THE ORIGIN OF MAN 263 



law of gravitation. The pain produced by the stroke 

 of the apple, together with all the other sensations 

 aroused by the external world which Newton ever ex- 

 perienced,werenot equivalent to the process of reason- 

 ing by which he deduced the law. The faculty with 

 which we reason is not sensation. 



Ten years ago we saw an object : an image of the 

 object was formed on the retina of the eye, and the 

 mind perceived the image and recorded it. To-day 

 we remember that we saw the image ten years ago. 

 How can we explain the act of remembering? The 

 act of remembering is not simply the reproduction of 

 a former mental condition, but it is also a recognition 

 of the fact that the former mental condition existed. 

 If the original impression made by seeing the object 

 could be regarded as simply a sensation, still the sub- 

 sequent act of remembering involves more than 

 sensation. 



If we claim that. the sight of the object left a mate- 

 rial record on the brain, and that this material record 

 is memory, we are in total darkness. Granted that a 

 material record is kept, what reads the record? Does 

 the record read itself? Memory is the power which 

 reads and identifies the record. 



If we try to explain memory by supposing it to be 

 the vibrations of molecules of nerve matter, we must 

 suppose that molecules which vibrate to-day recog- 

 nize the fact, by vibrating, that ten years ago entirely 

 different molecules vibrated in a similar way. This 

 theory of molecular motion is entirely inadequate to 

 explain any mental condition whatever. 



If we explain memory by saying, in general terms, 

 that it is the recurrence of a former condition of the 

 nervous system, this is insufficient, for the evident rea- 

 son that memory is more than this. 



To explain memory, therefore, it is necessary to 



