xiv.J ON DESCARTES' "DISCOURSE" 333 



the central office. Moreover, respiration and other sncli actions as are 

 natural and usual in the body, and which depend on the course of the 

 spirits, are like the movements of a clock, or of a mill, which may bo 

 kept up by the ordinary ilow of the water. 



"The external objects which, by their mere presence, act upon the 

 organs of the senses ; and which, by this means, determine the cor- 

 poral machine to move in many different ways, according as the parts 

 of the brain are arranged, are like the strangers who, entering into 

 some of the grottoes of these waterworks, unconsciously cause the 

 movements which take place in their presence. For they cannot enter 

 without treading upon certain planks so arranged that, for example, if 

 they approach a bathing Diana, they cause her to hide among the 

 reeds ; and if they attempt to follow her, they see approaching a 

 Neptune, who threatens them with his trident ; or if they try some 

 other way, they cause some monster who vomits water into their 

 faces, to dart out ; or like contrivances, according to the fancy of the 

 engineers who have made them. And lastly, when the rational soul is 

 lodged in this machine, it will have its principal seat in the brain, and 

 will take the place of the engineer, who ought to be in that part of 

 the works with which all the pipes are connected, when he wishes to 

 increase, or to slacken, or in some way to alter, their movements." x 



And again still more strongly : — 



" All the functions which I have attributed to this machine (the 

 body), as the digestion of food, the pulsation of the heart and of 

 the arteries ; the nutrition and the growth of the limbs ; respiration, 

 wakefulness, and sleep ; the reception of light, sounds, odours, llavours, 

 heat, and such like qualities, in the organs of the external senses ; the 

 impression of the ideas of these in the organ of common sense and in 

 the imagination ; the retention, or the impression, of these ideas on the 

 memory ; the internal movements of the appetites and the passions ; 

 and lastly, the external movements of all the limbs, which follow so 

 aptly, as well the action of the objects which are presented to the 

 senses, as the impressions wiiich meet in the memory, that they 

 imitate as nearly as possible those of a real man : 2 I desire, I say, 

 that you should consider that these functions in the machine naturally 

 proceed from the mere arrangement of its organs, neither more nor 

 less than do the movements of a clock, or other automaton, from that 



1 "Traite de momme" (Cousin's Edition), p. 347. 



2 Descartes pretends that he does not apply his views to the human body, 

 but only to an imaginary machine which, if it could be constructed, would do 

 all that the human body does ; throwing a sop to Cerberus unworthily ; and 

 Uselessly, because Cerberus was by no means stupid enough to swallow it. 



