ted by selection; secondly, he attempts to show that natural
causes are competent to exert selection; and thirdly, he tries to prove
that the most remarkable and apparently anomalous phaenomena exhibited by
the distribution, development, and mutual relations of species, can be
shown to be deducible from the general doctrine of their origin, which
he propounds, combined with the known facts of geological change; and
that, even if all these phaenomena are not at present explicable by it,
none are necessarily inconsistent with it.

There cannot be a doubt that the method of inquiry which Mr. Darwin has
adopted is not only rigorously in accordance with the canons of
scientific logic, but that it is the only adequate method. Critics
exclusively trained in classics or in mathematics, who have never
determined a scientific fact in their lives by induction from experiment
or observation, prate learnedly about Mr. Darwin's method, which is not
inductive enough, not Baconian enough, forsooth, for them. But even if
practical acquaintance with the process of scientific investigation is
denied them, they may learn, by the perusal of Mr. Mill's admirable
chapter "On the Deductive Method," that there are multitudes of
scientific inquiries, in which the method of pure induction helps the
investigator but a very little way.

"The mode of investigation," says Mr. Mill, "which, from the proved
inapplicability of direct methods of observation and experiment,
remains to us as the main source of the knowledge we possess, or
can acquire, respecting the conditions and laws of recurrence of
the more complex phaenomena, is called, in its most general
expression, the deductive method, and consists of three operations:
the first, one of direct induction; the second, of ratiocination;
and the third, of verification."

Now, the conditions which have determined the existence of species are
not only exceedingly complex, but, so far as the great majority of them
are concerned, are necessarily beyond our cognizance. But what Mr.
Darwin has attempted to do is in exact accordance with the rule laid
down by Mr. Mill; he has endeavoured to determine certain great facts
inductively, by observation and experiment; he has then reasoned from
the data thus furnished; and lastly, he has tested the validity of his
ratiocination by comparing his deductions with the observed facts of
Nature. Inductively, Mr. Darwin endeavour