In Trinitarian theology notions are characteristics proper to each Divine person, by which man is able to know the Persons as distinct. These are innascibility, paternity, filiation, active and passive spiration (ST 1a, 32; Scotus adds the inspirability of the Second Person: In 1 sent. 28.1–3). The adjective notional is applied to whatever is proper to one Person and not common to all. In God "all is one, save where there is relative opposition" (Council of Florence; H. Denzinger, Enchiridion symbolorum, ed. A. Schönmetzer, 1330); therefore all that is notional is really identical with the divine relations of rigin, but man's abstractive mode of thought makes it necessary to introduce further mental distinctions if he is to think or speak of this mystery.
By the term notional acts theologians designate those divine acts that enable one to come to the knowledge of the distinct Persons; these are the generation of the word and the spiration of the Spirit. The magisterium unhesitatingly applies the corresponding verbs (generare, gigni, procedere ) to each Person (Fourth Lateran Council; Enchiridion symbolorum, 800, 804). Considered as the way by which the Persons and their opposed relations originate, these enable one to discern each Person. Some theologians speak simply of two acts (generation, spiration); the majority speak of four, considering each act both as emanating from a principle (active generation, spiration) and as received in a term (passive generation, spiration).
Certain conceptual problems arise (ST 1a, 40.4; 41.1–6). (1) One cannot think of origin save in terms of action, but, applied to God, man's concept of action must be purified of all created imperfection. God's immanent activity of knowing and loving is identical with His essence, pure act; one must exclude all idea of motion, passive potency, and determinability and speak simply of God's active power, exercise of activity, the active and actual influence of principle on term. Thus, by a mental distinction, one expresses the dynamic aspect of the relation of producing principle to term produced. (2) Notional acts are necessary, for God's activity is identical with His essence. This is not to suggest coercion; indeed notional acts are voluntary, not that the Father could have refrained from begetting the Son, but because God wills and loves all the perfection that He necessarily is. (3) Does the notional act presuppose (logically) the corresponding property, or vice versa? When one considers generation and spiration as received in the Son and the Spirit, the act is clearly prior to the property (filiation, passive spiration). Active spiration, common to two Persons, obviously presupposes those Persons. But what of active generation? This presupposes the First Person, constituted by the property of paternity. How can that property be logically prior to the act of generation? St. Thomas answers (ST 1a, 40.4 ad 1) by distinguishing between paternity as a property of the First Person (prior to generation) and as a relation to the Second Person (subsequent to generation).
See Also: properties, divine personal; relations, trinitarian; processions, trinitarian; trinity, holy, articles on
Bibliography: a. michel, Dictionnaire de théologie catholique, ed. a. vacant et al. (Paris 1903–50) 11.1:802–805. Commentaries on ST 1a, 41. Somme théologique: La Trinité, ed. and tr. h. f. dondaine, 2 v. (Paris 1942–46) 2:354–366. p. vanier, Théologie trinitaire chez saint Thomas d'Aquin: Évolution du concept d'action notionelle (Montreal 1953).