DISTINCTION. — In its broadest sense, distinction is the non-identity of something in relation to another: life and human knowledge, insofar as they involve a multiplicity of situations and objects and a process of development on the part of the subject, presuppose the existence of distinction and the possibility for human consciousness to recognize II.
Thus, distinction presents itself in all spheres of consciousness and knowledge: in perception, in scientific and philosophical knowledge, in moral reflection, in theology, and in revealed faith. In each of these spheres, distinction is determined within its own type of attribution, that is, according to the relationships of identity and opposition characteristic of the object of the sphere itself. In this way, it is possible to have, simultaneously and with respect to the same thing, a multiplicity of predications which, from one aspect, affirm identity and, from another, distinction. This depends in part on our intellect, which can grasp different aspects of a thing and form a unified overall understanding of many things above their particular differences. It is in this way that distinction is found in philosophical thought, which, starting from immediate empirical and pragmatic knowledge, proceeds to distinctions and oppositions in order to rise to considerations of a higher synthetic nature that culminate in the Supreme Principle, both in the logical order (principle of non-contradiction) and in the ontological order (God). Distinction is therefore not simply separation or absolute otherness, but rather indicates the presence of an opposition between objects that, while opposed, nonetheless belong or are found within the same sphere of being and knowing.
Firstly, there is distinction in the field of perception (sensitive and spiritual), in which lived experience unfolds, and one can speak of distinction both of acts and of objects. The distinction of acts pertains, in itself, to the concrete objects to which such acts are applied. The distinction of objects, on the other hand, is a function of the unitary and total content they present to consciousness, as shown by the *Ganzheitspsychologie* (Krüger’s School) and *Gestaltpsychologie* (Wertheimer, Köhler, Koffka, Levin, etc.) in opposition to associationist psychology.
Distinction in the metaphysical field is a function of the conception of reality proper to the various philosophical schools. In monistic metaphysics, whether realist or idealist, unity represents the very form of reality in its ultimate condition, while distinction is reduced to mere appearance or phenomenon (*Erscheinung*). For Plato, there is the formal distinction of the “kinds” and separate forms; for Spinoza, that of the modes and attributes of the single Substance; for Hegel, that of the “forms of Spirit” (art, religion, and philosophy) and their stages of realization, etc. In dualistic or pluralistic metaphysics, distinction depends on the criterion adopted to isolate the different subjects of being and the different objects of knowledge: thus, one may have an atomistic pluralism (Democritus), a monadistic pluralism (Leibniz), or a formal pluralism (Platonism and Neoplatonism, from which derive medieval positions with a formalist background, not only of Scotus but also of the Augustinians and even authors close to the highest like Giles of Rome, who attributes an *esse* to every formal aspect of a being). In Aristotelianism, metaphysical distinction is based on the rigorous opposition of contradiction and is always a real distinction in its order: the distinction of matter and form in corporeal essence, of essence and act of being in finite being, of creator and creature within the realm of being as such, of substance and accident in the sphere of existence, and of cause and effect in that of becoming.
In the sphere of pure logical thought, distinction concerns the relationship between concepts: it is governed by the doctrine of the five “predicables” of Porphyry (genus, species, difference, property, accident). Logic, for St. Thomas, has value insofar as it is grounded in and corresponds to a real distinction: thus, the distinction of genus and difference in the definition of a natural body is founded upon the real distinction of matter and form in bodies or at least upon that of essence and act of being, common even to spiritual substances (cf. *Contra Gentiles*, II, 95).
In the theological sphere, distinction has its sole foundation in divine Revelation: the real distinction of the divine Persons is based on the relationships (“relationes subsistentes”) that define the terms of Father, Son, and Holy Spirit (*Summa Theologiae*, I, q. 29, a. 4); whereas the distinction between the divine attributes is only a distinction of reason, since they are identified with the formal plenitude of the divine essence (ibid., q. 4, a. 2).
In general, in every field of human knowledge one can speak of distinction, but its meaning depends on the ultimate reference that can be given to II. Thus, one may speak of spatial and temporal distinctions, real and intentional, natural and supernatural, insofar as the being within which one moves belongs precisely to a well-defined sphere that, in its presentation, contains the criterion of distinction itself (perceptive, metaphysical, logical, natural, supernatural, or revealed).