Cause

CAUSE. - I. NOTION. - According to the most reliable etymology, the first scientific application of the concept of c. would have been in the juridical sphere. Man would have sought c. in the order of human acts as the root of responsibility and imputability, before seeking it as a principle and constitutive element of the reality of being. According to Tannery (A. Lalande, Vocab. crit. de la philos., I, p. 100, note), while the Greeks emphasized the initial juridical moment of the "inquiry" and the accusation (αἰτειν, αἰτία, αἰτῶν), the Latins insisted on the central moment of the "defense" (canere, causa), from which the Neo-Latin terms connected with the Italian "cosa" also derive. An existential starting point also noted by G. Marcel: "Imputability, or rather the need to impute (to have something or someone with whom to come to dispute), would it not in fact be at the origin of every causal explanation?" (Être et Avoir, Paris 1935, p. 8).

It is to Aristotle, who was well acquainted with the juridical usage (H. Bonitz, Index, 23 a 35), that we owe the rigorous formulation of the concept of c. (Metaph., V, 2, 1013 a 24 ff.). C. is not only a principle: a principle is that which stands at the beginning of an order or a succession, whether in being, in becoming, or in knowing; c., on the other hand, is a principle of "dependence" and belongs to the real order. "Principium communius est quam causa... Principium ordinem quemdam importat; hoc vero nomen causa importat influum quemdam ad esse causati" (St. Thomas, Comm. in V Metaph., I, I, nn. 750-51). Still less is it to be confused with reason, which is what gives an explanation in the order of knowing; nor with condition, which is something extrinsic required in order for the c. to cause. As a "real" principle of being and of becoming, c. does not have a uniform meaning. Aristotle enumerated four c. of being (Physic., II, 3, 194 b 16; 195 b 30; Metaph., loc. cit., and I, 3, 983 a 26-32; IX, 4, 1044 a 32 ff.): 1) Matter, the substratum or receptive "potency" of perfections or forms; 2) form, the "act" and perfection that determines something to be what it is, that constitutes its essence or species; 3) the efficient, that "from which" the impulse to movement proceeds; 4) the end, which is the goal "for the sake of which" the efficient passes to action. The first two c. are constitutive and therefore "intrinsic" to being, while the other two are extrinsic to the effect they produce. In each group, moreover, one c. has its correspondence in the other. The c. in being are therefore not juxtaposed but interpenetrate "causally": "Nam efficiens et finis sibi correspondent invicem, quia efficiens est principium motus, finis autem terminus. Et similiter materia et forma: nam forma dat esse, materia autem recipit" (St. Thomas, loc. cit., I, II, n. 775). Other divisions, which can be common to the four c., are: c. "per se" and "per accidens", first and second, immediate and mediate, direct and indirect. Each kind of causality entails its own special subdivisions. Christian philosophy, starting especially from St. Augustine, admits as the foundation of finite reality the extrinsic formal c., or exemplary c., which are the "divine Ideas" according to which everything has been created in number, order and measure.

The doctrine of the four c. certainly constitutes the culminating point and the most characteristic aspect of Aristotelian thought. In proposing it, Aristotle was persuaded that he had reduced into a complete and coherent doctrinal body the indications that were found scattered in his predecessors (Physic., II, 3, loc. cit. and 7, 198 a 14 ff.). Some recent critics have accused Aristotle of having bent the thought of others to the purposes of his own thesis, distorting history with the double gratuitous supposition that from the beginning the problem of nature was treated as a problem of causality and that the conceptions of individual philosophers were nothing but fragments anticipating his system rather than entirely different conceptions (H. Cherniss, Aristotle's Criticism of presocratic Philosophy, Baltimore 1935, p. 218 ff.). However that may be, the theoretical value of the doctrine holds by virtue of its intimate consistency. Aristotle, drawing inspiration from the "natural philosophers" for the concept of material c., wanted to ensure the concreteness of being; then, by placing in matter "form" as the determining principle, he recognized with the Platonists the primacy of the intelligible and of spirit, on which the movement of the entire universe remains suspended, as on the first Mover and the ultimate end (Met., XIII, 9, 1074 b 34). It is not becoming, therefore, that explains being, but on the contrary it is being that explains becoming, insofar as its forms are arranged hierarchically according to the forms and degrees of causality; for this reason, in the scientific elaboration of Catholic doctrine, brought to completion in the 13th century, the Aristotelian theory was the preferred instrument, and many formulas, by now consecrated by theology and dogma, show the Aristotelian starting point and terminology.

