IV NOMENCLATURE OF MENTAL OPERATIONS 117 



of "sweet," nevertheless is in full possession of 

 that complex idea, which, when he has learned 

 to employ language, will take the form of the 

 verbal proposition, " A sugar-plum will be sweet." 

 Thus, beliefs of expectation, or at any rate their 

 potentialities, are, as much as those of memory, 

 antecedent to speech, and are as incapable of 

 justification by any logical process. In fact, 

 expectations are but memories inverted. The 

 association which is the foundation of expectation 

 must exist as a memory before it can play its part. 

 As Hume says, 



". . . it is certain we here advance a very intelligible pro- 

 position at least, if not a true one, when we assert that after the 

 constant conjunction of two objects, heat and flame, for instance, 

 weight and solidity, we are determined by custom alone to ex- 

 pect the one from the appearance of the other. This hypothesis 

 seems even the only one which explains the difficulty why we 

 draw from a thousand instances, an inference which we are not 

 able to draw from one instance, that is in no respect different 

 from them." . . . 



" Custom, then, is the great guide of human life. It is that 

 principle alone which renders our experience useful to us, and 

 makes us expect, for the future, a similar train of events with 

 those which have appeared in the past." . . . 



"All belief of matter-of-fact or real existence is derived 

 merely from some object present to the memory or senses, and a 

 customary conjunction between that and some other object ; or 

 in other words, having found, in many instances, that any two 

 kinds of objects, flame and heat, snow and cold, have always 

 been conjoined together, if flame or snow be presented anew to 

 the senses, the mind is carried by custom to expect heat or cold, 

 and to believe that such a quality does exist and will discover 

 itself upon a nearer approach. This belief is the necessary result 



