Transformism makes no pretence to account for the origin of life, whether animal or vegetable. Living things must exist before any question arises as to their transmutation. But, given the existence of life, Transformists undertake in the first place to show that Organic Evolution has, as a matter of fact, occurred, and is still in process of occurrence; and secondly, to exhibit the manner in which this process is actually worked out. As to the first point, all Transformists, whether Darwinians or others, are necessarily at one, for the fact of Evolution is equally essential for every explanation of its method. It is when they come to explain in what manner evolutionary transformations have been wrought that Transformists divide themselves into various schools, each of which relies upon some particular factor to furnish the required explanation. Thus besides Darwinians pure and simple, there are neo-Darwinians, Lamarckians, neo-Lamarckians, Weismannists, and others, ascribing the results to physiological selection, sexual-selection, or other forces, rather than natural selection. Of such systems, however, excepting only Darwinism, it will be unnecessary to speak in particular. The great fundamental question is whether genetic Evolution be really established as a fact,--which, as has been said, equally affects them all--and if it be advisable to treat more in detail of Darwinism, it is not because this does not hold good of it as of the rest--but because this particular system has obtained such a position, is so much in the mouths of men, and has been made the basis of so many and such far-reaching consequences, that it is impossible to pass it by.
Much the same may indeed be said even of the assumed fact of Organic Evolution underlying all Transformist theories. This does not affect the fundamental problems with which we are concerned, and leaving untouched, as it does, the question of the origin of Life it makes even less pretence than the cosmic-nebular hypothesis just spoken of to trace the operations of Nature to their ultimate source. It might therefore appear superfluous to devote to it so much attention as, if treated at all, it must needs demand.
But, whatever may thus appear from the point of view of strict logic, it is abundantly evident that in common estimation the assumed fact of Organic transformation is the foundation-stone of Evolutionary systems of every kind. And not unnaturally; for here at last we have something with which Science can deal, strictly according to her own methods. If she knows, and can know, nothing from actual observation concerning the first beginnings of matter, of the cosmic nebula, or of life, it is quite otherwise with the history of living things since they first appeared, and with the phenomena of life as it exists and is propagated. Here are questions which are strictly scientific, forming the subject-matter of Palæontology and Biology, and these Sciences supplemented by others, such as Geology, Physical Geography, and Astronomy, furnish a mass of evidence bearing upon the subject of Organic Evolution. When therefore the great majority of men of Science, declare that the fact of genetic Transformism is established beyond the possibility of doubt, Evolutionists find themselves supplied with a plausible foothold on which to stand and rest their fulcrum, while, like Archimedes, they proceed to move the world.