PROPOSITIONS. 87 



guage corresponds, on different occasions, to different words 

 in another. When not thus exercised, even the strongest 

 understandings find it difficult to believe that things which 

 have a common name, have not in some respect or other a 

 common nature ; and often expend much labour very unpro- 

 fitably (as was frequently done by the two philosophers just 

 mentioned) in vain attempts to discover in what this common 

 nature consists. But, the habit once formed, intellects much 

 inferior are capable of detecting even ambiguities which are 

 common to many languages : and it is surprising that the one 

 now under consideration, though it exists in the modern lan- 

 guages as well as in the ancient, should have been overlooked 

 by almost all authors. The quantity of futile speculation 

 which had been caused by a misapprehension of the nature 

 of the copula, was hinted at by Hobbes; but Mr. James Mill* 

 was, I believe, the first who distinctly characterized the ambi- 

 guity, and pointed out how many errors in the received systems 

 of philosophy it has had to answer for. Tt has indeed misled 

 the moderns scarcely less than the ancients, though their 

 mistakes, because our understandings are not yet so com- 

 pletely emancipated from their influence, do not appear equally 

 irrational. 



We shall now briefly review the principal distinctions 

 which exist among propositions, and the technical terms most 

 commonly in use to express those distinctions. 



2. A proposition being a portion of discourse in which 

 something is affirmed or denied of something, the first divi- 

 sion of propositions is into affirmative and negative. An 

 affirmative proposition is that in which the predicate is 

 affirmed of the subject ; as, CaBsar is dead. A negative pro- 

 position is that in which the predicate is denied of the subject ; 

 as, Caesar is not dead. The copula, in this last species of 

 proposition, consists of the words is not, which are the sign of 

 negation ; is being the sign of affirmation. 



Some logicians, among whom may be mentioned Hobbes, 



* Analysis of the Human Mind, i. 126 et seq. 



