313. A predicate is something which is stated of a subject.

314. A predicable is something which can be stated of a subject.

315. The Heads of Predicables are a classification of the various
things which can be stated of a subject, viewed in their relation to
it.

316. The treatment of this topic, therefore, as it involves the
relation of a predicate to a subject, manifestly falls under the
second part of logic, which deals with the proposition. It is
sometimes treated under the first part of logic, as though the heads
of predicables were a classification of universal notions, i.e. common
terms, in relation to one another, without reference to their place in
the proposition.

317. The heads of predicables are commonly reckoned
as five, namely,

(1) Genus.

(2) Species.

(3) Difference.

(4) Property.

(5) Accident.