ILEMORFISMO. — From ὅλη (matter) and μορφή (form), it denotes the philosophical theory, due to Plato and Aristotle, which holds that corporeal substance is composed of an indeterminate element (matter) and a determinate one (form).
The first Greek philosophy, through its attempts to explain becoming, prepared the way for hylomorphism. Against the mobilism of Heraclitus, Parmenides asserts immobility: “For being exists, whereas nothing does not exist” (frg. 6, 1-2); this being is immobile. Indeed, change is either from being or from non-being; but both are impossible, “since neither can being come to be (for it already is), nor can anything come to be from non-being; οὔτε γὰρ τὸ ὄν γίγνεσθαι (εἶναι γὰρ ἦδη), ἐκ τε μὴ ὄντος οὐδὲν ἂν γενέσθαι (Aristotle, Phys., I, 8, 191 a 30-31). Nothing, therefore, comes into being; nothing changes. This dilemma had an impact on later philosophers, who attempted to break II. Empedocles and Anaxagoras explain cosmic becoming mechanistically; so too do Leucippus and Democritus, for whom “the full and the solid is being, the void is non-being,” and therefore “being exists no more than non-being, since the full exists no more than the void” (id., Met., I, 4, 985 b 7-9). The parts of being (the full) are atoms, indivisible (ἔτομος) and impassible (ἐπαθής) like the being of Parmenides, differing from one another in figure, order, and position: their movement in the void and their mingling account for becoming (ibid., 985 b 5 ff.).
Plato explains the mutability of worldly things through a χώρα that is “difficult and obscure,” almost “a receptacle (ὑποδοχήν) of that which comes to be, as it were a nurse” (τῆναι, Tim., 49 a), which has no form in itself but receives all forms, which are images of the immutable ideas. The body results from the union of the χώρα and an image of the ideas. Aristotle, taking the existence of becoming as evident (Phys., I, 2, 185 a 13-14), observes: just as, when a man becomes musical, the man who is the substratum remains, while the non-musical disappears (ibid., 7, 190 a 95 ff.), so in every change there is the substratum that remains, the privation of the form, and the form: δῆλόν ἐστιν ὅτι δεῖ ὑποκείσθαι τι τοῖς ἐναντίοις καὶ τάνναγίοι δύο εἶναι (ibid., 191 a 4-5). With these concepts Aristotle proposes a first solution to the Parmenidean dilemma, subsequently developed on the basis of the doctrine of potency and act (ibid., 8, 191 b 27-29). A reality becomes actually something insofar as it possessed a real subjective capacity or potency to become it; hence, between non-being in the total sense (μὴ ὄν) and being in act (ἐνεργεῖς ὄν) there is being in potency (ὀνόμει ὄν). Change occurs neither from μὴ ὄν nor from ἐνεργεῖς ὄν, but from ὀνόμει ὄν: “Since being is twofold, everything changes from being in potency to being in act ...; everything comes to be from being, that is, from being in potency, and from non-being in act” (Met., XII, 2, 1069 b 15-20). Aristotle applies these notions to substantial becoming, which presupposes an indeterminate substratum, the ὀνόμει ὄν in the substantial order, called prime matter (ὅλη ἡ πρώτη, ibid., V, 6, 1017 a 5), the privation of determination (ὑτέρησις), and substantial determination, called form (μορφή): “In all changes between opposites, there is something that serves as their substratum ... And likewise in substantial changes: there is something that is now in generation and now in corruption, now a determinate substratum and now according to privation” (ibid., VIII, 1, 1042 a 32-63). Corporeal substance is therefore composed of matter and form: γίγνεται πᾶν ἐκ τε τοῦ ὑποκειμένου καὶ τῆς μορφῆς (Phys., I, 7, 190 b 20). S. Tommaso comments: “Omne quod fit, est et fit ex subiecto et forma... Et notandum est quod hic intendit inquirere principia non solum fiendi sed etiam essendi: unde signanter dicit: ex quibus primis [principiis] sunt et fiunt” (Phys., I, lect. 13; cf. Met., VIII, lect. 1, ed. M. R. Cathala, Torino 1915, pp. 488-89, n. 1689).
Prime matter is wholly indeterminate in principle: “I call matter that which in itself is neither a determinate thing, nor a quantity, nor any other of the determinations of being” (Met., VII, 3, 1029 a 20); “materia, secundum suam substantiam, est potentia ad esse substantiale” (s. Tommaso, Phys., I, lect. 15). Substantial form, on the other hand, is the principle that confers the first specific being and ontological unity upon the composite. Matter and form are therefore not beings (ens quod) but principles of being (ens quo). Form, moreover, does not exist prior to and independently of matter, but arises from matter’s own potentiality in the process of its becoming, “in quantum materia, quae est in potentia ad formam, fit actu sub forma, quod est facere compositum” (s. Tommaso, In Met., VII, lect. 7, ed. cit., n. 1423).
