"It seems to me that there is much confusion of ideas in the general
statement of the variability of species so often repeated lately. If
species do not exist at all, as the supporters of the transmutation
theory maintain, how can they vary? and if individuals alone exist,
how can the differences which may be observed among them prove the
variability of species?"
Now we imagine that Mr. Darwin need not be dangerously gored by either
horn of this curious dilemma. Although we ourselves cherish
old-fashioned prejudices in favor of the probable permanence, and
therefore of a more stable objective ground of species, yet we
agree--and Mr. Darwin will agree fully with Mr. Agassiz--that species,
and he will add varieties, "exist as categories of thought," that is,
as cognizable distinctions,--which is all that we can make of the
phrase here, whatever it may mean in the Aristotelian metaphysics.
Admitting that species are only categories of thought, and not facts
or things, how does this prevent the individuals, which are material
things, from having varied in the course of time, so as to exemplify
the present almost innumerable categories of thought, or embodiments
of Divine thoughts in material forms, or--viewed on the human side--in
forms marked with such orderly and graduated resemblances and
differences as to suggest to our minds the idea of species, genera,
orders, etc., and to our reason the inference of a Divine original? We
have no clear idea how Mr. Agassiz intends to answer this question, in
saying that branches are founded upon different plans of structure,
classes upon different modes of execution of these plans, orders on
different degrees of complication in the mode of execution, families
upon different patterns of form, genera upon ultimate peculiarities of
structure, and species upon relations and proportions. That is, we do
not perceive how these several "categories of thought" exclude the
possibility or the probability that the individuals which manifest or
suggest the thoughts had an ultimate community of origin. Moreover,
Mr. Darwin would insinuate that the particular philosophy of
classification upon which this whole argument reposes is as purely
hypothetical and as little accepted as his own doctrine. If both are
pure hypotheses, it is hardly fair or satisfactory to extinguish the
one by the other. If there is no real contradiction between them,
there is no use in making the attempt.
As to the dilemma propounded, suppose we try it upon that category of
thought which we call _chair_. This is a genus, comprising the common
chair, (_Sella vulgaris_,) the arm or easy chair, (_S. cathedra_,) the
rocking chair, (_S. oscillans_,) widely distributed in the United
States, and some others,--each of which has _sported_, as the
gardeners say, into many varieties. But now, as the genus and the
_species_ have no material existence, how can they vary? If
individuals alone exist, how can the differences which may be observed
among them prove the variability of the species? To which we reply by
asking, Which does the question refer to, the category of thought, or
the individual embodiment? If the former, then we would remark that
our categories of thought vary from time to time in the readiest
manner. And, although the Divine thoughts are eternal, yet they are
manifested in time and succession, and by their manifestation only can
we know them, how imperfectly! Allowing that what has no material
existence can have had no material connection and no material
variation, we should yet infer that what had intellectual existence
and connection might have intellectual variation; and, turning to the
individuals which represent the species, we do not see how all this
shows that they may not vary. Observation shows us that they do.
Wherefore, taught by fact that successive individuals do vary, we
safely infer that the idea or intention must have varied, and that
this variation of the individual representatives proves the
variability of the species, whether subjectively or objectively
regarded.
Each species or sort of chair, as we have said, has its varieties, and
one species shades off by gradations into another. And--note it
well--these numerous and successively slight variations and
gradations, far from suggesting an accidental origin to chairs and to
their forms, are very proofs of design.
Again, _edifice_ is a generic category of thought. Egyptian, Grecian,
Byzantine, and Gothic buildings are well-marked species, of which each
individual building of the sort is a material embodiment. Now the
question is, whether these categories of thought may not have been
evolved, one from another, in succession, or from some primal, less
specialized, edificial category. What better evidence for such
hypothesis could we have than the variations and grades which connect
one of these species with another? We might extend the parallel, and
get some good illustrations of natural selection from the history of
architecture, the probable origin of the different styles, and their
adaptation to different climates and conditions. Two qualifying
considerations are noticeable. One, that houses do not propagate, so
as to produce continuing lines of each sort and variety; but this is
of small moment on Agassiz's view, he holding that genealogical
connection is not of the essence of species at all. The other, that
the formation and development of the ideas upon which human works
proceed is gradual; or, as the same great naturalist well states it,
"while human thought is consecutive, Divine thought is simultaneous."
