These views are more fully developed in the theory of dominants expounded in Reinke’s later work, “Die Welt as Tat” (after what has been said the meaning of the title will be self-evident), and in his “Theoretische Biologie.”(97) Very vigorous and convincing are the author’s objections to the naturalistic theories of organic life, especially to the “self-origin” of the living, or spontaneous generation. In all vital processes we must reckon with a “physiological _x_,” which cannot be eliminated, which gives to life its unique and underivable character. There are “secondary forces,” “superforces,” “dominants,” which bring about what is peculiar in vital functions and direct their processes. “Vitalism” in the strict sense is thus here also rejected. The machine-theory is held valid. There are “dominants” even in our tools and utensils, in our hammer and spoon, and the “operation” of these cannot be explained merely physico-chemically, but through the dominants of the form, structure and composition, with which they have been invested by intelligence. The association with the views of the tectonists is so far quite apparent. But the idea of “dominants” soon broadens out. We find dominants of form-development, of evolution, and so on. What were at first only peculiarities of structure and architecture have grown almost unawares into dynamic principles of form which have nothing more to do with the mechanical theory, and which, because of their dualistic nature, result in conclusions and modes of explanation which can hardly be called very useful. The lines along which the idea has developed are intelligible enough. It started originally from that of the organism as a finished product, functioning actively, especially in its metabolism. Here the comparison with a steam engine with self-regulators and automatic whistles is admissible, and one may speak of dominants in the sense of mechanical dominants. But the idea thus started was pressed into general service. And thus arose dominants of development, of morphogenesis, even of phylogenetic evolution (“phylogenetic evolution-potential”). New dominants are added, and the theory advances farther and farther from the “machine theory,” becomes ever more enigmatical, and more vitalistic. The Constructive Work of Driesch.