THOUGHT. - From the Latin *pensare*, to weigh, to ponder (though it has another derivation from the Greek *νόησις*, *δέουσα*), the term retains its etymological reference in one of its most proper meanings today, as the reflective activity of the intellect (cf. v.). Although less frequent, the use of *pensare* in the sense of "to consider," "to weigh in the mind," is not absent in classical Latin: *"vulnera laude pensabimus"* (Quintilian, *Declam.*, 3, 16; cf. E. Forcellini, *Lexicon totius latinitatis*, III, Padua 1940, p. 625). However, our modern "to think" is more accurately rendered by *cogitare* (from *cogere*, a contraction of *coagitare*, meaning almost "to gather and weigh mentally"), where a certain semantic parallelism with *pensare* in the sense of "to ponder" is present (cf. op. cit., I, ibid., p. 672).
In a very broad sense, after Descartes—though not exclusively so in his usage—it denotes every conscious activity of the spiritual being: *"What is a thing that thinks? It is a thing that doubts, that conceives, that affirms, that denies, that wills, that does not will, that also imagines and that senses"* (*Meditations*, II; Italian trans. by A. Tilgher, I, 2nd ed., Bari 1928, pp. 98-99; cf. *Principles of Philosophy*, Part I, § 9). In a narrower sense, it is sometimes coextensive with cognitive activity, thus excluding the acts of appetitive-volitional faculties. In the more proper sense, common to contemporary Neoscholasticism, it refers solely to every moment of intellective-rational knowledge—that is, the spiritual perception of universal values, causes, principles, reasons, purposes, relationships of being and things. It thus includes, along with the concept (cf. v.), the fundamental acts of judging (cf. V. JUDGMENT) and reasoning (cf. V. REASON; REASONING), and constitutes the constitutive activity of science, philosophy, and, in part, ethical-legal-economic praxis, religion, and art.
Taken in this sense, it may be affirmed that thought always implies knowledge (cf. v.), if knowledge is understood in a generic sense as the presence of any datum to consciousness. But thought is not altogether convertible with knowledge if the latter is understood as an actual perception of being and reality. The activity of thought, by virtue of its (relative) spontaneity, may indeed turn toward immanent and subjective constructions that do not correspond, in whole or in part, to reality: *"in abstract concepts, in thoughts, in words, everything imaginable enters, therefore also the false, the impossible, the absurd, the nonsensical"* (A. Schopenhauer, *The World as Will and Representation*, Supplement, I, ch. 6; Italian trans. by G. De Lorenzo, II, Bari 1930, p. 85). Hence, Kant’s assertion finds justification: *"To think an object and to know an object is not the same thing"* (*Critique of Pure Reason*, Transcendental Logic, § 22). Although Kant’s further thesis—that the categories have no use in the knowledge of things unless these are taken as objects of sensible experience—is by no means demonstrated (ibid.), it may be expressed otherwise: human thought operates in vain unless it refers to an object of empirical intuition (cf. V. KANT; OBJECTIVISM).
In idealism (cf. v.), thought is the structure and essential ground of reality, which, by its intrinsic and absolute spiritual significance, is entirely resolved into thought. In Marxism, thought is merely the subjective expression of the objective-dialectical processes of eternal matter. In Bergson (cf. v.), thought is one of the directions in which the vital force or *élan vital* of reality develops. Without adopting the idealistic equation *being = thought* or the total naturalistic dissolution of thought itself, it may be said, in a realistic sense—albeit with an improper use of the term—that all of nature and reality is thought, insofar as it is the expression and effect of Absolute Rationality and the concrete actualization of ideal moments and processes (cf. the cosmic and psychic thought of Blondel).