SUBJECT. — The term s. has various meanings. In current usage one speaks of the s. of a proposition, a discussion, a work, or a science, meaning that of which they treat; it derives in fact from the Latin subiectum: that which lies beneath, which is subjected (to reflection, discussion, etc.).
The Latin term translates the Greek ὀποκείμενον, which already in Aristotle assumes a complex reference, possessing simultaneously a logical and a metaphysical value; logically, it is that of which a predicate is affirmed or denied, while metaphysically it is both indeterminate matter and the determinate being that sustains qualities and affections (cf. Phys., I, 2, 185 a 32; Met., VII, 3, 1029 a 1). This latter meaning, together with the logical one, passed directly into the tradition as the specific meaning of s. Aristotle himself (Cat., 2) clarifies and distinguishes these two uses of the term, demonstrating that the logical s. of a proposition does not always coincide with the real s., or the subject of inherence; for it is one thing to affirm or deny an attribute of an s., as in the case in which the genus is predicated of the species or the species of the individual (in Socrates is a man, man in general is attributed to Socrates, but it is not in Socrates), and another to refer to the s. a quality which, even without being its essential attribute, is in the s. itself (e.g., Socrates is wise). The distinction between the logical s. and the grammatical s. must also be noted; the latter is determined solely by the form of the proposition and does not always coincide with the former.
The fundamental meaning of s. in post-Aristotelian philosophy, down to the modern age, is that deriving from its value as substantial being, in opposition to the attributes or accidents referred to II. substance (v.), essence (v.), hypothesis, etc. In scholastic terminology esse subiective means to exist in oneself, esse obiective to subsist only in thought. Descartes too still defines as “subjective” that which belongs properly to things, formaliter in se iptis, and as “objective” that which is precisely the object of thought, which exists idealiter in intellectu (cf. Medit., III).
Only from the seventeenth century onward does that meaning of s. become increasingly prominent which derives from its being also the s. of activity, besides being the s. of qualities, and in particular of cognitive activity. Initially consciousness itself was considered one of the qualities of an s.; then, with the new formulations of the gnoseological problem, it increasingly assumed the value of an activity proper and essential to the s., until it came to coincide with the s. itself. Conversely, the term “object” (v.) came to signify reality in itself, independent of thought. This reversal of meanings was definitively sanctioned by Kantian philosophy (Kritch d. r. Vernungi passim) and by idealism. S. and object undergo the same fluctuations of meaning and the same distinctions (e.g., transcendental s., empirical s., etc.).
The primitive meaning of s., which has remained in common usage, is often confused with the now-established meaning of “object”; a distinction is nevertheless possible: s. is generally that which is actually under discussion, while “object,” more precisely, is that which a discussion, a scientific investigation, etc., set out to attain.