In general, the application of the concept of c. requires the caution of analogy, both as regards the four kinds indicated and as regards their subdivisions, and this because causality directly concerns being and therefore precedes the categories (v.). Strictly speaking, causality cannot be treated as a category, but not so much or not only because the categories are classifications easily accessible in experience, as Fr. Brentano thinks (Vom d. mannigf. Bedeutung des Seins, Freiburg im Br. 1862, p. 194), while the c. are the profound and therefore less known principles, but because the c. are the very constitutive and productive principles of being and therefore precede and strictly have the character of "foundation" with respect to the "figures of the categories".

For Aristotle, as substance so also c. is first of all something individual and not universal (Physic., II, 2, 194 b 13); "Nature" therefore does not represent a causality of its own, outside and above the individual c., as Hardy wanted, but is their order and complex (v. A. Mansion, Introduction à la Physique aristotélicienne, Louvain 1913, pp. 50-51, 158; 2nd ed., ibid. 1945, pp. 59 ff., 266, n. 42). The theory of universal c. has as its repercussion the devaluation of individual c. and is proper to Neoplatonism: outlined by Plotinus with the theory of the three Hypostases (the One, Intellect, Soul), it received from Proclus the dialectical mechanism in the triadic form of unparticipated, participated, participating (E. R. Dodds, Prachus, The Elements of Theology, Oxford 1932, p. 210 ff.). Both the medievals, through the famous opuscule De causis, and Bruno's naturalistic pantheism drew inspiration from Neoplatonism, with different intentions. In rationalism c. is made to coincide with "reason"; in positivism with the simple spatio-temporal antecedent. In modern physics there is a tendency to replace c. with the concept of "probability".

II. PRINCIPLE OF CAUSALITY

The real bond and connection between the cause and the effect is called causality, and the affirmation of the necessity of such a connection is expressed by the principle of causality. The necessity of the connection can exist both on the side of the cause and on the side of the effect: in the first case there is a "necessary" cause, as opposed to a "free" cause, and it is a particular case of causality. The principle of causality, in its most universal form, expresses in general the necessity of the real dependence of every effect upon a cause. In the defense or rejection of this necessity the gravest crises of human thought have come to maturity.

Aristotle expresses the principle in terms of the fundamental fact of nature, motion: "Everything that is moved must necessarily be moved by something else" (Physic., VIII, 1, 241 b 34). The proof: "For if it does not have within itself the principle of motion, it is clear that it is moved by another; for that which moves cannot be anything other than something else" (loc. cit., 35-37). Founded upon this principle, Aristotle then proceeded to demonstrate the existence of the first unmoved Mover, God. The first form of causal skepticism is attributed in antiquity to the Pyrrhonians, among whom Aenesidemus was distinguished. Sextus Empiricus, however, attributes to the Sophists the absolute denial of causes; Aenesidemus, on the other hand, would have considered causes among those things of which one can say both that they exist and that they do not exist (Adv. Mathen., IX [adv. dogmaticos, III], § 195, 207 ff.). The negative insistence is supported first of all by the "ideal" character proper to the relation; but the cause is a relation; it therefore has a purely ideal, not real, value. A logical argument which is immediately reinforced by a more systematic one: "If the cause exists, either the body is the cause of the body, or the incorporeal of the incorporeal, or the body of the incorporeal, or the incorporeal of the body...". But none of these hypotheses is possible, as Sextus shows (loc. cit., n. 210 ff.). Sextus further reports (Hypot. Pyrrhon., I, 17, § 180 ff.) 8 "tropes" or modes with which Aenesidemus unmasked the sophisms of those who defended the existence of causes, from which one infers that the opponents in view were the Stoics, for whom the cause had always to be something material. Dialectical skepticism: Zeller (Die Philosophie der Griechen, III, II, 2nd ed., Leipzig 1868, p. 38) observes that in this critique the point that would agitate modern philosophy, the origin of the concept of cause, is not touched upon at all.

