III.] PROI'OSITIONS 3n 



All definitions are necessarily of this form, whether the 

 objects defined be many, few, or singular. Tims we may bay, 



Coumion salt = Sodium chloride. 



Chloi'ophyl = Green colouring- matter of leaves. 



Square = Equal-sided rectangle. 

 It is an extraordinary fact that propositions of this 

 elementary form, all-inqiortant and very numerous as they 

 are, had no recognised place in Aristotle's system of Logic. 

 Accordingly their im])ortance was overlouked until very 

 recent times, and logic \vas the most deformed of sciences. 

 But it is impossible that Aristotle or any other person 

 should avoid constantly using them ; not a term could be 

 defined without their use. In one place at least Aristotle 

 actually notices a proposition of the kind. He observes : 

 " We sometimes say that that while thing is Socrates, or 

 that the object approaching is Callias."^ Here we certainly 

 have simple identity of terms ; but he considered such 

 propositions purely accidental, and came to the unfortunate 

 conclusion, that " Singulars cruinot be predicated of other 

 terms." 



Propositions may also express the identity of extensive 

 groups of olijects taken collectively or in one connected 

 whole ; as when we say. 



The Queen, Lords, and Commons = The Legislature of 

 the United Kingdom. 

 When Blackstone asserts that "The only true and natural 

 foundation of society are tlie wants and fears of individuals," 

 we must mterpict him as meaning that the whole of th" 

 wants and fears of individuals in the aggregate form the 

 foundation of society. Ijiit many propositions which 

 might seem to be collective are but groups of singular 

 propositions or identities. When we say " Potassium and 

 sodium are the metallic bases of ]>otash and soda," we 

 obviously mean, 



Potassium = Met.dlic base of potash ; 



Sodium = Metallic base of soda. 

 It is the work of grammatical analysis to separate the 

 various propositions often combined into a single sentence. 

 Logic cannot be propculy re(|uired to interpret the forms 

 and devices of ]an<;ua''e, ])ut ojilv to treat the meaning 

 when clearly exhibited. 



• Prior Amtlytics, i. c;q). xxvii. 3. 



