Darwiniana | Page 5

origin.
The theory of Agassiz regards the origin of species and their present
general distribution over the world as equally primordial, equally
supernatural; that of Darwin, as equally derivative, equally natural.
The theory of Agassiz, referring as it does the phenomena both of
origin and distribution directly to the Divine will--thus removing the
latter with the former out of the domain of inductive science (in which
efficient cause is not the first, but the last word)--may be said to be
theistic to excess. The contrasted theory is not open to this objection.
Studying the facts and phenomena in reference to proximate causes,
and endeavoring to trace back the series of cause and effect as far as
possible, Darwin's aim and processes are strictly scientific, and his
endeavor, whether successful or futile, must be regarded as a legitimate
attempt to extend the domain of natural or physical science. For,
though it well may be that "organic forms have no physical or
secondary cause," yet this can be proved only indirectly, by the failure
of every attempt to refer the phenomena in question to causal laws. But,
however originated, and whatever be thought of Mr. Darwin's arduous
undertaking in this respect, it is certain that plants and animals are
subject from their birth to physical influences, to which they have to
accommodate themselves as they can. How literally they are "born to
trouble," and how incessant and severe the struggle for life generally is,
the present volume graphically describes. Few will deny that such
influences must have gravely affected the range and the association of
individuals and species on the earth's surface. Mr. Darwin thinks that,
acting upon an inherent predisposition to vary, they have sufficed even
to modify the species themselves and produce the present diversity. Mr.
Agassiz believes that they have not even affected the geographical
range and the actual association of species, still less their forms; but
that every adaptation of species to climate, and of species to species, is
as aboriginal, and therefore as inexplicable, as are the organic forms
themselves.
Who shall decide between such extreme views so ably maintained on
either hand, and say how much of truth there may be in each? The
present reviewer has not the presumption to undertake such a task.
Having no prepossession in favor of naturalistic theories, but struck
with the eminent ability of Mr. Darwin's work, and charmed with its

fairness, our humbler duty will be performed if, laying aside prejudice
as much as we can, we shall succeed in giving a fair account of its
method and argument, offering by the way a few suggestions, such as
might occur to any naturalist of an inquiring mind. An editorial
character for this article must in justice be disclaimed. The plural
pronoun is employed not to give editorial weight, but to avoid even the
appearance of egotism, and also the circumlocution which attends a
rigorous adherence to the impersonal style.
We have contrasted these two extremely divergent theories, in their
broad statements. It must not be inferred that they have no points nor
ultimate results in common.
In the first place, they practically agree in upsetting, each in its own
way, the generally-received definition of species, and in sweeping away
the ground of their objective existence in Nature. The orthodox
conception of species is that of lineal descent: all the descendants of a
common parent, and no other, constitute a species; they have a certain
identity because of their descent, by which they are supposed to be
recognizable. So naturalists had a distinct idea of what they meant by
the term species, and a practical rule, which was hardly the less useful
because difficult to apply in many cases, and because its application
was indirect: that is, the community of origin had to be inferred from
the likeness; such degree of similarity, and such only, being held to be
con-specific as could be shown or reasonably inferred to be compatible
with a common origin. And the usual concurrence of the whole body of
naturalists (having the same data before them) as to what forms are
species attests the value of the rule, and also indicates some real
foundation for it in Nature. But if species were created in numberless
individuals over broad spaces of territory, these individuals are
connected only in idea, and species differ from varieties on the one
hand, and from genera, tribes, etc., on the other, only in degree; and no
obvious natural reason remains for fixing upon this or that degree as
specific, at least no natural standard, by which the opinions of different
naturalists may be correlated. Species upon this view are enduring, but
subjective and ideal. Any three or more of the human races, for
example, are species or not species, according to the bent