Those whose protests we have hitherto been considering have not added to their criticism of the [pg 254] mechanical theory any positive contribution of their own, or at least they give nothing more than very slight hints pointing towards a psychical theory. But there are others who have sought to overcome the mechanical theory by gaining a deeper grasp of the nature of “force” in general. Their attempts have been of various kinds, but usually tend in one direction, which can perhaps be most precisely and briefly indicated through Lloyd Morgan's views, as summed up, for instance, in his essay on “Vitalism.”94 In the beginning of biological text-books, we usually find (he says) a chapter on the nature of “force,” but it is “like grace before meat”—without influence on quality or digestion. Yet this problem must be cleared up before we can arrive at any understanding of the whole subject. In all attempts at “reducing to simpler terms,” it must be borne in mind that “force” reveals its nature in ever higher stages, of which every one is new. Even cohesion cannot be reduced to terms of gravitation, nor the chemical affinities and molecular forces to something more primitive. They are already something “outside the recognised order of nature.” In a still higher form force is expressed in the processes of crystallisation. At the formation of the first crystal there came into action a directing force of the same kind as the will of the sculptor at the making of the Venus of Melos. This new element, which intervenes every time, Lloyd Morgan regards, with Herbert [pg 255] Spencer (“Principles of Biology”), as “due to that ultimate reality which underlies this manifestation, as it underlies all other manifestations.” There can be no “understanding” in the sense of “getting behind things”: even the actions of “brute matter” cannot be “understood.” The play of chance not only does not explain the living; it does not even explain the not-living. But life in particular can neither be brought into the cell from without, nor be explained as simply “emerging from the co-operation of the components of the protoplasm,” and it is “in its essence not to be conceived in physico-chemical terms,” but represents “new modes of activity in the noumenal cause,” which, just because it is noumenal, is beyond our grasp. For only phenomena are “accessible to thought.”

Among the biologists who concern themselves with deeper considerations, Oscar Hertwig,95 the Director of the Anatomical Institute at Berlin, has expressed ideas similar to those we have been discussing, little as this may seem to be the case at first sight. He desires to oust the ordinary mechanism, so to speak, by replacing it by a mechanism of a higher order, and in making the attempt he examines and deepens the traditional ideas of causality and “force,” and defines the right and wrong of the quantitative-mathematical interpretation of nature in general, and of mechanics in particular. He [pg 256] follows confessedly in Lotze's path, not so much in regard to that thinker's insistence upon the association of the causal and the teleological modes of interpretation, as in modifying the idea of causality. O. Hertwig puts forward his own theories with special reference to those of W. Roux, the founder of the new “Science of the Future”—the mechanical, and therefore only scientific theory of development, which no longer only describes, but understands and causally explains phenomena (“Archiv fÜr Entwicklungsmechanik”). There are two kinds of mechanism (Hertwig says): that in the higher philosophical sense, and that in the purely physical sense. The former declares that all phenomena are connected by a guiding thread of causal connection and can be causally explained. As such, its application to the domain of vital phenomena is justifiable and self-evident. But it is not justifiable if cause be simply made identical with and limited to “force,” if the causal connection be only admitted in the technical sense of the transference and transformation of energy, and if, over and above, it is supposed to give an “explanation,” in the sense of an insight into things themselves. Even mechanics is (as Kirchoff maintained) a “descriptive” science. Hertwig agrees with Schopenhauer and Lotze in regarding every primitive natural “force” as unique, not reducible to simpler terms, but qualitatively distinct,—a “qualitas occulta,” capable not of physical but only of metaphysical explanation. And thus his conclusions imply rejection of mechanism in the cruder [pg 257] sense. As such, it has only a very limited sphere of action in the realm of the living. The history of mechanical interpretations is a history of their collapse. The attempt to derive the organic from the inorganic has often been made. But no such attempts have held the field for long. We can now say with some reason that “the gulf between the two kingdoms of nature has become deeper just in proportion as our physical and chemical, our morphological and physiological knowledge of the organism has deepened.” Mach's expression “mechanical mythology,” is quoted, and then a fine passage on the insufficiency of the mathematical view of things in general concludes thus: “Mathematics is only a method of thought, an excellent tool of the human mind, but it is very far from being the case that all thought and knowledge moves in this one direction, and that the content of our minds can ever find exhaustive expression through it alone.”

In his “Theory of Dominants,”96 Reinke, the botanist of Kiel, has attempted to formulate his opposition to the physico-chemical conception of life into a vitalistic theory of his own. Among biologists who confess themselves supporters of the mechanical theory, there are some who expressly reject explanations in terms of [pg 258] chemical and physical principles, and emphasise, more energetically than others, that these can only give rise to vital phenomena and complex processes of movement, on the basis of a most delicately differentiated structure and architecture of the living substance in its minute details, and from the egg onwards. They have created the strict “machine theory,” and they may be grouped together as the “tectonists.” “A watch that has been stamped to pieces is no longer a watch.” Thus the merely material and chemical is not the essential part of the living; it is the tectonic, the machinery of structure that is essential. The fundamental idea in this position is precisely that of Lotze. It is not a “mystical,” vital principle, that sets up, controls, and regulates the physical and chemical processes within the developed or developing organism. They receive their direction and impulse through the fact that they are associated with a given peculiar mechanical structure. This theory certainly contains all the monstrosities of preformation in the germ, the mythologies of the infinitely small, and it suffers shipwreck in ways as diverse as the number of its sides and parts. But it has the merit of clearly disclosing the impossibilities of purely chemical explanations. Reinke's “Theory of Dominants” started from such tectonic conceptions, and so originally did Driesch's Neovitalism, of which we shall presently have to speak.

Reinke's theory has gone through several stages of [pg 259] development. At first its general tenor was as follows: Every living thing is typically different from everything that is not living. What explains this difference? Certainly not the hypothesis of vital force, which is far from being clear. The idea that forces of a psychic nature are inherent in the organism is also rejected. The illustration of a watch helps us to understand. The impelling force in it is certainly not merely the ordinary force of gravity or the general elasticity of steel. The efficacy of simple forces such as these can be increased in infinite diversity by the “construction of the apparatus” in which they operate. Life is the function of a quite unique, marvellously complex, inimitable combination of machines. If these be given, the most complex processes fulfil themselves of necessity and without the intervention of special vital forces. But how can they be “given”? The sole analogy to be found is the making of real machines, artificial products as distinguished from fortuitous products. They cannot be made without the influence and activity of intelligence. To explain the incomparably more ingenious and complex vital machine as due to a fortuitous origin and collocation of its individual parts would be more absurd than it would be to think of a watch being made in this way. The dominance of a creative idea cannot but be recognised. An intelligent natural force which is conscious of its aims and calculates its means must be presupposed, if we are really to [pg 260] satisfy our sense of causality. It is a matter of personal conviction whether we find this force in “God” or in the “Absolute.”

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, [pg 261] 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.