CONSCIOUS AND UNCONSCIOUS MEMORY 399 



imported diseases. The average individual amongst us, and 

 doubtless amongst the Maoris, may be trained to fill the role of a 

 beggar or a king, a scientist or a monk, a thief or legislator. He 

 is so intelligent, so adaptable that he is able to dwell in the tropics 

 or in the Arctic, in the city or the wild, on land or on sea. Memory, 

 knowledge, intelligence, reason, adaptability, are all links in a 

 single chain of efficiency. 



660. Memory is of two sorts, conscious and unconscious. The 

 conscious memory contains experiences which can be ^-collected, 

 such as scenes we have beheld, or the words of a language. The 

 unconscious memory contains impressions which cannot be recalled 

 to mind, but which are none the less important. Indeed, many of 

 its contents were never present in consciousness in the sense that 

 a sight, an emotion, or an idea is present. Thus we learn to use 

 our legs in walking, a process that involves a precise but unconscious 

 adjustment of the actions of numerous muscles, the very existences 

 of which are unknown except to the anatomist. In a sense, therefore, 

 we know as little about walking as any insect. All our acquired 

 dexterities, both in thinking and acting, belong to this category. 

 They are mental acquirements stored by the unconscious memory. 

 Thus we learn to reason ; but, though we recall some of the times 

 and lessons by which we learned to think well, and though results 

 may make us conscious of a growing facility in reasoning, yet the 

 facility itself, like dexterity in walking, is a thing that is outside 

 our consciousness. So also, to some extent at least and especially 

 in youth, we unconsciously imitate our fellows, adopting in great 

 measure their mental tones and attitudes without knowing how or 

 when we were influenced. Many experiences, too, once capable of 

 being distinctly recalled, are added to that hidden store, and, 

 though apparently lost, remain potent for good or evil. Our minds 

 are like floating icebergs, of which the visible part is but a fraction 

 of the whole, and which are moved by deep currents in a seemingly 

 unaccountable way. 1 



1 I speak of the ' unconscious memory.' The expression is in common use, and 

 is convenient. But, properly speaking, memory is the faculty for storing and 

 recalling to consciousness feelings that have been there before. An unconscious 

 memory, therefore, is a contradiction in terms. Probably what we call uncon- 

 scious memory is nothing other than a growth in efficiency, or in size, or in com- 

 plexity, or in all three, of brain ; a growth which enables that organ to perform 

 work which till then it was incapable of performing, or which it was incapable of 

 performing as easily or as well. In physiological and psychological writings this 

 cerebral change is usually spoken of as an " opening up of paths " in the brain. 

 If by that is meant a building-up in the brain analogous to that building which 

 occurs when an addition is made to our means of telephonic communication, the 



