Sensism

SENSISM. - A philosophical system or tendency that admits sensation (v.) as the sole source of knowledge and resolves into it all the forms or functions of thought (v.). Sensism is therefore opposed to a substantial distinction between sense and intellect, between perception and concept (v.). It is distinguished from sensationalism, which understands reality itself, phenomenistically, as pure sensation, and from sensualism, which in Italian has an exclusively ethical meaning and indicates, with the same sense as hedonism (v.), the system that places the norm of morality in sensible pleasure. The terminology is more uncertain elsewhere: sensualism is in fact used, in French, German and English, with the meaning of sensism, a term that is lacking in these languages (recently W. Brugger introduced it [Sensismus] in his Philosophisches Wörterbuch, Vienna 1948).

Sensism represents in a certain sense the antithesis of rationalism (v.); deriving all knowledge from experience, it is opposed to the various forms of innatism (v.) and logically involves the negation of a theoretical knowledge valid beyond experience itself (positivism [v.]).

The first formulations of sensism, though with a meaning intended to be merely psychological, are found in pre-Socratic philosophy. Indeed, despite the epistemological dualism that emphasized the distinction between opinion or empirical-vulgar knowledge (βῆζα) and truth or rational knowledge (ἀληθε), in Parmenides the substantial identity between thought and corporeality is affirmed (Diels, fr. 16 B, I, p. 244, 8; Aristotle, Met., III, 5, 1009 b 21-25; cf. Gli eleati, edited by P. Albertelli, Bari 1939, p. 155). For Empedocles "thinking and perceiving are the same thing" (Aristotle, De anima, III, 3, 427 a 19-20; cf. Met., III, 5, 1009 b 12-13), and according to Protagoras "the soul is nothing apart from sense" (Diogenes Laertius, IX, 51; cf. Plato, Theaet., 152 a, c): this sensism of Protagoras was posited as the premise of epistemological relativism, insofar as sensible perception, conditioned by the individual subjective-objective moment, has no value of universality. Stoic epistemology is also sensistic: "By means of the senses nature offers us the notions of things" (fr. 66: N. Testa, I framm. degli stoici antichi, I, Bari 1932, p. 36; cf. fr. 62, ibid., p. 32): experience, concepts and science have in sensation their sole source. Equally explicit is the sensism in the school of Epicurus (v.): "every rational knowledge comes from sensations" (πᾶς λόγος ἀπὸ τῶν ἀλόθηκων ἡρτησαι: Diogenes Laertius, X, 32). In early Christian thought Tertullian inclines toward sensism and, not without the influence of Epicureanism, Arnobius (cf. Adversus Gent., II, 16-20 ff.: PL 5, 833 ff.). Medieval thought, even in the nominalistic tendency of the 11th and 14th centuries, maintained the substantial distinction between sense and intellect, and therefore one cannot speak of sensism in Scholasticism: nevertheless the principles of sensism were latent in the devaluation of universal knowledge on the part of Occamism (v. NOMINALISMO; OCCAM). It is equally inaccurate to attribute sensism to Campanella (v.): he holds that the universal, as ideas and concept, if not as common notion, transcends sense: "homini... mentem divinam immitti, quandoquidem in eo apparent operationes quae non in caeteris" (Prodromus, Frankfurt 1617, p. 85, in G. Di Napoli, T. Campanella, Padua 1947, p. 278 ff.). In modern thought sensism presents itself first of all in Hobbes (v.): there is no distinction between soul and body, and therefore "all knowledge and science derives from sensation" (cf. Leviathan, I, 1 and 34), understood passively as motion of the organic subject toward the object; deterministic-mechanical association accounts for all psychic processes. Locke (v.), although he affirms that every idea comes from experience (Ess., II, 1, § 2), nevertheless goes beyond sensism, insofar as he recognizes, alongside sensation, as a source of knowledge "reflection" or the internal perception that the soul has of its own acts (ibid., 4 ff.). Sensism is associated with materialism (v.) in La Mettrie: the entire psychic life is a function of the brain and every content of knowledge derives from the senses and is resolved into sensations. In La Mettrie, as also in Helvétius (v.), sensistic materialism was translated, on the ethical plane, into hedonism: there is no other motive of the moral act than individual utility and interest, even if sought in obedience to the laws: to be "moral" is in the end nothing but a way of being happy. The most typical expression of sensism is found, in the French Enlightenment, in Condillac (v.). He accepts Lockean empiricism, but resolves into sensation also the second source of knowledge, "reflection": "la sensation enveloppe toutes les facultés de l'âme" (Traité des sens., I, 7, § 2). Every content of knowledge and all its functions are therefore nothing but elaborated and transformed sensations ("sensations transformées"): attention, abstraction, reflection, analysis, synthesis, imagination, comparison, judgment, syllogism are simple characteristics (vividness, persistence...) or relations (of concomitance, succession, coordination, similarity, distinction...) of sensations. Similarly in the affective field all feelings (love, fear, hope, desire, will for the good...) derive from the fundamental character of pleasure-displeasure, inherent in sensations. But, unlike La Mettrie (whose materialism, as Lange demonstrated in Gesch. d. Materialismus, I, part 1, ch. 2; Ital. trans. Milan 1932, p. 337 ff., does not derive from Condillacian sensism), Condillac maintains a spiritualistic tone for his sensism: he does not in fact exclude the existence of the spiritual soul, distinct from matter and motion, subject of sensations (cf. De l'art de raisonner, I, 3). Condillac's sensism as a systematic empiricism of the genesis and development of knowledge had wide success and became, in France, the official philosophy of the second half of the 18th century (v. IDEOLOGIA); among the "ideologues" Ch. Bonnet (v.) preserves a spiritualistic character for sensism. It was imitated in Italy by Romagnosi (v.), Soave (v.), Borrelli (v.). Subsequently sensism accompanies the developments of materialism: Robinet; Cabanis (there is no soul distinct from the body; psychic functions are resolved into nervous chemical processes [Diderot had understood them as mechanical processes]: thought as a secretion of the brain); Czolbe (consciousness is a pure copy of material reality and even its representations are endowed with extension, cf. Neue Darstellung d. Sensualismus, Leipzig 1856); Feuerbach (moral sensism: morality and action are directed solely by the pursuit of happiness, of which sensation is the criterion). Sensism is also associated with Humean empiricism (v. HUME): the power of the mind and of thought is, in the end, nothing but "the faculty of compounding, transposing, augmenting or diminishing the materials afforded us by the senses and experience" (Enquiries, sec. II, § 13, ed. Selby-Bigge, repr., Oxford 1932, p. 19); nor is it extraneous to the postulates and motives of positivism and neo-positivism (v.). It was combated in France by the spiritualistic tendency of Maine de Biran, Jouffroy, Cousin.

