15. Logical Problems Arising Out of the Act of Mere Apprehension. -- The concept can have nothing to do with logic except either as subject or as predicate.

I. In the last analysis, but only in the last analysis, the subject of the proposition is always individual. To be sure the proposition can have as its subject -- indeed often has -- an abstract type, but in such a case this is the predicate of an antecedent subject. The reason of this is twofold:

(a) Psychological: The first object of thought is taken from sensible experience, which is incapable of seizing anything but an individual and concrete reality.

(b) Ontological: Only the individual is, rigorously, a subject. Aristotle calls it pro^te^ ousia first substance. For, on the one hand, it is not attributable to any antecedent subject. Individuality is in fact incommunicable to something else: Socrates is Socrates, he is identified only with himself.^{1} On the other hand this first substance is the subject of abstract and universal concepts which can be attributed to it on various grounds.^{2}

Take the proposition: Snow melts in the sun. Snow is an abstract subject. -- But what is snow? Something white which I see falling in light flakes, and which I feel to be cold to the touch. This thing that is white to the sight, cold to the hands, and falls in light flakes, is some snow. This something which our senses perceive as white, cold, light, is a first subject; of this first subject, some snow is predicated. Snow then becomes the subject of a further predicate, the property of melting in the sun.

An examination of the terms of a proposition brings us face to face with a first term which is by its origin an individual subject (tode ti) and to which our thought refers all its predicates.

The individual subject being disposed of, there remains the predicate.

II. The predicate is the object of two principal considerations.

(1) What does it represent, what does it say about the subject? -- The study of the logical categories, or predicaments.

(2) How is it connected with the subject? in what manner must it be attributed to the subject? -- The study of categoremes or predicables.

{1} Cf. General Metaphysics, no. 46.

{2} "Of all things that are, some are such that they cannot be truly predicated of any other, as Cleon and Callias, both a singular thing and something that is subjected only to the senses, but other things can be predicated of them; for either of these [sc. Cleon and Callias] is a man and an animate being." Aristotle, Prior Anal., I, 27.