212 ANIMAL AUTOMATISM. [LECT. 



appropriate feeling. This is the physical 

 mechanism of memory. 



Descartes imagined that the pineal body (a curious 

 appendage to the upper side of the brain, the function 

 of which, if it have any, is wholly unknown) was the 

 instrument through which the soul received impres- 

 sions from, and communicated them to, the brain. 

 And he thus endeavours to explain what happens 

 when one tries to recollect something : 



"Thus when the soul wills to remember anything, this 

 volition, causing the [pineal] gland to incline itself in different 

 directions, drives the [animal] spirits towards different regions of 

 the brain, until they reach that part in which are the traces, 

 which the object which it desires to remember has left. These 

 traces are produced thus : those pores of the brain through 

 which the [animal] spirits have previously been driven, by reason 

 of the presence of the object, have thereby acquired a tendency 

 to be opened by the animal spirits which return towards them, 

 more easily than other pores, so that the animal spirits, imping- 

 ing on these pores, enter them more readily than others. By 

 this means they excite a particular movement in the pineal 

 gland, which represents the object to the soul, and causes it to 

 know what it is which it desired to recollect." 1 



That memory is dependent upon some condition 

 of the brain is a fact established by many considera- 

 tions among the most important of which are the 

 remarkable phenomena of aphasia. And that the 

 condition of the brain on which memory depends, is 

 largely determined by the repeated occurrence of that 

 condition of its molecules, which gives rise to the 

 idea of the thing remembered, is no less certain. 



1 " Les Passions de Time," xlii. 



