OF ARTS AND SCIENCES : NOVEMBER 13, 1867. 417 



the following considerations to show that this interpretation of history 

 is not exactly true. In the first place, it is said that a distinction was 

 taken between these attributes, as though they were previously con- 

 founded. Now there is not the least evidence of this. A German 

 logician, has, indeed, by a subtle misconception, considered extension as 

 a species of comprehension, but, to a mind beginning to reflect, no no- 

 tions seem more unlike. The mental achievement has been the bring- 

 ing of them into relation to one another, and the conception of them as 

 factors of the import of a term, and not the separation of them. In 

 the second place it is correctly said that the doctrine taught by the 

 Port Royalists is substantially contained in the work of a Greek com- 

 mentator. That work is no other than Porphyry's Isagoge * ; and there- 

 fore it would be most surprising if the doctrine had been totally over- 

 looked by the schoolmen, for whether their acuteness was as marvellous 

 as Hamilton taught or not, they certainly studied the commentary in 

 question as diligently as they did the Bible. It would seem, indeed, 

 that the tree of Porphyry involves the whole doctrine of exten- 

 sion and comprehension except the names. Nor were the scholastics 

 without names for these quantities. The partes subjectives and partes 

 essentiales are frequently opposed ; and several other synonymes are 

 mentioned by the Conimbricenses. It is admitted that Porphyry fully 

 enunciates the doctrine ; it must also be admitted that the passage in 

 question is fully dealt with and correctly explained by the mediaeval 

 commentators. The most, that can be said, therefore, is that the doc- 

 trine of extension and comprehension was not a prominent one in the 

 mediaeval logic, t 



* Porphyry appears to refer to the doctrine as an ancient one. 



t The author of " De Generibus et Speciebus " opposes the integral and diffinitive 

 wholes. John of Salisbury refers to the -distinction of comprehension and exten- 

 sion, as something " quod fere in omnium ore celebre est, aliud scilicet ess'e quod 

 appellativa significant, et aliud esse quod nominant. No'minantur singularia, sed 

 universalia significantur." (Metalogicus, lib. 2, cap. 20. Ed. of 1620, p. 111.) 



Vincentius Bellovacensis (Speculum Doctrinale, Lib. III. cap. xi.) has the fol- 

 lowing : " Si vero quaeritur utrum hoc universale ' homo ' sit in quolibet homine 

 secundum se totum an secundem partem, dicendum est quod secundum sc totuni, 



id est secundum quamlibet sui partem diffmitivam Non autem secundum 



quamlibet partem subjectivam." William of Auvergne (Prantl's Geschichte, Vol. 

 III. p. 77) speaks of "totalitatem istam, qua? est ex partibus rationis seu diffinitionis, 

 et hae partes sunt genus et differentia} ; alio modo partes speciei individua sunt, 

 quoniam ipsam speciem,cutn deeis prasdicatur,sibi invicem quodammodo partiunter." 



VOL. VII. 53 



