THE PREDICABLES. 81 



In his endeavour to establish a distinction between the character of the species 

 infima and that of its sub-classes, Father Clarke a apparently fails to distin 

 guish between the full (explicit) contents of the whole individual &quot;nature,&quot; and 

 the ever-diminishing (explicit) contents of the specific &quot;nature&quot; and the 

 generic &quot;nature&quot; as represented to us by each of the ascending series of 

 general class names and concepts in and through which we can think of that 

 individual. When he says of such attributes as &quot; white and coloured, &quot;virtuous 

 and vicious, heathen and Christian, Etiropean, Asiatic, American, African, 

 and Australasian&quot; in reference to &quot;man,&quot; that &quot; every one of them might 

 be conceived to be reversed without the man, so to speak, losing his identity,&quot; 

 he seems to forget that &quot; rationality &quot; and &quot;irrationality&quot; might be likewise 

 reversed without &quot;animal&quot; losing any part of what makes us think of it as 

 animal. So too, if a man &quot; is an European, he will not have his nature 

 changed if we suppose him born in Asia &quot; ; that is, his human nature : but 

 his Europeanism will be changed. &quot; If he is a negro we can think of him as 

 remaining in all respects the same, though his skin should be white.&quot; Not 

 quite ; he would remain a man, but would he remain a negro ? &quot; But if we 

 take any of the attributes which belong to man as such, it is quite different. 

 Take away from man the faculty of sensation and he is a different being at 

 once ... it [sensation] cannot be separated even in thought without destroy 

 ing his nature.&quot; Of course it cannot be taken away (no more than rationality ) 

 without destroying his human nature, for it forms a part of his human nature, 

 and if it be taken away &quot; he is a different being at once &quot; ; but its removal in 

 thought does not prevent his being still thought of as a living organism : just 

 as on the mental removal of &quot; European origin &quot; or &quot;dark-coloured skin &quot; the 

 individual would cease to be thought of as an European or a negro, though 

 he would still be thought of as a man. So far from being &quot;quite different,&quot; 

 the cases are quite similar as regards the relations of the attributes to the 

 logical classes in question ; nor is there any need to distinguish logically be 

 tween them. 2 



47. DIFFERENTIA AND PROPRIUM : CONNEXION OF PRO- 

 PRIUM WITH ESSENCE. Differentia : One concept is said to be 

 the differentia of another when it gives the attribute (or group) 

 which distinguishes the former from other co-ordinate species of 

 the same proxi mate genus. It is therefore the excess of connotation 

 in the concept of a species over that of its proximate genus. Seeing 

 that the same class of objects may find a place in different schemes 

 of classification, a different part of its connotation will stand as 

 differentia in each case. Thus if we compare &quot; man &quot; with other 

 &quot; animals &quot; his genus will be &quot; animal,&quot; his differentia will be 

 &quot; rational &quot; and his definition &quot; rational animal &quot; ; whereas, if 



1 CLARKE, Logic, pp. 182-4. 



2 See the same fallacious line of argument in Zigliara, Logica (5), vi., where the 

 author denies that dogs, horses, fishes, birds, etc. are true species &quot; quoniam in illis 

 speciebus peculiaribus differentia est accidentalis, non essentialis &quot; an observation 

 which applies equally to classes above the species infimae. Cf. JOSEPH, op. cit., p. 93. 



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