INTUITION. - From the Latin intueri (Gk. εἰσπρέω), to see, to look within, to contemplate, it indicates, etymologically, vision, a look, with a sense, for the most part, of penetration and intensity. But already in classical usage the term was transferred from the visual sphere to indicate intellectual perception: " nuentis aciem seipsam intuens " (Cicero, Tusc., I, 30, 73). And this is the principal reference that the term has preserved in the Neo-Latin languages (German Anschauung also tends toward it), albeit with a multiplicity of meanings, particularly in philosophical usage.
In current language, i. has the double meaning of: a) an original and profound perception of a reality, a truth, a value, a principle, a fact, e.g. the Platonic, Galilean, Einsteinian "i."; b) a ready and instantaneous knowledge or perception both of theoretical-abstract truths and of practical-concrete facts or relations. In this sense common usage opposes the "intuitive type," who grasps at a stroke, from simple clues, the meaning of a fact or problem, the exact value of a situation, to the "discursive type," who requires a slower process of analysis, comparison, deduction. Scientific discoveries (laws, hypotheses) and in general the inventive and creative moments of thought, although often following prior analyses and conceptual elaborations, are for the most part referred to i. in the twofold sense indicated. A reference to the common acceptation may be found in Aristotle, who opposes ἀγγύνοια, sagacity, readiness of intuition, to εὐβουλία, prudent counsel (Eth. Nic., VI, 9, 1142 a 31 ff.) and says of εὐστοχία (= sureness of i.) that it occurs without discourse and is something sudden: ἄνευ τε γὰρ λόγου καὶ ταχύ τι ἡ εὐστοχία (ibid., 1142 b 3).
In philosophical usage five principal acceptations of i. may be distinguished. 1) With a predominantly logical reference, i. is the direct and immediate knowledge of principles (theoretical, practical, moral) and evident truths (the reference to "evidence" is bound up with the primitive meaning of the term: " intueri," to see), in opposition to derived, mediated, logical-discursive knowledge. The term is used in this sense by Locke, Leibniz, Descartes. Connected with this, though with a predominantly gnoseological reference, are the Platonic-Plotinian sense: i. as direct apprehension of the intelligible in itself; the Augustinian-Bonaventurian sense: i. as immediate contact of the mind with truth, direct apprehension of the " rationes aeternae " or absolute values; the Rosminian sense: i. as the immanent and essential relation of the intelligence with its fundamental object, the idea of being (cf. Teosofia, V, national ed., Rome 1939, p. 20). 2) I. as direct perception of the existing, of the individual, of the concrete, in opposition to abstractive, representative, universal knowledge: a sense of Kantian derivation, frequent today; to this is related the technical acceptation held by some to be proper to Thomism: i. as perception (in sensible knowledge) of the real without intentional mediation, and i. (in the beatific vision) as union of the intellect with the divine essence in itself, without mediation of a mental word. 3) I. as sympathetic and instinctive compenetration into the intimate depths of reality and life, in opposition to external and fragmentary knowledge through conceptual determinations. This is the Bergsonian sense (cf. L'évolution créatrice, 77th ed., Paris 1948, pp. 176, 179). The Husserlian sense may be approximated to it, although it carries a different metaphysical meaning: i. as vision of essences, Wesenschau. 4) I. as the productive process of the first forms of the spirit's theoretical activity. This is the idealistic sense, already foreshadowed by the Kantian pure i. (the i. of space and time as a priori forms of the spirit: cf. Critique of Pure Reason, Transcendental Aesthetic, § 1, Ital. trans., Bari 1940, p. 63). From it derives the aesthetic reference developed by Croce: i. as the originating activity of the spirit, creative and expressive of pure images (words, colors, sounds, forms). 5) In a religious-mystical sense (and it could have analogous applications in other fields): i. as apprehension of God and the divine that is predominantly affective and therefore distinct from purely logical-rational religious knowledge.
The theory of i. (for its historical developments v. INTUIZIONISMO) presents two principal questions: a) whether and in what sense human knowledge can be called intuitive; b) what the gnoseological-metaphysical meaning of i. is.
a) I. in the sense of immediate perception of values, principles, relations, connections, intrinsic links between facts, concepts and principles, is a fundamental function of the intelligence; indeed, at bottom, it is the very essential power of thought to express in conscious apprehension the values of being. In this sense i. is the substratum of all fundamental noetic processes: ideation, judgment, reasoning. The idea (v.) in fact is not brought into act in thought except as i. of a value; the judgment (v.) in its cognitive moment is perception of the relation between subject and predicate; reasoning, both in the order of abstract truths and of concrete facts, is essentially intuitive perception of the logical nexus between premises and conclusion (St. Thomas distinguished between intellectus and ratio only in the sense that intellectus indicates immediate knowledge, ratio discursive knowledge: Sum. Theol., 1a, q. 59, a. 1, ad 1). The acceptation, not entirely fallen into disuse, of i. as a synonym for intellectual perception in general (cf. St. Thomas, I Sent., 3, 4, 5, c.; De Verit., q. 15, a. 1 ad 7) relates to this original meaning of knowledge as "vision" and "penetration" of an object, a value.
