertion
of close correspondence should so long have remained unchallenged.
Whatever may ultimately be accepted as the true explanation of the
fact, it must be admitted that it does not support Mr. Darwin's
hypothesis in its present form.
Structural difference in the tissues and organs of allied species are
not, however, limited to microscopic characters. There are many broad
anatomical distinctions which have never been explained, such as the
absence of a part or organ in an animal very closely related to
numerous other species, in every one of which not only does it exist,
but is largely developed. Such cases may be regarded by the
evolutionist as exceptional, and he may invent some new hypothesis to
account for them. Such facts may be treated as anomalies, and referred
to laws yet to be discovered, upon which correlation of growth
depends. By this old method of overcoming a difficulty, facts which
really tell against the favourite conclusion are made to appear to
tell in its favour; but in science the exception does not prove the
rule. It is clear that very much is thought of the argument from
agreement in general structure between more recent forms and the
ancestral forms from which they are supposed to have descended, for it
has been very pointedly referred to by those who support the
hypothesis of natural selection. If, however, it is proved on more
minute and careful examination that, although there are some points of
resemblance between species, which would render plausible the idea of
a common parentage, there are also striking differences, which
increase in number and importance the more they are sought for, it
will be admitted that the force of this argument is much weakened; and
although, after making allowance for exaggerated expression, we may
admit with Mr. Huxley 'that in every single visible character man
differs less from the higher apes than these do from the lower members
of the same order of primates,' we are nevertheless compelled by the
facts to maintain that there are so very many points in which man
differs from every ape, that the argument in favour of close
relationship based upon correspondence in structure completely breaks
down. In fact, the differences that cannot be accounted for upon the
hypothesis are more important and more numerous than the resemblances
which it is advanced to explain. Of what worth is an argument resting
on the fact of hundreds of representative muscles, tendons, bones, and
eminences on bones, in closely allied species, if the very muscles,
tendons, and bones themselves exhibit minute and constant structural
differences? And if, besides these anatomical differences, we meet
with differences as regards the rate of development--differences in
the order of development of certain tissues and organs--differences in
the structural changes going on after development is complete, what
shall we infer?
It is all very well to explain the presence of muscular variations in
man by the tendency to reversion to an earlier condition of existence,
but it is of the utmost importance in the first place to be sure that
our evidence justifies us in concluding that particular and
exceptional muscles in man representing muscles highly developed in
some of the lower animals owe their origin to descent. This is the
very question upon which proof is wanting. The variations _may_ be due
to descent, but it by no means follows that they _must_ be due to
descent, and it is still more difficult to be certain that they are
not due to the operation of some _undiscovered factor_.
For many years past, naturalists, in their desire to discover the
relationship between the many divergent forms of living things, appear
to have closed their eyes to the remarkable differences which
establish distinct characteristics between very closely allied forms,
and which tend to show that the latter are not so closely related as
the hypothesis of Darwin concludes. What, for instance, is the
explanation of the fact that in no two animals or men are the branches
of the arteries or nerves given off from the larger trunks at
precisely the same points or in precisely the same manner, and why are
variations in the muscles to be detected in each individual
subject?--we cannot call them _accidental_. Will descent account for
the hundreds of variations we meet with, as well as for those
particular kinds which have been minutely described by Mr. Wood and
others, and of which the evolutionists have made so much? Here, as in
many other instances, we find inferences based on a very one-sided, if
not a very imperfect statement of the facts. In order to account for
all the anatomical varieties, it will be necessary again to call in
the help of that 'unknown law' which the advocates of natural
selection invoke when they find themselves in a difficulty.
But we come now to consider whether Mr. Darwin is more correct in his
assertion concerning the close correspondence in the chemical
composition of the tissues and fluids of the different species, than
he is upon the question of minute structure. How is it that we find
specific characters in the blood, bile, milk, saliva, gastric juice,
urine, and other fluids and secretions of nearly related animals? The
blood of the Guinea pig differs in important characteristics from that
of the rat, mouse, rabbit, and squirrel. The most important
constituent of the blood undergoes crystallization, and the form of
the blood crystal is very different in the several members of the
rodent class. By some undiscovered law of correlation of growth,
perhaps, may be explained the curious fact that the blood-corpuscles
of the tailless Guinea pig crystallize very readily in beautiful
tetrahedra, while those of another rodent in which the tail is
remarkably developed take the form of six-sided plates, and in yet
another which possesses only a faint apology for a caudal appendage,
we find blood crystals taking the form of the most beautiful
rhomboids.
The blood of one species will not efficiently nourish the tissues of
another; and in cases in which life is temporarily supported by alien
blood artificially introduced into the vessels, it is probable that
the foreign fluid is gradually destroyed and eliminated, and at last,
entirely replaced by blood which is slowly formed anew in the animal's
own vessels. Not only does the blood of man differ from that of the
lower animals, but the blood of every species of animal differs from
that of every other species.
