16. Logical Categories or Predicaments. -- Obviously, it is out of the question to go in detail through all the predicates of the judgments which the human mind enunciates under an indefinite variety of forms. But Aristotle has essayed to reduce them to certain types of attribution, so as to understand what determinations they bring to the subject which experience supplies, each type of attribution (typus praedicationis) constituting a category of homogeneous concepts. He recognized the existence of ten great kinds of predicates or attributes, the sum of which is virtually equivalent to all the range of human thought, and in one or other of which it is possible to find a place for any concept whatsoever.

What are the ten predicaments or categories? (1) Substance, that is, second or abstract, substance.

This thing which we perceive as white, cold, light, is some snow. Some snow represents, under an abstract form the substance to which our senses find attached those accidental determinations which are expressed by the adjectives white, cold, light. When the mind attributes an abstract substance to the concrete substance, tode ti, perceived by the senses, it applies to that concrete substance the first category, he ousia, ti esti.

In contradistinction to the individual subject, prôtê ousia, prima substantia, upon which all predicates rest (15), the category of substance is called deutera ousia secunda substantia. The latter, indeed, can be the subject of attributes, but it presupposes a concrete subject to which it is referred.

(2) The other nine types of attribution represent accidental determinations.^{1}

Of these some are inherent in the subject to which the mind attributes them; two of them are absolutely inherent in the subject considered, the categories of quantity (e. g., two feet long) and of quality (e. g., white, learned); a third belongs to the subject in respect to a being or beings other than itself -- the predicament of relation (e. g., double).

Certain predicates represent something extrinsic to the subject; the predicates of place (e. g., in the public street), of time (e. g., yesterday) are borrowed from measure, the one of quantity, the other of the duration of the subject.

Action and passion are attributable to the subject because it is the principle (origin) of the former and the term, or aim, of the latter (e. g., he cuts the stone; the stone is cut).

The last two categories, the meaning of which has much exercised Aristotle's commentators, seem to have been felicitously interpreted by the philologist, Max Müller, who sees in the word keisthai, intransitive action, the active intransitive verb (e. g., I walk, I am afraid), in echein, the passive intransitive state (e. g., I am feeling well).^{2}

{1} On the difference between the substantial quiddity which we take hold of by our logical predicates, see General Metaphysics, nos. 83 sq.

{2} St. Thomas, In Met., V, lect. 9.