I. in the sense of perception or direct consciousness of the real, of the existing, of the singular, can be and is referred both to the senses and to the intellect. It must be made clear first of all that pure sensation cannot be equivalent to i. properly so called: an impression of color, sound or form, as such, is a pure lived state of consciousness, devoid both of apperception and of conceptual clarity and therefore of i. But pure sensation in man is scarcely to be found except at the very beginnings of existence. In the rapid development of consciousness it is soon clarified in the further perceptive processes (apprehension of objects as totalities and apprehension of the meaning that objects present for the subject), and intellective processes (apprehension of objects as categorial values). It is in this indissoluble sensorial-perceptive-intellective synthesis that the intuitive moment in human knowledge is realized. In fact the human intelligence, considered formally as pure power of thinking, does not have, as Kant well saw, an immediate relation to concrete reality, and therefore no direct i. of spiritual realities. But, besides being a power of abstract conceptualization and of logical discourse, the human intelligence is at the same time, by virtue of its immanent relation to sense, immediate consciousness of sensory-perceptual contents. In this its own proper function the human intellect is i. insofar as it posits itself as the assumption of concrete contents into the actuality of their own immanent intelligible value. The universal, which is the proper object of the human intelligence, is not, in the most genuine Thomism, the abstract universal, but the concrete universal, "in particulari existens" (Sum. Theol., 1a, q. 84, a. 7, c.). And since sensory data, by their very experiential positivity, count first of all as realities, the human intellect has, by way of its continuation with sense (which St. Thomas expresses with the well-known formula "conversio ad phantasmata": ibid., a. 7), an effective i. of the real and therefore of being, according to the various determinations that being itself assumes in sensory presentations. Herein lies the condemnation of every phenomenism (v.), insofar as human knowledge does not present itself as pure consciousness of phenomena, such as a knowledge enclosed within the sensory-perceptual sphere might be, but at the same time as i. of the phenomenon in its value as being. This radical i., in which the first actualization of thought consists, does not however reach the ontological meaning of being and therefore seems not to entail an equal i. of substance, which is a further concept elaborated upon the more complex contents of sensory presentations.
It appears, from what has been said, that i., even in the sense of perception of the existent and of the concrete, is not to be opposed to conceptual knowledge except insofar as "conceptual" is unduly identified with "abstract." The concept is always in the background of any perception or intellectual i.: every i. of the concrete is contested by categorical values more or less distinct; and indeed the more i. renders itself clear and objectively consistent, the more the concrete, from the objectual sphere of sensibility, is assumed, conceptually, into the deeper one of its real ontological contents. Modern irrationalism, therefore, which reduces the knowledge of values to sentimental, emotional, volitional moments, to which it attributes the meaning of i., in reality misconstrues the true concept of i.
I. as perception of the concrete and of the existent is not distinguished, at least in a broad sense, from reasoning. Indeed a dialectic of thought on the basis of essentially concrete data and connections is possible, and even frequent (intuitive reasoning): such is, for example, a medical diagnosis, a historical reasoning.
A second intuitive moment presents the intelligence as self-consciousness. As such, thought is in fact immediate perception of itself as act, process, consciousness. The whole psychic reality of the subject, and particularly thought and will (beyond the fundamental, though obscure and indeterminate, sense of our being, living and enduring), insofar as it is immediately present to consciousness, is i. in the most proper sense of the term, even if it does not of itself entail an equal i. of its own ontological principle, that is, of the I (v.). The I, therefore, may be said to be an object of i. in its psychological-operative consistency (intuitive certainty of the self and of one's own personal continuity), not in its metaphysical reality (cf. St. Thomas, De verit., q. 10, a. 8, c.). The domain of psychic-conscious reality is the only objectual sphere that does not entail, in knowledge, mental representation (the i. in the strict technical sense that some would wish to extend to the perception of sensible reality). Psychic reality in fact, insofar as it is an intrinsic determination of the I, has no real consistency outside consciousness, but is, in its very reality, a fact of consciousness, and therefore, when assumed into apperception, immediate i.
In the domain of religious knowledge — if one prescinds from the higher forms of supernatural experience, possible by the free gift of Grace — so-called mystical i. does not seem to be i. in the proper sense of the term. It in fact remains analogical and representative knowledge, although it reaches and stirs the deepest strata of the I, by way of the will and of love which unite the soul to God and pervade with their affective tone, in a certain manner transfiguring it, knowledge itself. Mystical knowledge therefore has a certain experiential value insofar as it is a reflection of religious experience itself (v.), the more vivid the deeper that experience is, but it does not of itself include a true i. of God. It implies an integrality of the direction of consciousness toward the supreme object of religious knowledge, not a perception of that object in itself.
In the domain of art the intuitive moment is present as conscious expression of images and forms in which the human spiritual world and its values are sensibly configured. It is therefore essentially a work of the imagination, but insofar as this is part of the living unity of the spirit and draws from the intense moments that the spirit unfolds in the order of intelligence and will the spiritual contents that it translates into images and forms. Aesthetic i. too, therefore, cannot be understood in its true nature and is indeed radically misrepresented if it is disjoined, as in Crocean thought, from intellective-conceptual knowledge.
Beyond the indicated forms of i., states of penetrating clairvoyance (v.) sometimes take place in the human consciousness — not yet fully explained either from the scientific or from the philosophical point of view — in which an intimate, though conceptually obscure, contact with the deepest values of reality is realized: the mystery of being (time, eternity, existence, duration, nothingness, becoming...) permeates consciousness with itself, causing that lofty sense of wonder and sometimes dismay, already known to Plato. It is perhaps principally in this order of experience that an objective foundation must be recognized for i. in the Bergsonian sense.
b) The gnoseological meaning of i. is revealed in two fundamental directions. As perception of the existent and of the concrete it is the solid phenomenological basis of realism (v.); as immediate perception of values, concepts, absolute principles, it includes in human thought a positive presence of the absolute, though not as a real term of i., but rather as supreme Value and condition of thought. It belongs to dialectic, which in the value of thought finds the indispensable bases for its every articulation, to determine the ontological meaning of the Absolute and its transcendence. It is in this essential dialectic that the perpetually living moment of i. in the Augustinian sense must be sought.