404 THE EVOLUTION OF MEMORY 



formal endeavour to develop the faculty by means of special 

 exercises. 



667. The range of thought possessed by any species is always 

 proportionate to the greatness of the conscious memory, which 

 records not only items presented by the senses, but also those 

 acquired through the imagination and intelligence. On this 

 account the dog has a greater range than the cat, and man than 

 the dog. Man's unique intellectual powers depend wholly on his 

 vast and capacious memory by means of which he acquires both 

 the materials (facts and ideas) and the methods (association, dis- 

 crimination, and the like) of thought materials and methods 

 which render him intelligent, rational, 'self-conscious,' capable 

 of 'conceptual thought' and of 'apprehending universals,' and 

 abstract ideas such as those of right and wrong, and of performing 

 feats of thinking as in mathematics, philosophy, and science, or of 

 imagination as in music, poetry, and fiction, or of ingenuity as in 

 engineering and warfare, or of becoming devout or patriotic, and 

 so forth. The fact that he alone, of all animals, is capable of these 

 mental operations has caused many writers to declare that an 

 impassable gulf separates him from the rest of living nature. But 

 plainly there is no impassable gulf. None of the traits mentioned 

 are 'inborn' or special products of evolution or creation. The 

 infant possesses none and can possess none until his memory is 

 stored with the materials of thought and he has learned through 

 imitation and practice fit methods of thinking. He differs from 

 lower animals only in that his memory is so large that it alone is 

 capable of being stored with these traits amongst many others. 

 That which has been created by evolution is his huge cerebrum, 

 the organ of memory, the thing which does the work which is 

 memory, reason, and all the rest which results from acquirement. 

 Both cerebrum and memory are found in lower animals, and there 

 is no greater difficulty in conceiving man's mental evolution 

 through the continued selection of mentally superior individuals 

 (that is, of individuals who are mentally superior because they have 

 a superior quality of brain) than of conceiving the evolution of the 

 elephant's trunk, the bat's wing, or any other structure that 

 especially distinguishes this or that animal. 



668. Not only may memory vary as a whole, but it may vary 

 in particular directions in different individuals. Thus, while one 

 man may possess exceptional powers of acquiring the facts and 

 methods of mathematics and of learning to use his knowledge for 

 purposes of fresh discovery, another man may be similarly dis- 