But if we submit any of the other fluids mentioned above to careful
chemical and physical analysis, we shall find each endowed with
special characteristic properties, and distinguished from the rest by
well-marked and constant characters; and we have reason to believe
that the more minutely such investigation is carried out, the larger
will be the number of divergent characters and properties established.
Mr. Sorby has lately been examining, by the aid of the spectroscope,
many of the colouring matters of the leaves and petals of flowers and
plants, and has demonstrated the presence of a large number of new
substances which can be most positively distinguished from one another
by spectrum analysis. Substances belonging to different plants which
appear to the eye of nearly the same tint, often exhibit very
different characters when submitted to spectroscopic examination.[65]
There seems to be, in fact, no limit to divergence in essential
particulars in cases in which the correspondence is only to be found
in most general and superficial characters. We will recur for a moment
to the question of minute structure as illustrated by plants. If the
reader will be at the trouble of placing under his microscope, one
after another, the petals of any half-dozen flowers of a red or blue
colour, he will soon be able to discover anatomical differences by
which each of them could be recognised independently of its colour.
Moreover, if he studies the subject with sufficient care, he will find
that new structural peculiarities will be demonstrated, of the
existence of which he had no idea when the investigation was
commenced.
Series of facts like those adduced above not only seem to militate
against the acceptance of the doctrine of natural selection in its
present form, but they cannot be contemplated without exciting in the
mind a desire to entertain the hypothesis of fixity of species, or
some derivative hypothesis not opposed to that idea.
Although of late much attention has been given to variation, the
inheritance of variability, and progressive hereditary changes in the
structure of the body, the advocates of evolution have only advanced
statements of the most general kind. They have not entered into
details; they have not suggested at what particular period in the life
of the individual the change in structure occurs. They are silent as
to the precise nature of the change, and the several steps by which it
is brought about; and they say nothing concerning the characters and
properties of the matter, which is the actual seat of the change. It
is not sufficient to show us the bone or muscle, the structure of
which is modified, and to assure us that the modification in question
is due to the law of variability; for the hypothesis deals with the
change itself, and we should be informed concerning the phenomenon
which are antecedent to the change, and the exact circumstances which
determine any particular modification advanced in illustration of the
working of the supposed law. Further, it should be definitely
determined what degree of change suffices to affect the fully-formed
bone and muscle, and whether structural changes occurring at or after
the period of full development of the body are inherited or not. The
reader is probably aware that Mr. Darwin has invented an hypothesis
specially to meet this part of the question--the hypothesis of
Pangenesis. But he has recently remarked that it has not yet received
its 'death-blow'--an observation which excites a doubt whether its
author is not ready to abandon it. This hypothesis was only advanced
tentatively from the first. It is incompatible with a number of facts,
and appears more and more improbable as the phenomena it comprises are
carefully investigated. Many observers well qualified to form a
correct judgment felt almost certain from the very first that
Pangenesis could not be maintained.
Seeing that, at every period of life, matter exists in every part of
the body in at least two very different states, in each of which
different classes of phenomena occur, Mr. Darwin should have informed
us in what particular matter of the body in his opinion the metabolic
property probably resided, and he should have explained at what period
of life the change which was to result in the production of a new
variety or species occurred. He does not, of course, suppose that
fully-formed bone, or muscle, or nerve, changes its characters; nor
would he maintain that in old age, or indeed long after adult life had
been attained, any great alteration of structural form was possible.
If, then, it is only in the plastic state during the early period of
development that the changes surmised to take place can occur, the
author of the hypothesis should either have given more information
upon the details, or he should at the least have shown that
microscopical observation had yielded no facts adverse to his
doctrine; and something surely should have been suggested concerning
the nature and origin of the inherent metabolic property, or tendency,
or capacity, which is assumed by the terms of the hypothesis.
It should, however, be stated here that many evolutionists repudiate
entirely the idea of any peculiar property under any circumstances
influencing matter in the living state which does not influence it in
the non-living condition, for the acceptance of the idea of such
property would involve an answer to the inquiry as to the nature and
origin of the property assumed, and it would have to be shown when and
under what circumstances it was acquired by the matter. The
evolutionist believes only in the properties which belong to matter as
matter, and which are coexistent with the matter itself. The admission
of an inherent property peculiar to the living state of matter, almost
amounts to the admission of a vital power; but such an hypothesis, it
need scarcely be said, would be incompatible with the doctrine of
evolution. But physical evolutionists who persist in attributing all
the phenomena of living beings to physical agencies only, ignore the
most important changes occurring in every form of living matter. Again
and again, they repeat the statement that the changes in living matter
are molecular; but this is merely a word which is perfectly
meaningless as applied to the changes in question, since the
'molecule' is undefined, has not been described, and is quite unknown.