Hylomorphism, understood in various ways by the Greeks, Arabs, and Latins, and first clarified in its true sense by S. Tommaso (cf. P. Hoenen, Cosmologia, 3ª ed., Roma 1945, p. 274), is instead misconstrued by Duns Scotus, who maintains that prime matter can exist separately (Op. Ox., I, II, dist. 12, q. 2, n. 3; VI, ed. L. Wadding, Lione 1539, p. 682; cf. ibid., n. 4, p. 682). Likewise by F. Suárez (Disp. Met., d. 13, s. 4-5). R. Descartes (Epist. ad Regium, ed. C. Adam e P. Tannery, Parigi 1897-1910, III, pp. 502, 505-506), P. Gassendi (Physica, I, sect. 1, I, VII, cap. 3, Lione 1658, p. 469), G. Leibniz (Essais de théodicée, I, nn. 87-89; VI, ed. C. I. Gerhardt, pp. 149-51), E. Zeller, Philosophie der Griechen, II, II, 4ª ed., Berlino 1876, p. 347 ff.), and many others (cf. P. Hoenen, De origine formae materialis, Roma 1932) do not understand the notion of form as ens quo, nor, consequently, the “eductio formae e potentia materiae.” Various philosophical systems deny hylomorphism (mechanicism, atomism, dynamism, positivism, phenomenalism, idealism, etc., V. queste voci) for general metaphysical reasons.
Assuming the objective reality of extended bodies, not a few authors base hylomorphism on the Aristotelian argument concerning substantial change. Following the difficulties raised by scientific atomic theory, others attempt to derive hylomorphism from the fact that the body is a spatiotemporal reality, with energetic and inertial properties. They maintain that the actual unity and potential multiplicity of the continuum cannot be adequately explained without admitting in corporeal substance a principle of unity and determination (form) and a principle of multiplicity and indetermination (prime matter; cf. s. Tommaso, C. Gent., II, cap. 65; P. Descoqs, Essai critique sur l'hylémorphisme, Parigi 1924, p. 237). An analogous argument is drawn from consideration of corporeal existence, which possesses both unity and diffusion through time (cf. F. Renoirte, Éléments de critique des sciences et de cosmologie, Lovanio 1947, p. 227). Finally, hylomorphism is further validated by the twofold and opposing series of properties of corporeal substance: on the one hand quantity and energy, on the other quality and activity (electromagnetic forces, etc.; cf. P. Descoqs, op. cit., p. 269 ff.). These last three considerations are interconnected and may be regarded as a single foundation of hylomorphism, viewed from different perspectives that complement one another. Other authors, assuming as evident the principle that pure act is one and infinite and is multiplied when participated in by a potential subject, infer from the fact that there exist several corporeal individuals of the same species that these bodies are composed of a participated substantial act and of a substantial potency that receives it (cf. s. Tommaso, De spir. creat., a. 1, ad 9; Phys., VIII, lect. 2). The argument is much debated, since others maintain that the principle of participation is founded on hylomorphism.
Hylomorphism seems to be opposed by modern science, according to which matter is constituted by particles that some physical theories regard as ontologically distinct and at times also spatially distant. In this regard, it is observed that, if bodies were really to be understood as aggregates of particles (and therefore of distinct individual entities), hylomorphic theory could be applied to them. It does not in fact seem possible to admit, as some maintain (s. Alberto Magno, P. Descoqs, M. Fatta, etc.), that the particles, while remaining unchanged, are taken up by a higher substantial form into a substantial metaphysical unity, nor that metaphysical unity can consist in physical discontinuity. But the activity of the living body strongly persuades us of its substantial unity, from which it follows that substantial changes occur both in the assimilation of food and in the destruction of the living being following death. This argues, in the elements taken up into the unity of the living being and, by extension, in bodies generally, for the essential composition of matter and form.
In physics itself, if one sets aside theoretical constructions, observations of nuclei, atoms, and crystals, understood in their concrete experimental value, indicate a heterogeneous particulate constitution (that is, one with different properties in different parts) of matter; hence it is not necessary to think of the particles in the compound as distinct ontological individuals (cf. P. Hoenen, Cosmologia, pp. 316 ff.). In the atom, in chemical compounds, and also in crystals, a heterogeneous continuity is therefore possible, permitting the ontological substantial unity of higher bodies. Moreover, the very recent physical theory of quantum mechanics, by rejecting the intuitive notion of the corpuscle as a material point, rejects the mechanical theories of discontinuous matter, that is: “it rejects the presupposition, inherent in all preceding theories, that atoms, photons, and the other entities of the atomic world should be conceived as bodies or mechanisms of immense smallness” (E. Persico, Fondamenti della meccanica atomica, Bologna 1945, p. 68, cf. p. 87). Consequently, it asserts that the corpuscle, for example the electron, upon entering into higher complexes, loses its physical individuality, since it can no longer be identified and followed, and remains as a modification of the complex. “The property of individuality in this case corresponds to no physical reality” (ibid., p. 467; cf. P. Langevin, La notion de corpuscules et d’atomes, Paris 1935); L. De Broglie (Materia e luce, Milan 1940, p. 274) writes: “In quantum physics, the system is a kind of organism within whose unity the constituent elementary units are almost absorbed.” This concept is similar to that of the virtual existence of the components in the compound, developed by Aristotle and s. Tommaso. It may therefore be concluded that physical experiments do not seem to exclude hylomorphism and, in particular, that quantum mechanics develops concepts favorable to II.
By analogy with the concepts of hylomorphism, people often speak of matter and form in disparate fields. E. Kant generally calls the manifold matter, while form is that by which the manifold is ordered (cf. Critica della ragion pura, Italian translation by G. Gentile and G. Lombardo-Radice, Bari 1945, p. 64). There are “forms” of intuition—external (space), internal (time)—of thought (categories), of pure reason (ideas), etc.
In sacramental theology, the masters of the twelfth and thirteenth centuries formulated the general doctrine according to which every Sacrament, insofar as it is a sensible sign, is composed of things (res) and words (perba). Guided by analogy, and observing that the res has an indeterminate meaning whereas the words have a precise sense, they called the former the “matter” and the latter the “form” of the Sacrament.