Substance

SUBSTANCE. - It can indicate both actual and concrete, that is, singular reality (the "primary substance" of Aristotelian terminology), and essence (v.), whether in its metaphysical structure or in its notional and logical content ("secondary substance": cf. Cat., 5, 2 a 11 ff.), or even the particular "this" (τόδε τι) and the "what it is" (τὸ τί ἔστιν: Met., VIII, 1, 1028 a 11).

By substance, therefore, is meant the "principal" mode of being, and hence the first category of the real, the foundation, cause and substratum of accidents (v.), both proper and common. Consequently the meaning of "subject" or "substratum" (τὸ ὑποκείμενο) varies according to the number of modes of substance itself in the logical or real order, namely: 1) insofar as substance is the principal reality that sustains accidents, and is then spoken of in the strict sense as τὸ εἶδος or ἡ μορφή (Met., VIII, 3, 1028 b 34); 2) the same ultimate subject or prime matter (πρώτη ὕλη); 3) in the logical order, the universal (τὸ καθόλου), which is the species and the genus. Insofar, moreover, as it indicates the consistency of being, 4) substance is reality in act (οὐσία), which can be indicated as the essence complete in itself (a synthesis, in the corporeal being, of matter and form, τὸ σύνολον: Met., VIII, 3, 1033 b 1), or finally 5) the singular subsisting thing (τόδε τι), which is substance in the full sense, in which the real is actualized in its various forms.

In the anti-Platonic polemic (Met., I and VII-VIII) Aristotle maintained that substance is to be indicated in sensible reality, with which experience puts us in continuous contact and on which we necessarily always depend both for knowing and for acting. The Platonic problem, therefore, of the "communion of genera" (κοινωνία τῶν γενῶν), which in Plato always remained oscillating, becomes in Aristotelianism the problem of the "duality" of matter and form in the essence, and of genus and difference in the definition (v.). But the duality of the principles does not destroy — indeed it guarantees — the unity of the real on the one hand and of the concept on the other. Such unity is in fact guaranteed, in the real, by the unity of the form, and in the definition by the specific difference, which is constitutive of the essence and corresponds to the form. In this way, in Aristotelianism the process to infinity is closed (which instead remains open in Platonic dialectic), because the form is immanent in the sensible singular, so that matter informed and form actuating matter coincide in the unity of the being: ἡ ἐσχάτη ὕλη καὶ ἡ μορφὴ ταὐτὸ καὶ ἕν, καὶ δυνάμει, τὸ δ'ἐνεργείᾳ (Met., VIII, 5, 1045 b 18). Matter and form, therefore, in the structure of substance (and of the definition) are not found on an equal footing, but the form dominates matter and actuates it in its ontological grade: "Unumquodque ponitur in sua specie per formam..." (St. Thomas, In VII Met., lect. 11, n. 1531: cf. Sum. Theol., 1ᵃ, q. 85, a. 1 ad 2). In the metaphysical structure of the corporeal essence, therefore, form and matter (and soul and body) are like the concave and the convex, and not two elements that require an "intermediate principle" of connection. This latter conception betrays a dualism that conceives the two principles separately and, ultimately, a failure to understand the metaphysics of act and potency: "Ultima materia, quae scilicet est appropriata ad formam, et ipsa forma, sunt idem. Aliud enim eorum est sicut potentia, aliud sicut actus... Et sic non oportet ea uniri per aliquod vinculum" (In VIII Met., lect. 5, n. 1767). The theory of the "substantial bond" was developed by Leibniz and his school, but the first explicit traces appear in Suárez, from whom in all probability Leibniz himself took the inspiration (as Ch. Boehm has demonstrated [Le vinculum substantiel chez Leibniz, Paris 1938], who corrects on this point the thesis of M. Blondel [Une énigme historique: Le « vinculum substantiale » d'après Leibniz et l'ébauche d'un réalisme supérieur, ibid. 1930: it is the French translation of the Latin thesis of 1893]). For his part Leibniz (v.) elaborated a theory of substance as a "monad" complete in itself, so that every substance, even material, is a world apart; what St. Thomas says of the angels, that each is a species apart, according to Leibniz "est de toutes les substances... De plus, toute substance est comme un monde entier et comme un miroir de Dieu ou bien de tout l'univers, qu'elle exprime chacune à sa façon" (Discours de métaphysique, § IX; ed. H. Lestienne, Paris 1929, p. 37). More sober in its theoretical exigency, Thomist metaphysics elaborated the concept of substance according to the principle of the "emergence of act" (Met., IX, 8, 1049 b 5; cf. De an., II, 4, 415 a 18). Material substance obtains its actuality and ontological consistency from form: (Quod., I, q. IV, a. 6; cf. Arist., De an., II, 4, 415 b 13: τὸ γὰρ αἴτιον τοῦ εἶναι πᾶσι ἡ οὐσία). Consequently, spiritual substances, which are simple forms without matter, are more perfect and more consistent than material substances, and for this reason are called "subsisting" or separate forms, and as such are closer to God, who is pure subsisting being (cf. De spir. creat., a. 1). Then in the ontological structure of substance, as "subsistence" (v.) increases, the reason of subject or receptivity with respect to accidents diminishes; these in spiritual substances are reduced to the sole qualities and actuations of the intellect and the will, while God is pure act, fullness of perfection in absolute simplicity.

