in proportion to the cube.[1] Kant seeks, by reasonings both obscure and peculiar, to establish an a priori necessity that these two forces—emanating from identical points and perfectly analogous save in the direction of the motion of the external particles they affect—should yet differ in the ratio in which their potency decreases with distance. But in the "Universal Natural History" the disciple of Newton bases no calculations, such as could be compared with the actual positions and densities of the heavenly bodies, upon this quantitative formula—of which, possibly, he had not yet bethought himself. In fact, in his cosmogony he wholly fails to indicate even an approximate law of the action of repulsive force. When the plot of the world-story threatens to come to a standstill or to issue in a hopeless entanglement, "repulsion" like a deus ex machina appears upon the scene to set things right and ensure a happy ending. Precisely the same particles, under what (so far as one can judge from Kant's language) might be similar physical conditions, and at approximately equal distances, figure now as attracting, now as repelling, one another, as the exigencies of the hypothesis require. That a theorist who improvised laws of dynamics in so easy-going a manner proves to have anticipated a very recent conception of planetary evolution, must, I think, be regarded rather as evidence of good luck than of scientific good management.
What, now, was, for Kant himself, the bearing of his doctrine of cosmic evolution upon biology? Descartes, holding the theory of animal automatism, had undoubtedly regarded the formation of organisms as part of that mechanical process of the redistribution of matter which also explained the formation of suns and planets. Such a view was not necessarily equivalent to a belief in the transformation of species. There is no necessary logical connection (though there is a natural affinity) between a mechanistic physiology and transformism—any more than between a vitalistic physiology and the doctrine of the fixity of species. Thus the question concerning the relation of cosmic evolutionism to biology is merely the genetic form of the issue of vitalism versus mechanism; in it the problems of the theory of descent need not be directly implicated. Upon this question a view current in Kant's time was that the gradual generis of inorganic things might well be ex-
- ↑ Kant's conception of "repulsive force" is used by him in the "Physical Monadology" primarily to explain the impenetrability of bodies (for which he supposes that a special force must be posited). But it is not identical with impenetrability; it is explicitly represented by him as a force acting in distans. In the "Universal Natural History" it is rather to the phenomena of solutions and the expansion of gases that Kant points as empirical evidence of the existence of such a force. Newton ("Optics," Bk. III., Q. 31) had made a like inference from the same phenomena; but he did not write, as Kant did, seventeen years after D. Bernouilli had propounded the kinetic theory of gases. And it is impossible to imagine Newton deducing a cosmogony by the use of a conception so loose and quantitatively indefinite as is Kant's conception of repulsive force in the "Universal Natural History."
