156 FRAGMENTS OF SCIENCE. 



be quite as conclusive. Lichtenberg, indeed, showed 

 that the very thing to be proved was inevitably postu- 

 lated in the first two words, * I think; ' and it is plain 

 that no inference from the postulate could, by any 

 possibility, be stronger than the postulate itself. 



But Descartes deviated strangely from the idealism 

 implied in his fundamental principle. He was the 

 first to reduce, in a manner eminently capable of bear- 

 ing the test of mental presentation, vital phenomena to 

 purely mechanical principles. Through fear or love, 

 Descartes was a good churchman; he accordingly re- 

 jected the notion of an atom, because it was absurd to 

 suppose that God, if He so pleased, could not divide an 

 atom; he puts in the place of the atoms small round 

 particles, and light splinters, out of which he builds the 

 organism. He sketches with marvellous physical in- 

 sight a machine, with water for its motive power, which 

 shall illustrate vital actions. He has made clear to his 

 mind that such a machine would be competent to carry 

 on the processes of digestion, nutrition, growth, res- 

 piration, and the beating of the heart. It would be 

 competent to accept impressions from the external 

 sense, to store them up in imagination and memory, to 

 go through the internal movements of the appetites 

 and passions, and the external movements of the limbs. 

 He deduces these functions of his machine from the 

 mere arrangements of its organs, as the movement of a 

 clock, or other automaton, is deduced from its weights 

 and wheels. ' As far as these functions are concerned/ 

 he says, ' it is not necessary to conceive any other vege- 

 tative or sensitive soul, nor any other principle of 

 motion or of life, than the blood and the spirits agi- 

 tated by the fire which burns continually in the heart, 

 and which is in no wise different from the fires existing 

 in inanimate bodies/ Had Descartes been acquainted 