The rupture of the equilibrium of Aristotelian metaphysics of act and potency, already accomplished in Suárez, who does not accept the Thomist concept of potency, shows in Leibniz the elimination of potency as receptivity in order to intensify potency as virtuality and activity. In Spinoza (v.), by contrast, "substance" expresses the absolute self-sufficiency that entails the metaphysical unity of the real in the identity of modes and attributes (extension and thought, intellect and will): "Per substantiam intelligo id quod in se est et per se concipitur: hoc est id cuius conceptus non indiget conceptu alterius rei, a quo formari debeat" (Ethica, ed. Gentile, Bari 1933, p. 3). Hegel at this point unified Leibnizian dynamism and Spinozian unity in the conception of reality as "process" (cf. Phän. d. Geistes, Vorrede, ed. J. Hoffmeister, Leipzig 1937, p. 43).

English empiricism, on the other hand — in reaction to rationalism — by reducing substance to the function of "substratum," led to the dissolution of the very concept of substance. Starting from the nominalist principle that the principal value of reality belongs to immediate perception and that "ideas" are nothing but the mental "residue" of sensations, Locke affirms that substances are not properly knowable, nor is it possible to have a precise notion of them (cf. Essay, I, 4, 18; ed. J. A. St. John, I, London 1854, p. 196 ff.). Our knowledge of substance is therefore reduced to a "complex idea," entirely vague, of a certain unknown support of accidents (ibid., II, 23, 3; ed. cit., I, p. 424) and concretely to a "complication or collection of those several simple ideas of sensible qualities which we usually find united in the things called horse or stone" (ibid., p. 425): and this holds not only for material substances but also for spiritual substances and for our very soul or mind (ibid.).

To escape the deadlock, Berkeley (v.) denied the concept of material substance and with it the notion of substratum, the Lockean theory of "complex ideas," and the distinction between primary (v.) and secondary qualities: the existence of things is identified with their being perceived (esse est percipi); therefore the concept of material substance or substratum is contradictory (Principles, §§ 5-23). The only substance is the soul, which attests itself as the "cause" of the feelings, ideas, and notions that we continually experience or produce in ourselves (ibid., § 25). Finally Hume (v.), starting from Berkeley's reduction of spiritual substance to the concept of the "cause" of its own modifications, maintained that the notion of cause (v.) has no foundation either a priori or a posteriori in our knowledge, because we lack the corresponding impression. Cause, and with it substance, is reduced to a natural conviction (belief), to an instinctive feeling whose origin we do not know (Treatise on human nature, part 1, sec. 7; part 4, sec. 3; ed. Selby-Biggs, Oxford 1928, pp. 17 ff., 219 ff.; see also Appendix, p. 633).

In the metaphysics of immanence, substance is either absorbed without residue into the becoming of the Whole of reason or universal history (pantheistic monism) or is entirely resolved into that same residue which is the singular fact of becoming (phenomenalism); in the metaphysics of transcendence, on the other hand, substance has an absolute foundation in the "form" that structures the individual in time and space, and the form in turn is founded in the divine intellect, from which every essence draws its first origin.

Cornelio Fabro