VERBAL AND REAL, PROPOSITIONS. 127 



Nothing has probably contributed more to the opinion 

 so long prevalent of the futility of the school logic, than the 

 circumstance that almost all the examples used in the common 

 school books to illustrate the doctrine of predication and that 

 of the syllogism, consist of essential propositions. They were 

 usually taken either from the branches or from the main trunk 

 of the Predicamental Tree, which included nothing but what 

 was of the essence of the species : Omne corpus est substantia, 

 Omne animal est corpus, Omnis homo est corpus, Omnis homo 

 est animal, Omnis homo est rationalis, and so forth. It is 

 far from wonderful that the syllogistic art should have been 

 thought to be of no use in assisting correct reasoning, when 

 almost the only propositions which, in the hands of its pro- 

 fessed teachers, it was employed to prove, were such as every 

 one assented to without proof the moment he comprehended 

 the meaning of the words ; and stood exactly on a level, in 

 point of evidence, with the premises from which they were 

 drawn. I have, therefore, throughout this work, avoided the 

 employment of essential propositions as examples, except 

 where the nature of the principle to be illustrated specifically 

 required them. 



5. With respect to propositions which do convey in- 

 formation which assert something of a Thing, under a 

 name that does not already presuppose what is about to be 

 asserted ; there are two different aspects in which these, or 

 rather such of them as are general propositions, may be con- 

 sidered : we may either look at them as portions of speculative 

 truth, or as memoranda for practical use. According as we 

 consider propositions in one or the other of these lights, their 

 import may be conveniently expressed in one or in the other 

 of two formulas. 



According to the formula which we have hitherto employed, 

 and which is best adapted to express the import of the pro- 

 position as a portion of our theoretical knowledge, All men 

 are mortal, means that the attributes of man are always 

 accompanied by the attribute mortality: No men are gods, 

 means that the attributes of man are never accompanied by 



