ences stitutive, in another, divisive.taken in one way become constitutive, but in another divisive, they are all called specific.
8. Employment of specific differences: one definition of it. Cf. ch. 8; also Top. i. 8.These indeed are especially useful for divisions of genera, and for definitions, yet not with regard to those which are inseparable accidentally, nor still more with such as are separable.[1] And indeed defining these, they say that difference is that by which species exceeds genus, e. g. man exceeds animal in being rational and mortal, for animal is neither any one of these, (since whence would species have differences?) nor has it all the opposite differences, (since otherwise the same thing would at the same time have opposites,) but (as they allege) it contains all the differences which are under it in capacity, but not one of them in energy, and so neither is any thing produced from non-entities, nor will opposites at the same time subsist about the same thing.
9. Another definition. Cf. ch. 12 and 7; also Wallis's Log. lib. i. c. 4.Again, they define it (difference) also thus: difference is that which is predicated of many things differing in species in answer to the question, of what kind a thing is,[2] for rational and mortal being predicated of man, are spoken in reply to what kind of thing man is, and not as to the question what is he. For when we are asked what is man, we properly answer, an animal, but when men inquire what kind of animal, we say properly, that he is rational and mortal. For since things consist of matter and form, or have a constitution analogous to matter and form, as a statue is composed of brass, matter, but of figure, form, so also man, both common and specific, consists matter analogous to genus, and of form analogous to difference,[3] but the whole of this, animal, rational, mortal, is
- ↑ Boethius agrees with Porphyry, that accidents, properly so called, are useless in definition, (vide Opera, p. 3,) accidental definition is, in fact, merely a description. Cf. Albert. l. c. Occam, pt. i. ch. 27. The only proper definition is by genus and differentiæ, hence all definable notions will be species. The definition here given of difference, as to its being the excess of species over genus, is clear, from a reference to what was stated in the last note of the preceding chapter.
- ↑ "Ratione ejus, quale quid est predicatur." Buhle; so Aldrich. There is no warranty, as we have observed, by Porphyry, for distinction between "quale quid" and "quale."
- ↑ Taylor reverses this:—the reader will find what follows profitably illustrated by Whately, in his supplement to ch. 1, Logic, and Mansel's Appen. A and B.
