180 NAMES AND PROPOSITIONS. 



straight lines, and parallel, and the number of sides 

 four. The attribute, therefore, of having the oppo- 

 site sides equal, is a Proprium of the class paral- 

 lelogram ; and a Proprium of the first kind, which 

 follows from the connoted attributes by way of demon- 

 stration. The attribute of being capable of under- 

 standing language is a Proprium of the species man, 

 since, without being connoted by the word, it follows 

 from an attribute which the word does connote, viz., 

 from the attribute of rationality. But this is a Pro- 

 prium of the second kind, which follows by way of 

 causation. How it is that one property of a thing 

 follows, or can be inferred from another ; under what 

 conditions this is possible, and what is the exact 

 meaning of the phrase ; are among the questions 

 which will occupy us in the two succeeding Books. 

 At present it needs only be said, that whether a Pro- 

 prium follows by demonstration or by causation, it 

 follows necessarily; that is to say, it cannot but 

 follow, consistently with some law which we regard 

 as a part of the constitution either of our thinking 

 faculty or of the universe. 



8. Under the remainingpredicable, Accidens, are 

 included all attributes of a thing which are neither 

 involved in the signification of the name, ''whether 

 ordinarily or as a term of art) nor have, so far as we 

 know, any necessary connexion with attributes which 

 are so involved. They are commonly divided into 

 Separable and Inseparable Accidents. Inseparable 

 accidents are those which although we know of no 

 connexion between them and the attributes constitu- 

 tive of the species, and although, therefore, so far as 

 we are aware, they might be absent without making 

 the name inapplicable and the species a different 



