In philosophy the term (Gr. ἀνάγνωσις) had a technical meaning in Platonism, where it denoted the process of the mind from sensible perception idea (v.): “It is proper for man to understand by means of the idea (εἶδος), which from many sensible representations arrives at rational unity: and this is nothing other than r. (ἀνάγνωσις) of those things which our soul has once seen, when it was in the train of a god” (Phaedr. 249 c; cf. ibid., 250 a; and Men. 81 c, 86 a-b). In Aristotle, the gnoseological-metaphysical meaning of Plato fell into disuse (which, it seems, was later taken up in early Augustinian thought: cf. Ch. Boyer, L'idée de vérité dans la philosophie de St Augustine, 2nd ed., Paris 1941, pp. 213-15), and r. is understood in an exclusively psychological sense. Unlike memory (μνήμη), which is the passive preservation and recognition of prior contents of consciousness, r. is the active process of recalling and reviving the past. It is therefore a kind of search (ζήτησις τις) and almost a kind of syllogism (συλλογισμός τις), whereby, whereas memory belongs also to brute animals, r. is proper to man who possesses the faculty of deliberation (De mem. et remin., ch. 2, 253 a 7 ff.; cf. commentary of St Thomas, lect. 8a, ed. Spiazzi, Turin 1949, no. 398 ff., and Sum. Theol., 1a, q. 78, a. 4). This distinction, however, is secondary, inasmuch as, granted the evident active character of human memory, r. may be understood as memory in act, according to the psycho-physical laws (which include the directive power of the self-conscious subject) conditioning the association of contents of consciousness.
The Aristotelian sense, though not entirely lost (it has been taken up, among others, by Rosmini), is today quite rare and has in fact yielded to an opposite meaning. According to E. Baudin (Corso di psicologia, Italian trans. by G. Lorenzini, Florence 1948, p. 283), r. is an evocation without recognition, i.e. an unconscious recall, of memories already buried. This meaning is alive in ordinary language, which designates as r. the spontaneous reappearance in consciousness of data and representations (phrases, sayings, texts...) previously experienced but not recognized as such (unconscious r.). In common usage r. also means “uncertain, vague recollection”; but this meaning is generally not accepted in psychology.