cannot perceive that Darwin's theory brings in any new kind of
scientific difficulty, that is, any with which philosophical
naturalists were not already familiar.

Since natural science deals only with secondary or natural causes, the
scientific terms of a theory of derivation of species--no less than of
a theory of dynamics--must needs be the same to the theist as to the
atheist. The difference appears only when the inquiry is carried up to
the question of primary cause--a question which belongs to philosophy.
Wherefore, Darwin's reticence about efficient cause does not disturb
us. He considers only the scientific questions. As already stated, we
think that a theistic view of Nature is implied in his book, and we
must charitably refrain from suggesting the contrary until the
contrary is logically deduced from his positions. If, however, he
anywhere maintains that the natural causes through which species are
diversified operate without an ordaining and directing intelligence,
and that the orderly arrangements and admirable adaptations we see all
around us are fortuitous or blind, undesigned results,--that the eye,
though it came to see, was not designed for seeing, nor the hand for
handling,--then, we suppose, he is justly chargeable with denying, and
very needlessly denying, all design in organic Nature; otherwise we
suppose not. Why, if Darwin's well-known passage about the
eye[3]--equivocal or unfortunate though some of the language be--does
not imply ordaining and directing intelligence, then he refutes his
own theory as effectually as any of his opponents are likely to do. He
asks,--

"May we not believe that"--under variation proceeding long enough,
generation multiplying the better variations times enough, and
natural selection securing the improvements--"a living optical