THE BELFASl ADDRESS. 459 



SECTIOK 4. In the seventeenth century Bacon and 

 Descartes, the restorers of philosophy, appeared in suces- 

 sion. Differently educated and endowed, their philosophic 

 tendencies were different. Bacon held fast to Induction, 

 believing firmly in the existence of an external world, and 

 making collected experiences the basis of all knowledge. 

 The mathematical studies of Descartes gave him a bias 

 toward deduction; and his fundamental principle was 

 much the same as that of Protagoras, who made the indi- 

 vidual man the measure of all things. " I think, therefore 

 I am," said Descartes. Only his own identity was sure to 

 him; and the full development of this system would have 

 led to an idealism, in which the outer world would have 

 been resolved into a mere phenomenon of consciousness. 

 Gassendi, one of Descartes' contemporaries, of whom we 

 shall hear more presently, quickly pointed out that the 

 fact of personal existence would be proved as well by refer- 

 ence to any other act, as to the act of thinking. I eat, 

 therefore I am, or I love, therefore I am, would be quite as 

 conclusive. Lichtenberg, indeed, showed that the very 

 thing to be proved was inevitably postulated 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 im- 

 plied in his fundamental principle. He was the first to 

 reduce, in a manner eminently capable of bearing the test 

 of mental presentation, vital phenomena to purely mechan- 

 ical principles. Through fear or love, Descartes was a 

 good churchman; he accordingly rejected 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 marvel- 

 ous physical insight 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, 

 respiration, 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 



