CONTINGENZA. — In its generic meaning, c. is that which occurs “as necessary as it is unnecessary or possible” (Aristotle, Anal. Pr., I, 3, 25 a 37). In philosophical usage it indicates the contrary of what is necessary and is therefore almost synonymous with “possible,” with “that which may or may not be,” within the sphere of thought, being, or becoming. Waitz maintained a clear distinction between “possible” and c., but the view defended by H. Maier (Die Syllogistik des Aristoteles, I, Tübingen 1896, p. 194) prevails, namely, that Aristotle uses the two terms as synonyms (Anal. Pr., I, 10, 13, 15, 21; Anal. Post., I, 6, 74 b 38), and that the criteria given for one are those given for the other (Anal. Pr., I, 13, 32 a 18; Physic., VIII, 1, 243 a 11; Met., X, 3, 1047 a 26). The only difference is that c. emphasizes more strongly the fact that possibility is rooted in a real “δύναμις” (cf. W. D. Ross, Aristotle's Metaphysics, II, Oxford 1928, p. 245).
In logic, propositions in which the connection between subject and predicate is indifferent are called contingent: “man is white,” “Socrates walks” (Anal. Pr., I, 13, 32, a 18). In metaphysics, a distinction is made between c. in existence and c. in operation; all the modalities of c. are reduced to two roots, “matter” for bodies and “freedom” for spiritual substances. If everything were necessarily determined, the mechanists and fatalists would be right, but this is not so (De Interpr., 9, 19, a 7 agg.). Since “prime matter” is pure potency, it is and remains in itself disposed to receive all corporeal “forms.” When, therefore, it is under one form, it is not bound to it forever, but remains in potency to all the other forms, under which it can in fact successively pass when, through the action of contrary qualities, the body is corrupted and a new substance is generated. C. is therefore synonymous with “corruptibility”: “Quod aliqua quandoque sint et quandoque non sint, habent ex materia in quantum subiectum privationi vel formae” (s. Thomas, Comm. in De Cordo et Mundo, I, lect. 29, ed. Parm., XIX, p. 75a). Therefore spiritual substances, which in Thomistic metaphysics are devoid of any matter, should not be called contingent but necessary (that is, immortal): “Ea vero quae ab eo sic producta sunt ut in sempiternum sint, habent potentiam et virtutem ad semper essendum et nullo modo ad hoc quod aliquando non sint” (ibid., p. 75b.; De Pot., q. 5, a. 3; C. Gant., II, 30): a doctrine that underlies the third way (Sum. Theol., 1ᵃ-2ᵃc, q. 3). The neo-Scholastics generally adhere to the vague Wolffian meaning of c., as a synonym for that which is finite and created.
One speaks of “c. in operation” both in the corporeal and in the spiritual order. Intelligent substances whose adequate object of operation and striving is the universal Good remain “free” with respect to finite particular goods and means not necessary for the ultimate end. But contingent causes are also found in the corporeal world. Whereas some effects proceed of necessity (naturally), because they are characteristic of a given nature, that nature is indeed inclined toward others, but may be impeded by the intervention of another cause; with respect to still others, it possesses only a remote potency and is determined to neither one nor the other except through the convergence (concursus) of other causes, or through the occurrence of certain precise conditions, which are likewise contingent (s. Thomas, Comm. in Periherm., I, lect. 13-14, ed. Parm., XVIII, p. 30 agg.). This is what is said to occur according to “chance” (in natural events) or “fortune” (in human affairs).
Boutroux (v.), with the aim of safeguarding human freedom, proposed a “philosophy of c.” according to which, in the world
both of bodies and of spirits, there is no law that
is an absolute necessity: “The supreme principles of things
would still be laws, but moral and aesthetic laws,
expressions more or less immediate of divine perfection,”
which is pure and perfect “spontaneity,” in which all creatures
participate, although in different forms and degrees (p. 169).
BBL.: H. Bonitz, Index Arist., Berlin 1890, 249 a 30 ff.;
J. Maritzin, Sept leçons sur l'être et ses premiers principes, Paris
n.d.; E. Boutroux, De la contingence des lois de la nature, there
1905; E. Troelts, Die Bedeutung des Begriffs der Kontingenz
(Grs. Schriften, 2), Tübingen 1922, p. 769 ff.; M. Freudlich,
Zur Entstehung des Terminus « contingens », in Philos. Jahrbuch,
47 (1934), pp. 432-40; C. Fabro, La nozione tomista di c., in
Riv. di filos. neoscolastica, 30 (1938), pp. 132-49.