172 NAMES AND PROPOSITIONS. 



be traced : and finally, what are the common attributes, the 

 possession of which gives to them all, or to that portion of 

 them, the character of resemblance which has led to their being 

 classed together. When these common attributes have been 

 ascertained and specified, the name which belongs in common 

 to the resembling objects acquires a distinct instead of a vague 

 connotation ; and by possessing this distinct connotation, be- 

 comes susceptible of definition. 



In giving a distinct connotation to the general name, the 

 philosopher will endeavour to fix upon such attributes as, 

 while they are common to all the things usually denoted by 

 the name, are also of greatest importance in themselves ; either 

 directly, or from the number, the conspicuousness, or the 

 interesting character, of the consequences to which they lead. 

 He will select, as far as possible, such differentiae as lead to the 

 greatest number of interesting propria. For these, rather than 

 the more obscure and recondite qualities on which they often 

 depend, give that general character and aspect to a set of 

 objects, which determine the groups into which they naturally 

 fall. But to penetrate to the more hidden agreement on which 

 these obvious and superficial agreements depend, is often one 

 of the most difficult of scientific problems. As it is among the 

 most difficult, so it seldom fails to be among the most im- 

 portant. And since upon the result of this inquiry respecting 

 the causes of the properties of a class of things, there inci- 

 dentally depends the question what shall be the meaning of a 

 word ; some of the most profound and most valuable investi- 

 gations which philosophy presents to us, have been introduced 

 by, and have offered themselves under the guise of, inquiries 

 into the definition of a name. 