The very same authorities acknowledge that conclusions not based upon
evidence cannot advance science, or be looked upon as scientific, and
yet, with an inconsistency that is extraordinary, they state with
confidence that they understand the nature of these changes. But they
have not been able to learn anything of them whatever by experiment,
nor can they discover any means of imitating them in matter in the
laboratory. The changes in question are quite peculiar to living
matter; they occur in all living matter, but in living matter only.
These changes differ entirely from any other changes of which we have
any cognizance. Nothing surely can be more illogical or unscientific
than to assert that actions about which we know nothing are of the
same kind or nature as actions which are understood, and can be
brought about whenever we will. Yet physicists, chemists, and indeed
most scientific men, have fully committed themselves to the dogmatic
creed that the phenomena of living matter are, like all the other
phenomena of nature, due to antecedent physical change. There are no
physical phenomena to which they can point, that in the remotest
degree resemble the actions peculiar to living matter.
Variation itself is quite peculiar, and as far removed from any
physical change as is possible to conceive. The extent of variation,
and of variations inherited from ancestors, is perfectly marvellous.
Such variations are carried out during that plastic period of life
when the body consists almost entirely of living matter, and occur in
every individual of every species of animal and plant that is known.
Each is _like_ its predecessors, but not one is in any part _exactly
like_ the corresponding part of any predecessor. No two individuals
were ever formed exactly alike in all particulars. Nay, it is doubtful
if any two vital actions that have taken place in nature have been
perfectly alike in all points.
That variation occurs in the plastic matter of the organism, while the
formative process is taking place, is a truism, for no two noses or
fingers, or other parts, have been seen so much alike as not to be
distinguishable from one another; nay, it is not supposable that any
two should be found precisely similar. Perfect identity in structures
of such complexity is indeed hardly conceivable, unless many facts
known in connection with tissue formation are utterly ignored. But, on
the other hand, it is equally inconceivable that capacity for
variability should be manifested in such a manner and to such an
extent as to lead to the production of a proboscis in place of a nose,
or of a talon in lieu of a finger. Hence, therefore, we must admit
that this capacity works within certain, though at this time not to be
accurately defined, limits. When, therefore, Mr. Darwin maintains that
similarity of pattern between the flipper of the seal, the wing of the
bat, the hand of the man, &c., is due to divergence in structure
during gradual descent from a common progenitor, does he not beg the
question at issue, and by implication assume an extent of variation
far exceeding that which is possible within the period of time which
he is disposed to think may have elapsed during which the hundreds or
thousands of transitional forms have been slowly progressing towards
perfection of type? Undoubtedly, if he could show one or two
gradations between the paw of the bear and the flipper of the seal, or
between the foot of the mole and the wing of the bat, he would have a
powerful argument indeed. But the mind fails to realize the
possibility of the transitional forms whose existence is assumed by
the hypothesis. A thing half bear and half seal, or half mole and half
bat, would be an incongruity which we have no right to assume ever
existed in the flesh, if indeed it is not absurd to suppose it
possible. If such a creature were born, it would die, and the very law
of natural selection supposed to operate in favour of its development
would render certain its destruction without offspring.
Variation in the living world seems to be indeed infinite, but
nevertheless, so to say, restrained within limits. When we come to
study variation in any particular species, we marvel at the
extraordinary extent of change to be observed without any approach
being recognized towards the nearest allied species. The human face
may vary, we may say, infinitely, but without in the slightest degree
approximating the face of a monkey or any other animal. The animal
face and features may vary infinitely within the animal limits without
manifesting the slightest approach to the human countenance, or even
to that of any other species of animal. Any species of monkey might
become modified in many different directions without making any
approach to the human form. The ass might change for ages, and yet be
something very different from a horse, and so on in other cases. The
most degraded savage exhibits no approach to the ape, any more than
the most highly developed species of monkey exhibits any nearer
approach to man than the very lowest member of its class. There are
human variations, monkey variations, ass variations, &c., without end,
but there is no evidence of any variations occurring in one species
which tend to show that it possesses any intimate relationship with
any different species. The facts hitherto discovered, and considered
by Mr. Darwin to support the view that we have descended or ascended
from monkeys appear to us, therefore, to be very inconclusive and
unsatisfactory. We are quite ready to consider patiently every
argument that evolutionists can adduce, and if we think the case
proved, we are fully prepared to admit it, but when told that we
_must_ accept the doctrine, we distrust our would-be teachers. In the
suggestion of the alternative, 'accept this hypothesis or none,'
there is the suspicion of a threat which ought to be received with
indignation. The world may be wanting in scientific knowledge and
acumen, but it will never submit to dictatorial science. The world is
quite ready to be taught, and to learn, but it will not endure a
tyranny enforced by persons who choose to call themselves,
philosophers, and who claim to be scientifically infallible. The world
knows something of the history of scientific controversies, and will
listen with caution, but it rejects upon principle the application of
scientific tests, and refuses point blank to subscribe to any articles
of scientific belief, or to acknowledge an infallible scientific head.