But we have no right to affirm this of Divine action.
We must close here. We meant to review some of the more general
scientific objections which we thought not altogether tenable. But,
after all, we are not so anxious just now to know whether the new
theory is well founded on facts as whether it would be harmless, if it
were. Besides, we feel quite unable to answer some of these
objections, and it is pleasanter to take up those which one thinks he
can.
Among the unanswerable, perhaps the weightiest of the objections, is
that of the absence, in geological deposits, of vestiges of the
intermediate forms which the theory requires to have existed. Here all
that Mr. Darwin can do is to insist upon the extreme imperfection of
the geological record and the uncertainty of negative evidence. But,
withal, he allows the force of the objection almost as much as his
opponents urge it,--so much so, indeed, that two of his English
critics turn the concession unfairly upon him, and charge him with
actually basing his hypothesis upon these and similar
difficulties,--as if he held it because of the difficulties, and not
in spite of them;--a handsome return for his candor!
As to this imperfection of the geological record, perhaps we should
get a fair and intelligible illustration of it by imagining the
existing animals and plants of New England, with all their remains and
products since the arrival of the Mayflower, to be annihilated; and
that, in the coming time, the geologists of a new colony, dropped by
the New Zealand fleet on its way to explore the ruins of London,
undertake, after fifty years of examination, to reconstruct in a
catalogue the flora and fauna of our day, that is, from the close of
the glacial period to the present time. With all the advantages of a
surface exploration, what a beggarly account it must be! How many of
the land animals and plants which are enumerated in the Massachusetts
official reports would it be likely to contain?
Another unanswerable question asked by the Boston reviewers is, Why,
when structure and instinct or habit vary,--as they must have varied,
on Darwin's hypothesis,--they vary together and harmoniously, instead
of vaguely. We cannot tell, because we cannot tell why either should
vary at all. Yet, as they both do vary in successive generations,--as
is seen under domestication,--and are correlated, we can only adduce
the fact. Darwin may be precluded from this answer, but we may say
that they vary together because designed to do so. A reviewer says
that the chance of their varying together is inconceivably small; yet,
if they do not, the variant individuals must perish. Then it is well
that it is not left to chance. As to the fact: before we were born,
nourishment and the equivalent to respiration took place in a certain
way. But the moment we were ushered into this breathing world, our
actions promptly conformed, both as to respiration and nourishment, to
the before unused structure and to the new surroundings.
"Now," says the "Examiner," "suppose, for instance, the gills of an
aquatic animal converted into lungs, while instinct still compelled a
continuance under water, would not drowning ensue?" No doubt.
But--simply contemplating the facts, instead of theorizing--we notice
that young frogs do not keep their heads under water after ceasing to
be tadpoles. The instinct promptly changes with the structure, without
supernatural interposition,--just as Darwin would have it, if the
development of a variety or incipient species, though rare, were as
natural as a metamorphosis.
"Or if a quadruped, not yet furnished with wings, were suddenly
inspired with the instinct of a bird, and precipitated itself from a
cliff, would not the descent be hazardously rapid?" Doubtless the
animal would be no better supported than the objection. Darwin makes
very little indeed of voluntary efforts as a cause of change, and even
poor Lamarck need not be caricatured. He never supposed that an
elephant would take such a notion into his wise head, or that a
squirrel would begin with other than short and easy leaps; but might
not the length of the leap be increased by practice?
