Driesch’s conclusions continue to advance, led steadily onwards by his experimental studies. In the “Maschinentheorie des Lebens,”(100) he attacks his own earlier theories with praiseworthy determination, and remorselessly pursues them to the monstrous conclusions to which they lead, and shows that they necessarily perish because of these. He had previously declared, at first emphatically, later with hesitation (we have already seen why), that every single vital process is of a physico-chemical kind, on the basis of a given “structure” of living beings. But now he considers the living organism as itself a result of vital processes—that is, of development. If this also is to be explained mechanically (as physico-chemical processes based on material structure), then the ovum must possess _in parvo_ this infinitely fine structure, by virtue of which it fulfils its own physiological processes of maintenance, and also becomes the efficient cause of the subsequent development. It must bear the type of the individual and of the species, as a rudiment (or primordium) within its own structure. Every specific type must, however, according to the theory of descent, be derived through an endless process of evolution, by gradual stages, from some primitive organism. Just as in the mechanical becoming of the individual organism, so the primitive protovum must also be extraordinarily intricate and complex in its organisation if it is to give rise to all the processes of evolution and development involved in the succeeding ontogenies, phylogenies, regenerations, and so forth. This is a necessary conclusion if the machine-theory be correct, and if we refuse to admit that vital phenomena are governed by specific laws. This consequence is monstrous, and the theory of the tectonists therefore false. But if it be false, what then?
Driesch answers this question in the books published in subsequent years.(101) In these he attains his final standpoint, and makes it more and more secure. The “machine-theory,” and all others like it, are now definitely abandoned. They represent the uncritical dogmatism of a materialistic mode of thought, which binds all phenomena to substance, and refuses to admit any immaterial or dynamic phenomena. The alleged initial structure is nowhere to be found. The pursuit of things into the most minute details leads to no indication of it. The chromatin, in which the most important vital processes have their basis, is very far from having this machine-like structure; it is homogeneous. The formation of the skeleton, for instance, of a Plubeus larva is due to migratory spontaneously moving cells (comparable to the leucocytes of our own body, whose migrations and activities remind one much more of a social organism than of a machine). The organism arises, not from mechanical, but from “harmoniously-equipotential systems”: that is to say, from systems every element of which has equal functional efficiency; so that each individual part bears within itself in an equal degree the potentiality of the whole—an impossibility from the mechanical point of view.