In the Middle Ages, among the Arabs, the mystical theologian al-Ghazali denies the efficacy of creatures in order to safeguard the causality of God, precluding the occasionalism of Geulincx and Malebranche. In Latin scholasticism, it was nominalism that led widely to the denial of the principle of causality, already in Ockham, followed by an ever denser array of opponents of Thomist Aristotelianism, and which had its exponent in Nicholas of Autrecourt: a skepticism predominantly logical. Nicholas affirms that from the existence of one thing (effect, creature) one cannot infer with absolute certainty the existence of another thing (the cause, God), whose denial would entail contradiction (Epist. ad Bernardum, ed. Lappe, Münster in Westf. 1908, p. 8; lin. 15 ff.). Since in the principle of causality one affirms the necessity that one thing derive from another, the predicate would come to be outside the subject ("Consequens non esset idem cum antecedente, vel cum parte significati per antecedens", loc. cit., p. 8, lin. 21). This, together with other philosophical errors connected with it, was condemned in 1346 (Denz-U, spec. 558-60).

Decisive for the development of modern thought was D. Hume's critique of causality; an epistemological skepticism, derived from the impossibility of explaining the origin of the notion of cause, in which the abandonment of causality is not so much the consequence as the ultimate foundation of universal theoretical skepticism. After having established, like the medieval skeptics, that one cannot a priori, by the examination of pure concepts (the "ideas" of cause and effect), show the necessity of the principle, Hume asks whether there is any evidence concerning their origin in the immediacy of "impressions" (of sensation or of reflection). In fact, however, experience presents only the simple succession of one phenomenon after another, never the communication of an active virtue and the necessity of a causality. Therefore the persuasion of cause lacks every foundation both a priori and a posteriori: the persistence of such a persuasion and its real utility in human conduct is a mysterious process of nature whose secret we do not know (Treatise of human Nature, p. I, sect. 14, ed. L. A. Selby-Bigge, Oxford 1928, p. 157 ff.; Appendix, p. 623 ff.). Hume's analysis of causality, solidary with associationist psychology, has been energetically rejected in our own day both by the practitioners of Gestaltpsychologie (cf. K. Koffka, Principles of Gestalt Psychology, London-New York 1936, p. 378 ff.), and by spiritualist psychologists (cf. A. Michotte, La perception de la causalité, Louvain-Paris 1946).

Kant, moved by Hume's critique, abandoned the Leibnizian rationalism of sufficient reason, in order to extend to all the principles of science, valid a priori, what Hume had said of the principle of causality (Prolegomena zu jeder künft. Metaphysik, Einleitung, pp. 260-61, akad. Ausg.). The principle of causality is presented as the "second analogy of experience" and is called "principle of production, principle of succession in time..." (Kritik der reinen Vernunft, A. 189, B. 232-33). Causality is one of the 12 categories or pure concepts of the understanding and as such a function of the transcendental "I think"; the "schema" by which it is applied to the real is the succession of the manifold insofar as it is subject to a rule (loc. cit., A. 144, B. 183). For Schopenhauer, the principle of causality becomes once again "the principle of sufficient reason of becoming" (Über d. vierfache Wurzel des Satzes vom zureichenden Grunde, c. IV, § 20, Op. O., ed. E. Griesebach, Leipzig 1891, vol. III, p. 47).