The "North American" reviewer's position, that the higher brute
animals have comparatively little instinct and no intelligence, is a
heavy blow and great discouragement to dogs, horses, elephants, and
monkeys. Stripped of their all, and left to shift for themselves as
they can in this hard world, their pursuit and seeming attainment of
knowledge under such peculiar difficulties is interesting to
contemplate. However, we are not so sure as is the critic that
instinct regularly increases downward and decreases upward in the
scale of being. Now that the case of the bee is reduced to moderate
proportions,[12] we know of nothing in instinct surpassing that of an
animal so high as a bird, the Talegal, the male of which plumes
himself upon making a hot-bed in which to hatch his partner's
eggs,--which he tends and regulates the heat of about as carefully and
skilfully as the unplumed biped does an eccaleobion.[13] As to the
real intelligence of the higher brutes, it has been ably defended by a
far more competent observer, Mr. Agassiz, to whose conclusions we
yield a general assent, although we cannot quite place the best of
dogs "in that respect upon a level with a considerable portion of poor
humanity," nor indulge the hope, or, indeed, the desire, of a renewed
acquaintance with the whole animal kingdom in a future life.[14]
The assertion, that acquired habitudes or instincts, and acquired
structures, are not heritable, any breeder or good observer can
refute.
That "the human mind has become what it is out of a developed
instinct"[15] is a statement which Mr. Darwin nowhere makes, and, we
presume, would not accept. As to his having us believe that individual
animals acquire their instincts gradually,[16] this statement must
have been penned in inadvertence both of the very definition of
instinct, and of everything we know of in Mr. Darwin's book.
It has been attempted to destroy the very foundation of Darwin's
hypothesis by denying that there are any wild varieties, to speak of,
for natural selection to operate upon. We cannot gravely sit down to
prove that wild varieties abound. We should think it just as necessary
to prove that snow falls in winter. That variation among plants cannot
be largely due to hybridism, and that their variation in Nature is not
essentially different from much that occurs in domestication, we could
show, if our space permitted.
As to the sterility of hybrids, that can no longer be insisted upon as
absolutely true, nor be practically used as a test between species and
varieties, unless we allow that hares and rabbits are of one species.
That it subserves a purpose in keeping species apart, and was so
designed, we do not doubt. But the critics fail to perceive that this
sterility proves nothing against the derivative origin of the actual
species; for it may as well have been intended to keep separate those
forms which have reached a certain amount of divergence as those which
were always thus distinct.
The argument for the permanence of species, drawn from the identity
with those now living of cats, birds, and other animals, preserved in
Egyptian catacombs, was good enough as used by Cuvier against St.
Hilaire, that is, against the supposition that time brings about a
gradual alteration of whole species; but it goes for little against
Darwin, unless it be proved that species never vary, or that the
perpetuation of a variety necessitates the extinction of the parent
breed. For Darwin clearly maintains--what the facts warrant--that the
mass of a species remains fixed so long as it exists at all, though it
may set off a variety now and then. The variety may finally supersede
the parent form, but it may coexist with it; yet it does not in the
least hinder the unvaried stock from continuing true to the breed,
unless it crosses with it. The common law of inheritance may be
expected to keep both the original and the variety mainly true as long
as they last, and none the less so because they have given rise to
occasional varieties. The tailless Manx cats, like the fox in the
fable, have not induced the normal breeds to dispense with their
tails, nor have the Dorkings (apparently known to Pliny) affected the
permanence of the common sort of fowl.
As to the objection, that the lower forms of life ought, on Darwin's
theory, to have been long ago improved out of existence, replaced by
higher forms, the objectors forget what a vacuum that would leave
below, and what a vast field there is to which a simple organization
is best adapted, and where an advance would be no improvement, but the
contrary. To accumulate the greatest amount of being upon a given
space, and to provide as much enjoyment of life as can be under the
conditions, seems to be aimed at, and this is effected by
diversification.
Finally, we advise nobody to accept Darwin's, or any other derivative
theory, as true. The time has not come for that, and perhaps never
will. We also advise against a similar credulity on the other side, in
a blind faith that species--that the manifold sorts and forms of
existing animals and vegetables--"have no secondary cause." The
contrary is already not unlikely, and we suppose will hereafter become
more and more probable. But we are confident, that, if a derivative
hypothesis ever is established, it will be so on a solid theistic
ground.
