KANT AND EVOLUTION 547 
author’s death, the “Protogea” of Leibniz was published. In this 
Leibniz contended, on grounds now familiar enough, that the earth 
must have originally been in a fluid and intensely heated state; that 
through the cooling of the surface a solid crust was formed and the 
viscous fiery substance of the globe concentrated in the interior; that 
the present earth-structure is due to the successive action in the past 
of fire (fusion) and water (sedimentation) ; and that the existence of 
fossils testifies to the extinction of once flourishing species of animals, 
in consequence of modifications of the earth’s surface due to one or the 
other of these agencies. 
For comparison with the hypotheses of his precursors and succes- 
sors, Kant’s own scheme of cosmogony must now be indicated in its 
more essential features. He assumes for a starting point a “state of 
nature which is the very simplest that could follow upon nonentity,” 
namely, a chaos in which all the matter in the universe was scattered 
throughout infinite space. It somehow “ filled” the whole of that 
space, and yet its component particles were infinitely more diffused than 
now; Kant expressly declares that space was once “ full,” and is now 
“empty,” except for the actual celestial bodies. The original particles 
were not all alike; they differed in “specific density and force of 
attraction.” Consequently, when the universe is once permitted to be- 
gin active business, “ the scattered elements of the denser sort, by virtue 
of their attraction, gather together out of the space surrounding them 
all the matter of less specific gravity; these elements in turn, with the 
material which has united with them, collect in points where the par- 
ticles of a yet denser kind are found”; and so on. 
If we follow in imagination this process by which nature fashions itself 
into form throughout the whole extent of chaos, we easily perceive that the 
sole result of this process would consist finally in the agglomeration of divers 
masses which, when their formation was complete, would be forever at rest 
and unmoved. 
Fortunately, nature has other forces at her command; besides gravi- 
tation, there is also operative a force of repulsion, which shows itself 
“especially when matter is decomposed into fine particles.” By this 
force the elements, “as they fall towards the attracting body are de- 
flected by one another and have their perpendicular fall converted into 
a movement of revolution.” Having indicated the two general working 
principles of his cosmical mechanics, Kant now judiciously leaves the 
problem of the genesis of a universe, and turns somewhat abruptly to 
the simpler problem of the formation of our solar system, from the 
solution of which “ we shall be able by analogy to infer a similar mode 
of origination in the case of the larger world-systems.” 
The lesser process, as Kant conceives it, may be said to fall into 
four stages: (1) The formation of the nucleus of a sun. There is 
formed at the point of maximum attraction of a given region of space, 
“a body which, so to say, grows from an infinitely small germ, at first 