The Kantian position marked the point for further developments and for the abandonment of the classical position. A reflection of notable importance was also had in neo-Scholastic philosophy when, at the end of the last century and in the first decades of the present one, the question concerning the "analyticity" of the principle of causality was posed in explicit form. Although holding that the principle has a necessary and universal value, some energetically denied that it could be analytic (De Margerie, Vinati, Laminne, Sawicki, Hessen, Geyser...).

Although the influence of the Kantian position on this whole controversy seems undeniable, it has brought to light a real difficulty inherent in the grounding of the principle of causality, by the fact that this principle concerns the structure of objective being as such and therefore demands a pronouncement upon this objective reality. For some, in fact, the principle of causality depends on the principle of the intelligibility of the real; since this in itself is not evident and presents itself only as a "postulate" (Sawicki, Hessen), it follows that an uncaused finite reality may appear "unthinkable," but from this it does not follow that it is for that very reason "impossible" (J. Hessen, Das Kausalprinzip, Augsburg 1928, p. 227). For others, the synthetic character of the principle is inherent in causality itself insofar as it is a process; as a process it entails a development and therefore cannot be deduced a priori, and it demands accordingly to be known in an immediate apprehension, in an intuition of its essence (Wesenschau) as such (J. Geyser, Das Gesetz der Ursache, Munich 1933, p. 23). Geyser's position, which would reconcile the two currents, the analytic and the synthetic, consists of two moments: a) the direct intuition of a fact of succession, where the succession is apprehended immediately as causality and directly in the becoming and flowing of the effect from the cause, and Geyser points to inner experience (phenomenological moment); b) the further extension of the causal relation, thus apprehended, to all other cases of succession, which Geyser makes on the basis of the physical principle that "every phenomenon tends of itself to maintain itself indefinitely in its state," so that every change of the same does not come from the phenomenon itself but from something extrinsic to it (logical-metaphysical moment).

The defense of analyticity on the part of traditional philosophy has followed two paths. Although all agree in holding that the denial of causal dependence is not only unthinkable but also impossible, that is, contradictory and unreal at one and the same time, some make this contradictoriness (or "reduction ad absurdum" or "to the principle of contradiction") directly, while others do so indirectly, that is, by first reducing the principle of causality to that of sufficient reason and this latter then to the principle of contradiction (esp. R. Garrigou-Lagrange). Both groups have chosen different formulas of the principle which they consider more suited to the purposes of its critical justification, but they agree in the traditional position that the principle is absolutely valid within the sphere of being as such and that this validity of its is justifiable through its solidarity (that is, "reduction," in logical language) with the principle of contradiction. In traditional realism, logic is founded on metaphysics, so that the first principles are first of all principles of being and then consequently principles of thought. Since the principle of causality concerns the becoming and the being of the finite and the multiple, it is, by the nature of being itself, connected to the first principle of being, which is the principle of contradiction. In the terms of Aristotelian-Thomistic logic, the principle must be called "self-evident": that is to say, the requirement of the predicate is inherent in the subject, and our knowledge of the predicate derives of necessity from the knowledge of the subject. This derivation can be twofold: either of the first degree ("propositio per se nota primo modo"), as happens for all strictly essential elements of a definition; or of the second degree, when it is a matter of properties that concern or derive directly and necessarily from the essence. According to St. Thomas, the principle of causality falls into the second category: "Licet habitudo ad causam non intret definitionem entis quod est causatum, tamen sequitur ad ea quae sunt de eius ratione; quia ex hoc quod aliquid per participationem est ens, sequitur quod sit causatum ab alio. Unde huiusmodi ens non potest esse quin sit causatum; sicut nec homo, quin sit risibilis. Sed quia esse causatum non est de ratione entis simpliciter, propter hoc invenitur aliquod ens non causatum" (Sum. Theol., 1ᵃ, q. 44, a. 1 ad 1).

