ANTINOMY. - From the Greek ἀντίνομος (ἀντί against, νόμος law) is the contradiction or inconsistency of a law, which gives rise to interpretations in opposite senses; or else the contrast, real or apparent, between two different laws (Quintilian, VII, 7, 1; ibid., 10, 2). In a derived and now common sense, a. means in general contradiction, conflict, inconsistency, arising from situations, principles, or reasoning that appear equally legitimate (practical, social, historical antinomies, etc.).
In Kant, a. are the contradictions into which human reason falls when it considers the contents of its ideas (which are valid only as unifying representations of experience) as possible objects of science (metaphysics). They concern in particular the cosmological idea and are formulated by Kant in the form of theses and antitheses both susceptible of equal demonstration. Kant enumerates four which together constitute “the a. of pure reason” (cf. Kr. der r. Vernunft, Die Trasc. Dial., II, ch. 2; Italian trans., Bari 1942, pp. 335 ff.). Kant also admits an “a. of practical reason” (in the concrete of the highest good, an indissoluble agreement between virtue and happiness is essential; yet in the natural world the realization of virtue is not conjoined with happiness: cf. Kr. der prakt. Vernunft, part 1, II, ch. 2; Italian trans., Bari 1942, pp. 136-37); an a. of teleological judgment, concerning mechanism and finality, and finally an a. of aesthetic taste (cf. Kr. der Urtheilskraft, §§ 56 ff. and 69 ff.; Italian trans., Bari 1938, pp. 193 ff. and 246 ff.). V. KANT.