420 RISE AND PROGRESS OF 



constituted the act of respiration ; and as this vital function was 

 supposed to be produced by the influence of the moon, so its other 

 living energies were dependant on the configurations of the planets. 

 In the Harmonies of the celestial motions, he assigns to Jupiter 

 and Saturn the bass, to Mars the tenor, the counter-tenor to the 

 Earth and Venus, and the treble to Mercury. 



The cosmical system of Des Cartes is too important in the 

 history of science to be passed over without notice, although it 

 seems to have been but a refinement on the doctrine of Eudoxus, 

 and was as remote from real existence. Kepler, we have seen, 

 had endowed the great bodies of the universe with vital powers, 

 and chained them together, in their wanderings through space, by 

 the ties of animal sympathy. The astrologers of the day borrowed 

 from the region of spirit itself, and, by a beautiful fiction, assigned 

 to each planet its guardian angel, whose office it was to guide its 

 career through the trackless void. Des Cartes was the first who, 

 with any show of plausibility, attempted to reduce the whole to 

 physical principles, and to derive the phenomena of the material 

 world from the fundamental properties of body. Matter, accord- 

 ing to this ingenious philosopher, fills all space ; and its parts are 

 endued with motion in every possible direction. By the combina- 

 tion of these infinitely varied motions, matter is supposed to be 

 continually deflected from its rectilinear course ; and thus at length 

 to form itself into vortices, in which the denser bodies of the 

 universe floated, and of whose motion they partook. In this 

 manner the earth and planets were supposed to be borne round the 

 sun, in the vortex of the solar system : and each planet itself was 

 the centre of a lesser vortex, which carried its secondaries. Such 

 was the system which preceded the theory of universal gravitation. 

 Mankind looked up with wonder on the symmetrical fabric 

 which the enchanter's wand had raised, and they examined not 

 too narrowly into its foundations ; but a mightier wizard soon 

 after came upon the scene, and the rod of Aaron swallowed the 

 rod of the Egyptian. 



The actual contributions of Des Cartes to mechanical science 

 are inconsiderable. He was an a priori philosopher, in the strictest 

 sense of the word; and in the barrenness of that philosophy 

 aided as it was by powerful talents, and by the force of these 

 talents gaining an ascendancy, which for a time closed men's eyes 

 to the truth we have, perhaps, as striking a proof as could be 



