70 



HABIT AND INTELLIGENCE. 



[chap. 



Hearing 



■words 



and 

 sentences, 



memory is necessary, in order that a number of impressions 

 successively received by sensation should combine to make 

 Necessity a single total impression on consciousness. The sound of 

 thought ° ^ word, for instance, if it is a word of more than one letter, 

 consists of a number of different sounds reachino- the ear 

 successively ; and in order that the successive impressions 

 on the sensation may make one practically simultaneous 

 impression on the consciousness, it is obvious that while 

 the mind is receiving any one of the successive impressions, 

 it must not have lost the consciousness of those already 

 received. The same is true of the words of any short 

 iatelligible sentence ; though the words are heard succes- 

 sively, the total meaning of the sentence is practically 

 flashed on the consciousness at once. The effect of this 

 power is much more than merely to economize time in 

 thinking ; if we did not thus retain the consciousness of a 

 Sensation after the sensation itself has given place to 

 another, it would be impossible to cognise the relation 

 between two successive impressions, and thought — at least 

 all thought which, like ours, is developed under the con- 

 ditions of time, — thought, I say, would be, not slow, but 

 impossible. 



This power of retaining impressions in the consciousness 

 for some short time is, however, only the rudimentary form 

 Memory is of memory. The developed form of memory consists not 

 byThe^Taw ^^ retaining impressions in the consciousness, but in the 

 of associa- liability of the impressions to be recalled into consciousness. 

 This takes place under the law of mental habit, or the 

 association of ideas : an impression on the consciousness 

 recalls to memory another impression which has become 

 habitually associated with the first ; as, for instance, when 

 the sound of a friend's voice recalls the imas;e of his face. 

 This, of course, is true not only of feelings of sensation, but 

 equally so of those classes of impressions on consciousness 

 which have their source within the mind itself. In other 

 words, the law of memory by association is equally true 

 of sensations, of emotions, and of thoughts. By the esta- 

 blishment of such associations, it becomes possible for one 

 sensation or thought to produce not only the consciousness 



