So the issue between the skeptic and the theist is only the old one, long ago argued out—­namely, whether organic Nature is a result of design or of chance.  Variation and natural selection open no third alternative; they concern only the question how the results, whether fortuitous or designed, may have been brought about.  Organic Nature abounds with unmistakable and irresistible indications of design, and, being a connected and consistent system, this evidence carries the implication of design throughout the whole.  On the other hand, chance carries no probabilities with it, can never be developed into a consistent system, but, when applied to the explanation of orderly or beneficial results, heaps up improbabilities at every step beyond all computation.  To us, a fortuitous Cosmos is simply inconceivable.  The alternative is a designed Cosmos.

It is very easy to assume that, because events in Nature are in one sense accidental, and the operative forces which bring them to pass are themselves blind and unintelligent (physically considered, all forces are), therefore they are undirected, or that he who describes these events as the results of such forces thereby assumes that they are undirected.  This is the assumption of the Boston reviewers, and of Mr. Agassiz, who insists that the only alternative to the doctrine, that all organized beings were supernaturally created just as they are, is, that they have arisen spontaneously through the omnipotence of matter.[III-11]

As to all this, nothing is easier than to bring out in the conclusion what you introduce in the premises.  If you import atheism into your conception of variation and natural selection, you can readily exhibit it in the result.  If you do not put it in, perhaps there need be none to come out.  While the mechanician is considering a steamboat or locomotive-engine as a material organism, and contemplating the fuel, water, and steam, the source of the mechanical forces, and how they operate, he may not have occasion to mention the engineer.  But, the orderly and special results accomplished, the why the movements are in this or that particular direction, etc., is inexplicable without him.  If Mr. Darwin believes that the events which he supposes to have occurred and the results we behold were undirected and undesigned, or if the physicist believes that the natural forces to which he refers phenomena are uncaused and undirected, no argument is needed to show that such belief is atheism.  But the admission of the phenomena and of these natural processes and forces does not necessitate any such belief, nor even render it one whit less improbable than before.