Etymology: < classical Latin idea (in Platonic philosophy) eternal archetype, in post-classical Latin also form, image, likeness (from 8th cent. in British sources), image existing in the mind (13th cent. in a British source) < ancient Greek ἰδέα form, appearance, kind, sort, class, (in Platonic philosophy) general or ideal form, archetype, notion < the stem of ἰδεῖν to see (see wit v.¹) + -έα , suffix forming nouns. The Greek word is thus analogous in derivation and original sense to classical Latin speciēs species n. ( < specere to see, behold: see suspect v.). Compare later idee n.In later use influenced semantically by Anglo-Norman idie, Anglo-Norman and Middle French idee, ydee, French idée (c1119 in Anglo-Norman), whose principal senses include: ‘visible and distinctive form of an object, archetype’ (c1119), ‘eternal archetype, existing only in the mind, of objects which can be apprehended with the senses’ (1370), ‘conception or notion of something to be done or carried out’ (1458; apparently rare before the late 17th cent.), ‘image, form, likeness’ (1487, glossing post-classical Latin idea ), ‘perfect beauty as embodied in a beloved lady’ (mid 16th cent.; compare sense 3b), ‘image of an object as perceived by the senses’ (1552), ‘mental image or notion of something previously seen or known’ (1564), ‘conception’ (1583), ‘ideal’ (early 17th cent.; now regional (Walloon)), ‘preliminary sketch’ (1610, originally with reference to a literary work), ‘whatever is in the mind and directly present to cognitive consciousness’ (1637 in Descartes, in the passage translated in quot. 1649 at sense 12b), ‘something merely imagined or fancied’ (1651; compare the similar sense ‘daydream’ (1672; rare), and earlier par idée ‘in imagination’ (1616), en idée (see in idea at Phrases 1)), ‘sum of a person's thoughts and judgements which constitute an opinion’ (1662), ‘musical theme, phrase, or figure as conceived or sketched before being worked up in a composition’ (1866 in idée musicale ). Compare Catalan idea (14th cent.), Spanish idea (early 15th cent.), Portuguese idéia (c1543 as †ydea , 1548 as †idea ), Italian idea (beginning of the 14th cent.); also Middle Dutch ydee (1465; Dutch idee ), German Idee (17th cent.; 1528 in Latinate form idea ), Swedish idé (beginning of the 18th cent.; also †idee , †idée ). The term first entered the modern European languages in senses which were either identical with, or very similar to, the Platonic sense (see branch I.); sense 3 shows semantic overlap with ideal n. The later semantic development is characterized, in English as well as in other European languages, by two tendencies. On the one hand, a gradual semantic generalization and popularization of the originally philosophical term took place, leading to partial synonymy with concept n., notion n., thought n., etc. On the other hand, philosophers from Descartes onwards developed new senses of the term (see branch III.). Broadly speaking, the specific philosophical uses in sense 12b developed out of the uses of the word in branch III., and represented a break with the Platonic tradition in that ideas were now considered to be perceptible by the senses or present in the mind as the natural objects or contents of human cognitive consciousness in general. On the other hand, the uses in sense 1 arose by extension of Platonic uses. Sense 1b is largely after Kant's use of German Idee (1781 (in his Kritik der reinen Vernunft) or earlier); in the relevant chapter of that work, entitled Von den Ideen überhaupt , Kant begins with a critical discussion of Plato's concept of the idea, and goes on to adapt this. Sense 1c is after Hegel's use of German Idee (1830 (in ed. 3 of his Enzyklopädie der philosophischen Wissenschaften im Grundrisse) or earlier). With in idea at Phrases 1 compare Spanish en idea (c1500; first half of the 15th cent. as en la idea ; also frequently with possessive pronoun: en su idea , etc.), French en idée (1643). With to have no idea at Phrases 2 compare French n'avoir aucune idée (1815 in colloquial use; already in 17th cent. in philosophical contexts in sense ‘to have no conception or understanding of (a problem)’; compare sense 11a). In form ideie apparently influenced by French; compare later idee n.

Etymology: < idea n. Compare earlier ideate v.