PARTICIPATION. - Participation, or methexis (Gr. μέθεξις), as a philosophical concept receives its first determination in Platonism.
Plato uses the term: 1) (together with μετοχή, παρουσία: Phaed., 83 A, 100 D) to characterize the relationship between the things and properties of the visible world and the ideas that share their names. Sensible things possess, in what they contain of the intelligible, a participation, that is, an image (εἰώνων; Tim., 92 C) or imitation (μίμησις; Phaed., 74 A) of the pure essentiality of the ideas, limited and obscured by the conditions of contingent and mutable being; 2) in the metaphysical dialogues, especially in the Parmenides, Sophist and Statesman (together with πανωνία, μεῖξις), to describe the relations that exist among the ideas themselves according to the implications and presuppositions of their conceptual contents (μέθεξις τῶν γενῶν).
Aristotle, with his more critical sense for the differences between the real order and the logical order, rejects the conception of methexis in both senses defined above (Met., I, 6, 987 b 10-13; 9, 991 a 20-23). Only in the Topics, which for the most part belong to his Platonizing period, is the concept of methexis present, understood in a purely logical sense as a relation among predicables (v.) according to their degree of generality. In this same sense the term was taken up by Porphyry in his Isagoge in Categorias Aristotelis, which had a great influence on medieval logic.
The idea of participation, on the other hand, acquired particular importance in Neoplatonism (v.). The meaning of the concept became more precise and univocal, and was combined with a determinate schema of production or procession of the participating beings. It is characteristic, moreover, that participations follow one another according to a descending order which, beginning from the most universal and conceptually most fundamental forms, extends between the supreme and transcendent principle, the unparticipated, down to the empirical world. Sensible things come about through a kind of generation by which the "forms" ultimately produce, in matter, images and likenesses of themselves. These images, however, do not unite physically with matter, which therefore, properly speaking, does not participate in the forms (Plotinus, Enn., III, 6, 11-14). In pagan Neoplatonism this hierarchy of participations is produced as a necessary expansion of the first principle. Christian philosophers and theologians (Origen, St. Augustine, Pseudo-Dionysius, Scotus Eriugena) and Muslim ones (al-Kindi, al-Fārābī, Ibn Miskawayh, Avicenna, Avicebron) sought, in various ways, to reconcile the metaphysics of participation with the dogmas of God's freedom in his creation and of the immediate causal dependence of all creatures on God. In the writings of the young Origen the ideas, which prefigure the world, perhaps still represent a realm of beings produced by an eternal and necessary creation (De Princ., I, 8, 4; Hom. in Genes., I: PG 11, 146). Later Christian Neoplatonists, taking up a thought of Philo, conceived the forms as ideas immanent in the divine spirit and as divine perfections capable of being participated. Not all of them, however, succeeded in freeing themselves from the implications of the concept of emanative productivity which tends to conceive participation as a communion with a form or perfection which, in the last analysis, is identical with God himself.
The Scholastics, comparing their Neoplatonic sources with Aristotelianism, elaborated and refined the concept of participation. St. Thomas in particular detached it from association with uncertain imaginative elements or with explanatory schemas unjustly generalized, and clarified it in his theory of the formal analogies between divine being and finite being. He adopts a very formal definition of participation: « Est autem participare quasi partem capere et ideo quando aliquid particulariter accipit id quod ad alterum pertinet universaltiter, dicitur participare illud » (In Boethii De hebdom., ch. 2), a definition that leaves open the possibility of specifying the philosophical content of the idea of participation according to the order and mode of being to which it is applied. St. Thomas further clarifies it by combining it with the Aristotelian pair of potency and act (C. Gent., II, 53). In determining the relationship between God and finite beings, the distinction between « ens commune » and « ens primum », and between the transcendental perfections and the absolute and essential perfections subsisting in the divine being, eliminates the danger of pantheistic implications. The function of the idea of participation in this problem concerns in the first place its static-structural aspect, that is, the question of the possibility of multiple finite beings, substantially distinct from God, as regards their entitative constitution. The dynamic-causal aspect of the relationship is determined with concepts derived from the idea of creative action that proceeds from the wisdom, the free choice and the love of God. For the application of the concept of participation in the demonstration of the existence of God, v. Dio.