After all that can be said against evolution has been uttered, there
remains the defence that the hypothesis _rests upon a vast array of
facts_--anatomical, physiological, geological--and 'it is scarcely
fair,' it may be urged, 'to expect that a generalization which
explains so much, should fully account for every slight divergence of
structure that can be rendered evident by exquisitely minute and
careful investigation.' But surely a view of such wide general
application as this is held to be by its supporters ought not to fail
when tested by particular facts of general observation. Unfortunately,
Mr. Darwin's hypothesis is not adequately supported by the very facts
upon which he relies for proof; for out of the multitudes of living
beings now existing upon the earth, he cannot select any two species
whose differences and resemblances can be fully accounted for by the
hypothesis which he holds to be universally applicable, and to account
for the origin of every species from the monad to man. What must be
the ultimate verdict passed upon a doctrine aspiring to universal
application, which seems satisfactory only when vaguely applied, and
which utterly fails when tested by the individual particulars that are
comprised in the generalities? We may be like the savage, as Mr.
Darwin suggests, but we are by no means convinced by the arguments
adduced by him that man is the co-descendant, with other mammals, of a
common progenitor, nor can we admit that certain structural
peculiarities of man's bodily frame are to be looked upon as 'the
indelible stamp of his lowly origin.'
All naturalists will agree in believing that there is some truth in
the doctrine which Mr. Darwin has so thoroughly espoused, but there
will be the greatest difference of opinion concerning the acceptance
of many of his propositions; while it must be confessed that the more
minutely and carefully we analyze the data upon which some of his
conclusions rest, the less satisfied are we that they should be relied
upon. Indeed, there is reason to think that at least one of his
subordinate hypotheses, Pangenesis, will certainly have to be
abandoned as untenable. As we have before remarked in this article,
neither Mr. Darwin nor those who think with him appear to realize the
illimitable possible additions to scientific knowledge, and
consequently the continued change in scientific opinion, the
abandonment of old hypotheses, and the development of new ones. Never
in the history of science have such startling hypotheses been
successively advanced as during the last twenty years. Few have stood
the test of one quinquennial period, and not one has been retained in
its original form. The sentiment, as expressed by Mr. Darwin, 'We are
not concerned with hopes or fears, only with the truth,' is a
favourite one with scientific men, but the truth has not yet been
arrived at. Is scientific truth ever to be reached? The nearer we seem
to get to actual scientific truth, the more quickly does it recede
from us; and it has happened but too often that when we thought to
have grasped it, we find it far away, and that what in youth we
thought to be scientific truth, afterwards, but long before we have
reached old age, is proved to be scientific error.
In conclusion, therefore, we must remark, that while the hypothesis
fails in individual cases to which it has been applied, it is
incompetent to explain numerous facts known in connection with every
particular plant or animal in existence. But, further, the general
facts ascertained by careful and more minute investigation into the
anatomy and physiology of any two closely allied species, such, for
example, as the hare and the rabbit, the rat and the squirrel, the
Guinea pig, or the hyla and common frog, are inexplicable upon the
doctrine of natural selection, even if the time were extended far
beyond the limits which upon other grounds it is not permissible to
suppose it to stretch. Nay, the series of changes believed to occur
during the formation of species by natural selection cannot be
conceived by the imagination, unless multitudes of facts which have
been demonstrated and can be confirmed by anyone who will take the
trouble to do so are completely ignored. That man is like an ape, bone
for bone, muscle for muscle, &c., is only a flourish of rhetoric
unworthy of anyone who professes himself to be an observer of nature.
The remarks which have been made in respect to animals apply with
marvellously greater force to man himself, for no matter how the
evolutionists may strain the force of the analogies existing between
man and animals, there are transcendent differences which no sophistry
can explain away. We may allow Mr. Darwin and his friends to draw on
time as largely as they may desire, we will permit them to strain to
any extent they like the argument that the ape differs in far greater
degree from the lower animals than he does from man himself, and we
could yet succeed in exposing the improbability of the favoured
hypothesis by discussing with its advocates its insufficiency to
account for one single characteristic, such, for example, as the
possession by man of the power of expressing his ideas. It is surely
not likely that the attempt to found a general argument on the nature,
mode of origin, and formation of all living beings, upon the points in
which they exhibit some resemblance to one another, without showing in
what manner the argument in question would be affected by the
characters in which these same beings differ from one another, will
much longer be regarded as a triumph of inductive reasoning, or
considered to be in accordance with the spirit of science or true
philosophy.