Isagoge: Chapter 2:4 — Of the Nature of Genus and Species

So, how many genera and species are there? First, there are the ones in the middle:

Now, the media of the extremes they call subaltern species and genera, and admit each of them to be species and genus, when referred indeed to different things, for those which are prior to the most specific, ascending up to the most generic, are called subaltern genera and species. Thus, Agamemnon is Atrides, Pelopides, Tantalides, and lastly, (the son) of Jupiter,….

OK; we talked about this kind yesterday. Why go on about it now?

…yet in genealogies they refer generally to one origin, for instance, to Jupiter; but this is not the case in genera and species, since being is not the common genus of all things, nor, as Aristotle says, are all things of the same genus with respect to one summum genus.

Aha! In a genealogy (aha! genus; genealogy. D’oh!) there’s one genus that’s most generic. But there is no single genus to which all beings belong. Why? Because “being” is a term of courtesy:

Still, let the first ten genera be arranged, as in the Categories, as ten first principles, and even if a person should call all things beings, yet he will call them, so he says, equivocally, but not synonymously, for if being were the one common genus of all things, all things would be synonymously styled beings, but the first principles being ten, the community is in name only, yet not in the definition also belonging to the name: there are then ten most generic genera.

Substances are different than quantities, which are different than qualities, which are different than relations, etc. We call all of these things “beings” by courtesy, in that they can all be objects of thought, but clearly “whiteness” is a different class of thing than “dog”. Per Aristotle, there are ten distinct kinds of thing, the ten Categories, and hence ten most generic genera. There are ten trees, with the Categories as starting points.

On the other hand, the most specific they place in a certain number, yet not in an infinite one, but individuals which are after the most specific are infinite; wherefore, when we have come down to the most specific from the most generic, Plato exhorts us to rest, but to descend through those things which are in the middle, dividing by specific differences; he tells us however to leave infinites alone, as there cannot be science of these.

OK, there are a finite number of most-specific species, what we might call species proper; why, necessarily, a finite number? But individuals within species are infinite. Again, why? And per Plato, we should think about the genera and species and not waste any time on individuals, because there cannot be any certain knowledge of these….because, evidently, the number of them is infinite. Of course, we know that Plato regarded the Ideas (which would correspond, presumably, to the genera and species) as really real, and the things we perceive with our senses as less so, and I presume this dictum has something to do with that. Aristotle and Thomas disagree.

In descending then, to the most specific, it is necessary to proceed by division through multitude, but in ascending to the most generic, we must collect multitude into one, for species is collective of the many into one nature, and genus yet more so;….

Oh, right, that’s where division comes from. When I take a concept and make a distinction, I’m logically dividing the concept. Anyway, yes, genera have greater extension than the species within them.

….but particulars and singulars, on the contrary, always divide the one into multitude, for by the participation of species, many men become one man; but in particulars and singulars, the one, and what is common, becomes many; for the singular is always divisive, but what is common is collective and reductive to one.

Again, I see the Platonic hand here. Particulars, like “Some men have black hair,” clearly divide the one essence, human nature, into a multitude of individual men. But in what sense can we possibly say that a singular, like Socrates, we divide human nature into a multitude?

Comments are closed.