To admit this view is, as it seems to me, to reject a real for an unreal, or at least for an unknown, cause. It makes the work of God a mere mockery and deception; I would almost as soon believe with the old and ignorant cosmogonists, that fossil shells had never lived, but had been created in stone so as to mock the shells now living on the sea-shore.

In this quotation, from Chapter V, Darwin takes on naturalists who believe that each species was independently created. He has just presented evidence that species must have descended from one another. Specifically, he has shown that color patterns appearing in varieties of horses often mimic the color patterns of zebras and horses, which illustrates that all may have descended from the same parent species. Darwin says that some naturalists will not believe this claim and will argue that variations occur in all species and do not prove that one species descended from the other. In this quotation, Darwin challenges the scientific validity of these dissenters’ claims; he provides scientific reasoning, while they provide none. The last sentence of this passage suggests that it is ridiculous to claim that species similarities are mere coincidence. By calling these similarities “the work of God,” Darwin also challenges the notion that only the theory of independent creation acknowledges the existence of a divine power. Natural selection, Darwin implies, may also be the work of a higher power. To ignore his theory may be as much an affront to God as some say the theory itself is.