Meanwhile an inevitable and legitimate hypothesis is on trial,--an
hypothesis thus far not untenable,--a trial just now very useful to
science, and, we conclude, not harmful to religion, unless injudicious
assailants temporarily make it so.
One good effect is already manifest: its enabling the advocates of the
hypothesis of a multiplicity of human species to perceive the double
insecurity of their ground. When the races of men are admitted to be
of one species, the corollary, that they are of one origin, may be
expected to follow. Those who allow them to be of one species must
admit an actual diversification into strongly marked and persistent
varieties, and so admit the basis of fact upon which the Darwinian
hypothesis is built; while those, on the other hand, who recognize a
diversity of human species, will hardly be able to maintain that such
species were primordial and supernatural in the common sense of the
word.
The English mind is prone to positivism and kindred forms of
materialistic philosophy, and we must expect the derivative theory to
be taken up in that interest. We have no predilection for that school,
but the contrary. If we had, we might have looked complacently upon a
line of criticism which would indirectly, but effectively, play into
the hands of positivists and materialistic atheists generally. The
wiser and stronger ground to take is, that the derivative hypothesis
leaves the argument for design, and therefore for a Designer, as valid
as it ever was;--that to do any work by an instrument must require,
and therefore presuppose, the exertion rather of more than of less
power than to do it directly;--that whoever would be a consistent
theist should believe that Design in the natural world is coextensive
with Providence, and hold fully to the one as he does to the other, in
spite of the wholly similar and apparently insuperable difficulties
which the mind encounters whenever it endeavors to develop the idea
into a complete system, either in the material and organic, or in the
moral world. It is enough, in the way of obviating objections, to show
that the philosophical difficulties of the one are the same, and only
the same, as of the other.
[Footnote 1: Whatever it may be, it is not "the homoeopathic form of
the transmutative hypothesis," as Darwin's is said to be, (p. 252,
Amer. reprint,) so happily that the prescription is repeated in the
second (p. 259) and third (p. 271) dilutions, no doubt, on Hahnemann's
famous principle, with an increase of potency at each dilution.
Probably the supposed transmutation is _per saltus_. "Homoeopathic
doses of transmutation," indeed! Well, if we really must swallow
transmutation in some form or other, as this reviewer intimates, we
might prefer the mild homoeopathic doses of Darwin's formula to the
allopathic bolus which the Edinburgh general practitioner appears to
be compounding.]
[Footnote 2: Vide _North American Review_, for April, 1860, p. 475,
and _Christian Examiner_, for May, p. 457.]
[Footnote 3: Page 188, English ed.]
[Footnote 4: In _American Journal of Science_, July, 1860, pp. 148,
149.]
[Footnote 5: In _Contributions to the Nat. Hist. of U. S._, Vol. i.
pp. 128, 129.]
[Footnote 6: _Contr. Nat. Hist. U.S._, Vol. i. p. 130; and _Amer.
Journal of Science_, July, 1860, p. 143.]
[Footnote 7: _North American Review_, for April, 1860, p. 506.]
[Footnote 8: _Vide_ mottoes to the second edition of Darwin's work.]
[Footnote 9: _North American Review_, l.c. p. 504.]
[Footnote 10: _North American Review_, l.c. p. 487, _et passim._]
[Footnote 11: _In American Journal of Science_, July, 1860, p. 143.]
[Footnote 12: _Vide_ article by Mr. C. Wright, in the _Mathematical
Monthly_ for May last.]
[Footnote 13: Vide _Edinburgh Review_ for January, 1860, article on
"Acclimatization," etc.]
[Footnote 14: _Contributions; Essay on Classification_, etc., Vol. i.
pp. 60-66.]
[Footnote 15: _North Amer. Review_, April, 1860, p. 475.]
[Footnote 16: _Amer. Journal of Science_, July, 1860, p. 146.]
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