48 BULLETIN OF THE 



language which I have described. It is one of the most common 

 errors of discourse to assume that any common expression which 

 we may use always conveys an idea, no matter what the subject of 

 discourse. The true state of the case can, perhaps, best be seen by 

 beginning at the foundation of things, and examining under what 

 conditions language can really convey ideas. 



Suppose thrown among us a person of well-developed intellect, 

 but unacquainted with a single language or word that we use. It 

 is absolutely useless to talk to him, because nothing that we say 

 conveys any meaning to his mind. "We can supply him no dic- 

 tionary, because by hypothesis he knows no language to which we 

 have access. How shall we proceed to communicate our ideas to 

 him ? Clearly there is but one possible way, namely, through his 

 five senses. Outside of this means of bringing him in contact with 

 us we can have no communication with him. We, therefore, begin 

 by showing him sensible objects, and letting him understand that 

 certain words which we use correspond to those objects. After he 

 has thus acquired a small vocabulary, we make him understand 

 that other terms refer to relations between objects which he can per- 

 ceive by his senses. Next he learns, by induction, that there are 

 terms which apply not to special objects, but to whole classes of 

 objects. Continuing the same process, he learns that there are cer- 

 tain attributes of objects made known by the manner in which they 

 affect his senses, to which abstract terms are applied. Having 

 learned all this, we can teach him new words by combining words 

 without exhibiting objects already known. Using these words we 

 can proceed yet further, building up, as it were, a complete lan- 

 guage. But there is one limit at every step. Every term which 

 we make known to him must depend ultimately upon terms the 

 meaning of which he has learned from their connection with special 

 objects of sense. 



To communicate to him a knowledge of words expressive of 

 mental states it is necessary to assume that his own mind is subject 

 to these states as well as our own, and that we can in some way in- 

 dicate them by our acts. That the former hypothesis is sufficiently 

 well established can be made evident so long as a consistency of 

 different words and ideas is maintained. If no such consistency of 

 meaning on his part were evident, it might indicate that the opera- 

 tions of his mind were so different from ours that no such commu- 

 nication of ideas was possible. Uncertainty in this respect must 





