True, mathematical infinites are in some respects different from metaphysical infinites; but it is the former that belong to this argument, since the supposed infinite succession of organic beings forms a mathematical series.
An acute writer in our own country, however, has recently attempted to show that "there can be no number actually infinite, and therefore no infinite number of generations."[11] That the mathematician cannot actually present before us the whole of an infinite series, is indeed most certain; for such, power belongs only to an Infinite Being. But does the fact that man's faculties are limited, prove that an arithmetical process cannot be carried on from eternity to eternity? Because man cannot put upon paper the series of numbers representing the miles in infinite space, or the hours in infinite duration, is there, therefore, no such thing as infinite space, or infinite duration? Certainly not, if this reasoning be correct.
In spite, however, of such mathematical metaphysics, is it not an intelligible statement of the atheist, when he says of any generation of men and animals in past time, that there was another that preceded it and unless you have matter-of-fact proof to the contrary, how will you disprove this assertion? You may show him that practically he can never exhibit a series, even of numbers, extending eternally backward; but he may, in return, challenge you to put your finger upon the first link of the chain of organic nature. If you attempt it, he will reply that other links preceded the one you have named, and that, as far as you choose to run backward, he can go farther; in other words, by the very supposition which he makes, he excludes a beginning to organic nature, and, therefore, all reasoning which assumes such a beginning is of no force against his conclusions. If a series which may thus be extended indefinitely backward be not infinite in a metaphysical sense, it is to common sense.
Let me not be thought to be an advocate in any sense for the unsupported notion of an infinite series of organic beings. But the question is, whether those who, in spite of common sense, have maintained this opinion, have been fairly refuted by such metaphysical evasions as I have quoted. The truth is, that, in order to end this dispute, the Theist needs to bring forward at least one example in which the commencement of some race of animals can be fairly pointed out; and I know not where such an example can be found, save in the Bible and geology.