Phi201 - Porphyry and Boethius

Last time - species and genus

What distinguishes species-terms and genus-terms like "cat", "animal", "material being", "substance", from others is that at least partly,

(A) they are predicated essentially, as opposed to accidental quality-terms like "white"

(B) they describe the objects they predicated of in terms of what they are, as opposed to how they are. This distinguishes them from essential quality terms like rational" <-- as applied to human beings.

Roughly speaking, an essential quality-term is a difference-term

Differences <--- 3rd of Porphyry's 5 predicables

See quote 4 - wk 6 Handout

There are 3 senses of "difference" that Porphyry mentions.

-Difference in terms of accidental quality that is seperable, i.e easily lost.

-Difference in terms of accidental quality that is insemmible, i.e not easily lost.

-difference in terms of essential quality.

The former two makes things that differ in accordance with them merely 'otherwise', as I am otherwise from myself as a child in virtue of no longer having a full head of hair. The last makes thing that differ in accordance with it not just otherwise but 'other', as I am different from a horse in capacity for rationality which is a specific difference, I am other then it.

Being quality-terms rather then substance-terms all 3 sorts of difference-terms in themselves describe how rather than what. But specific-difference terms relate to what in a derivative way, i.e, in that adding a specific difference term like
"rational" to a substance-temr like "animal" can define a species-term like "human".


Property - Four senses of "property" are distinguished, all narrower than modern sense, because all Porphyry's senses require a 'property' to be accidental. (We moderns can speak of 'essential properties' but for Porphyry (i.e in Porphyry's senses of the term) that would be a contradiction in terms)

For Porphyry, the sense he's really interested in is the strictest sense, the fourth. In that sense a property is an accidental quality that applies to all and only members of one species, and to each member throughout its existence. So risibiility, the capacity for laughter, is in this strictest sense a 'property' of humans. Doing medicine fails the first require (all), being bipedal fails the second (only) and being grey-haired fails the last (at every time)

Accident = self-explanatory.