196 NAMES AND PROPOSITIONS. 



no definition can unfold its whole nature ; and every 

 proposition in which any quality whatever is predi- 

 cated of the thing, unfolds some part of its nature. 

 The true state of the case we take to be this. All 

 definitions are of names, and of names only: but, in 

 some definitions, it is clearly apparent, that nothing is 

 intended except to explain the meaning of the word ; 

 while in others, besides explaining the meaning of the 

 word, it is intended to be implied that there exists a 

 thing, corresponding to the word. Whether this be 

 or be not implied in any given case, cannot be col- 

 lected from the mere form of the expression. C A cen- 

 taur is an animal with the upper parts of a man and 

 the lower parts of a horse/ and ' A triangle is a 

 rectilineal figure with three sides,' are, in form, expres- 

 sions precisely similar ; although in the former it is 

 not implied that any thing, conformable to the term, 

 really exists, while in the latter it is ; as may be seen 

 by substituting, in both definitions, the word means 

 for is. In the first expression, ' A centaur means an 

 animal/ &c., the sense would remain unchanged: in 

 the second, 'A triangle means/ &c., the meaning 

 would be altered, since it would be obviously impos- 

 sible to deduce any of the truths of geometry from a 

 proposition expressive only of the manner in which 

 we intend to employ a particular sign. 



" There are, therefore, expressions, commonly pass- 

 ing for definitions, which include in themselves more 

 than the mere explanation of the meaning of a term. 

 But it is not correct to call an expression of this sort 

 a peculiar kind of definition. Its difference from the 

 other kind consists in this, that it is not a definition, 

 but a definition and something more. The definition 

 above given of a triangle, obviously comprises not 

 one, but two propositions, perfectly distinguishable. 



