"a continuous creative operation," "a constantly operating secondary
creational law," through which species are successively produced; and
he emits faint, but not indistinct, glimmerings of a transmutation
theory of his own;[1] so that he is equally exposed to all the
philosophical objections advanced by Agassiz, and to most of those
urged by the other American critics, against Darwin himself.

Proposing now to criticize the critics, so far as to see what their
most general and comprehensive objections amount to, we must needs
begin with the American reviewers, and with their arguments adduced to
prove that a derivative hypothesis _ought not to be true_, or is not
possible, philosophical, or theistic.

It must not be forgotten that on former occasions very confident
judgments have been pronounced by very competent persons, which have
not been finally ratified. Of the two great minds of the seventeenth
century, Newton and Leibnitz, both profoundly religious as well as
philosophical, one produced the theory of gravitation, the other
objected to that theory that it was subversive of natural religion.
The nebular hypothesis--a natural consequence of the theory of
gravitation and of the subsequent progress of physical and
astronomical discovery--has been denounced as atheistical even down to
our own day. But it is now largely adopted by the most theistical
natural philosophers as a tenable and perhaps sufficient hypothesis,
and where not accepted is no longer objected to, so far as we know, on
philosophical or religious grounds.

The gist of the philosophical objections urged by the two Boston
reviewers against an hypothesis of the derivation of species--or at
least against Darwin's particular hypothesis--is, that it is