CORRESPONDENCE, 1856-66. 307 



as I am able to judge, relation goes into everything ; no quality 1861, 

 existing except as related to some other, which we sometimes 

 call its negative, at other times its contrast, and again its cor- 

 relative. The straight line has no meaning without its contrast, 

 the bent line ; the occurrence of the two kinds is necessary to 

 our recognising either property. Every quality, every cognition 

 of the mind, implies an antithesis or couple. Hot cold, up 

 down, &c. If I say red, I mean to exclude all other members of 

 my ' universe ' (to use your own well-chosen designation) ; and 

 if that be'* colour,' I exclude all other colours. The important 

 inferences deducible from the essential doubleness of all cognition 

 are, I am sure, very numerous, and I have no doubt you will con- 

 vince us of this if you continue the subject. 



Yours faithfully, 



ALEX. BAIN. 



To Professor Alexander Bain. 



41 Chalcot Villas, Adelaide Road, N.W., 



Feb. 9, 1861. 



MY DEAR SIR, I am sorry to have given you the trouble of 

 returning my second copy. I see I must have entered you as 

 of two Universities. 



I quite coincide in your view as to a quality being unthink- 

 able except in company with its non. I forget where I said, long 

 ago, every name designates every object of thought as either in 

 the class or out ; but I did say it, and the equipollence of X and 

 non-X is the foundation of completeness even in common syllogism. 

 I hardly like to claim the word universe as mine, though I have 

 brought it down from its modern sense (the TO irav) to the old 

 sense. Those who have derived the word from a mixture of 

 unum and diver sum (strange etymologists !) certainly very much 

 favour my plan of making it any aggregate of X and non- 

 X which is in hand. But the old universal was any name which 

 had plurality of things signified : of two only, the name turned 

 the two into one, in unum versa. I have made some people stare 

 by telling them that universality begins at two. 



The combinations of relation are the ambiguities of language. 

 Looking on a little into compound relation, I come to such a 

 sentence as the following : 



* He is the father of a friend of every one of my children.' 



Do I mean that one of his children is the friend of every one 



x 2 



