474 



Mr DE morgan, ON THE SYLLOGISM, No. V. AND 



Hamilton, that Leibnitz, a mathematician, is not Newton, we deny "mathematician" of 

 Newton; not "any" mathematician, but the mathematician incorporated in Leibnitz; Newton 

 is not the LmaEthelmaBNtilciTanZ who is here spoken of. He means that each quality 

 residing, inhering, in a subject is an object of thought, per se, as a quality, distinct from, 

 though a component of, the subject of inhesion, and from the same quality in any other sub- 

 ject. All this can be thought : what is its force as a distinct mode of enunciation ? and what 

 is its utility in logic ? Show me the first, and I can undertake to find the second. 



Two objects are in a certain particular alike, so that if they were as much alike in all 

 particulars they would be the same object. If Leibnitz, besides mathematician, had been 

 English, Fellow of Trinity, Lucasian professor, &;c. &c. &c. he would have been Newton : and 

 the proper name Leibnitz would have been but an alias of Newton. What ! it will be asked, 

 do you deny that in thought you can conceive two men, facsimiles in body and mind, 

 thinking, speaking, and acting, exactly in the same way, Sec &c. &c., all through their lives .'' 

 If the querist mean that they are to differ in place or in time, I can conceive two different 

 men, each the double of the other in all things except place or time. But if, among the other 

 samenesses, they be to occupy the same place at the same time, I cannot call them two men. 

 If I could, I should say there is no such thing as an individual ; that each one man is a 

 hundred, or a thousand, agreeing in all things, place included, at all times, and therefore 

 without distinction. Suppose one individual to differ from another only in one quality, the 

 first being AXYZ...and the second BXYZ..., A and B being repugnant. Hamilton says 

 they have two different X qualities, Xj and Xj! let it be so; the individuals are then 

 AX,Y,Z,... and AXjYaZj... If A and B had chanced to be the same, these two individuals 

 would have been wholly without distinction — would have been the same. Remember that 

 we are supposed to have enumerated every concept under which either is viewed or which 

 either receives or creates. If then, which I do not deny, X, and Xg be really different 

 examples of the same quality, all knowledge of this difference — the very difference itself, as to 

 the esse quod habet in anima — is due to the difference of A and B. What then is the 

 logical import of a method by which, because there are differences which distinguish, we read 

 samenesses into different samenesses, and contend that agreements, as such, have differences of 

 which only disagreements wholly independent of the agreements make us cognizant. 



Again, why do we give a class-mark, a term-name .■' to distinguish the objects of the 

 class from all others, and (pro tanto) to confound them with one another. As against all 

 other species, each is signatum by the class-mark ; thus, though there be many men, 

 I distinguish Newton and Leibnitz by the attribute humanity from each and every brute. 

 But as against each other, this common class-mark is vagum: though I know each to be 

 man, I do not know them to be different men till I have found another class-mark, the 

 property of one, but not of the other. When the Irishman had caught the cluricaune, 

 and made him show under which thistle out of many acres of them the treasure was buried, 

 he tied his garter round the thistle — he added one' additional class-mark — and ran home for 



' The logician must not say that he merely distinguished 

 an individual, and did not include in a class: independently of 

 the truth, sometimes denied, that a class may consist of one 



individual only, his own remaining leg, and many other legs, 

 were fellow-members with the designated thistle. 



