333 LAY SERMONS, ADDRESSES, AND REVIEWS. [xiv. 



And thus we are led, in another way, to lose spirit 

 in matter. 



In truth, Descartes' physiology, like the modern physi- 

 ology of which it anticipates the spirit, leads straight to 

 Materialism, so far as that title is rightly applicable to the 

 doctrine that we have no knowledge of any thinking sub- 

 stance, apart from extended substance ; and that thought 

 is as much a function of matter as motion is. Thus we 

 arrive at the singular result that, of the two paths opened 

 up to us in the " Discourse upon Method," the one 

 leads, by way of Berkeley and Hume, to Kant and 

 Idealism; while the other leads, by way of De La 

 Mettrie and Priestley, to modern physiology and Mate- 

 rialism. 1 Our stem divides into two main branches, 

 which grow in opposite ways, and bear flowers which 

 look as different as they can well be. But each branch 

 is sound and healthy, and has as much life and vigour 

 as the other. 



If a botanist found this state of things in a new plant, 

 I imagine that he might be inclined to think that his tree 

 was monoecious — that the flowers were of different sexes, 

 and that, so far from setting up a barrier between the 

 two branches of the tree, the only hope of fertility lay in 

 bringing them together. I may be taking too much of a 

 naturalist's view of the case, but I must confess that this 

 is exactly my notion of what is to be done with meta- 

 physics and physics. Their differences are comple- 

 mentary, not antagonistic ; and thought will never be 

 i'ompletely fruitful until the one unites with the other. 



1 Bouillier, into whose excellent " History of the Cartesian Philosophy n 

 I had not looked when this passage was written, says, very justly, that Descartes 

 " a merite le titre de pere de la physique, aussi bien que celui de pere de la 

 metaphysique moderne " (t. i. p. 197). See also Kuno Fischer's " Geschichte 

 der neuen Philosophic," Bd. i. ; and the very remarkable work of Lange, 

 " Geschichte des Materialismus." — A good translation of the latter would be 

 a great seryice to philosophy in England. 