Sensism presents a positive claim already asserted by Aristotle against Plato's innatistic idealism and accepted by Thomism: the objective-functional dependence of the activity of thought on the forms of sensibility. The principle "nihil est in intellectu quod prius non fuerit in sensu" (cf. St. Thomas, De verit., q. 2, a. 3 ad 19) can have a correct acceptation, insofar as no object is actualized in thought without a relation, immediate or mediated, with the data of sensible knowledge: "sine sensu non potest aliquis homo addiscere, quasi de novo acquirens science, nor to understand, as one using knowledge already acquired" (St. Thomas, In De an., III, lect. 13, ed. Pirotta, n. 791). But this does not mean that the function of the intelligence is exhausted in the senses. The concept (v.) presents itself instead as an interpretation and emergence, on the plane of being and of its absolute principles, of the empirical content of sensation. The intellect therefore manifests an essential noetic transcendence, as a discovery of the meaning and of the universal values of experience. Sensible knowledge therefore does not count as an adequate principle of conceptual elaborations: it is not, as St. Thomas puts it, "totalis et perfecta causa intellectionis, sed magis quodammodo est materia causae" (Sum. Theol., 1a, q. 74, a. 6, c., at the end). Equally irreducible to sense is the knowledge that thought has of itself as self-consciousness (v.) and reflection (v.).

Sensism involves, in its developments and systematic demands, on both the theoretical and the practical plane, relativism (v.).

Ugo Viglino