MEMORY. 



656 



Fig. 45. 



the occasion arises ; when it is slow, resuscitation comes 

 after delay. But be the recall prompt or slow, the condi- 

 tion which makes it possible at all (or in other words, the 

 * retention ' of the experience) is neither more nor less than 

 the brain-paths which associate the experience with the 

 occasion and cue of the recall. When slumbering, these paths 

 are the condition of retention ; ivhen active, they are the coiwii- 

 Hon of recall. 



A simple scheme will now make the whole cause of 

 memory plain. Let n be a past 

 event ; o its ' setting ' (concomi- 

 tants, date, self present, warmth 

 and intimacy, etc., etc., as already 

 set forth) ; and m some present 

 thought or fact which may appro- 

 priately become the occasion of its 

 recall. Let the nerve-centres, ac- 

 tive in the thought of m, n, and o, 

 be represented by M, N, and O, re- 

 spectively ; then the existence of the paths M — N and N — O 

 will be the fact indicated by the phrase ' retention of the 

 event n in the memory,' and the excitement of the brain along 

 these paths will be the condition of the event w's actual re- 

 call. The retention of n, it will be observed, is no mysterious 

 storing up of an * idea ' in an unconscious state. It is not a 

 fact of the mental order at all. It is a purely physical phe- 

 nomenon, a morphological feature, the presence of these 

 ' paths,' namely, in the finest recesses of the brain's tissue. 

 The recall or recollection, on the other hand, is a psycho- 

 physical j)lienomenou, with both a bodily and a mental side. 

 The bodily side is the functional excitement of the tracts 

 and paths in question ; the mental side is the conscious 

 vision of the past occurrence, and the belief that we ex- 

 perienced it before. 



These habit-worn paths of association are a clear ren- 

 dering of what authors mean by 'predispositions,' 'vestiges,' 

 ' traces,' etc., left in the brain by past exjDerience. Most 

 writers leave the nature of these vestiges vague ; few think 