The formula of participation thus constitutes in Thomistic metaphysics the definitive expression of causal dependence. It expresses the ultimate relationship between God and the creature, between substance and accident... that is, the dependence of being, in the expression of maximum conceptual purity (the notion of participation), in which dependence, likeness and distinction converge at one and the same time, all characteristics proper to the effect with respect to its cause, and which no other notion is capable of expressing in this way. In the Thomistic position, then, the complicated controversy in which a great part of Neo-Scholasticism has been embroiled, and not always with the best results, has no reason to exist, but finds its explanation in having chosen, for the critical defense of the principle of causality, various formulas more or less unsuited to the strictly critical-metaphysical requirement of the defense.

The definitive critical formula of the principle of causality must: a) embrace everything that is in some way caused; b) express immediately the dependence of the effect on the cause.

Among the formulas that have enjoyed the greatest vogue in the discussion (there is no need to mention: "omnis effectus habet causam," because if "effectus" means that which is caused, it is of itself useless to the discussion, and if it does not mean this, it must rest on other concepts), the most important are the following: 1) Omne quod movetur ab alio movetur. A strictly Aristotelian formula (Phys., VII, 1, 241 b 34), and placed by St. Thomas at the foundation of the first way for demonstrating the existence of God (Sum. Theol., 1ᵃ, q. 2, a. 3), but for that very reason limited to a precise sector of causality, that of motion. 2) Omne quod incipit exigit causam. This is the formula preferred by Hume, but it is also found in St. Thomas, who, however, as is well known, did not regard beginning to be and being created as such as inseparable, and admitted the possibility of a creation "ab aeterno." It therefore cannot represent the definitive formula. 3) Omne quod est in potentia non fit (actu) nisi per aliquod ens actu. An Aristotelian formula (cf. Met., IX, 8, 1049 b 24) which provides the metaphysical foundation of the two preceding ones and which rests on the two cornerstones of the philosopher's metaphysics, but that he understood only in function of natural becoming, without arriving at the first origin of beings from God, and of pure potency (prime matter) from pure Act (God). 4) Omne contingens (quidquid contingenter existit) habet causam. This is the formula that has enjoyed the greatest favor among the Neo-Scholastics (Garrigou-Lagrange, Droege, Boyer, Descoqs) and that is certainly not foreign to Thomism, given that for Aristotle too being is divided into contingent and necessary (cf. Met., V, 5, 1015 a 20 ff.). "Contingens" corresponds to the "possibile esse" which St. Thomas uses in the third way, but in Thomist metaphysics this "contingent" coincides with material reality subject to generation and corruption and therefore cannot take the place of caused being as such. For the Angelic Doctor, who in metaphysics takes up a terminology that Aristotle uses in logic (for conclusions derived from necessary premises, Met., V, c. 1015 b 9-11), there are necessary things that have a cause of their necessity, that is, which are caused "ab alio," which is necessary by essence (cf. C. Gent., II, 30: Qualiter in rebus creatis possit esse necessitas absoluta; C. Fabro, Intorno alla nozione tomista di contingenza, in Riv. di filos. neosc., 30 [1938], p. 132 ff.). 5) Omne compositum, indiget causa componente. This formula truly embraces every created being and is frequently found in St. Thomas (cf. the full enunciation in: Sum. Theol., 1ᵃ, q. 3, a. 4). In its ultimate metaphysical scope it points back to the first composition of finite being, that of essence and act of being, in which the condition and the first effect of creation itself are manifested. And creation is held by St. Thomas to be demonstrable and is demonstrated by him with the principle of participation (Sum. Theol., 1ᵃ, q. 44, a. 1), just as with the same principle the Angelic Doctor demonstrates the real distinction of essence and act of being (Quodlib., II, q. 2, a. 3). Of the two moments of participation, as causal dependence and real composition, it seems to us that in our process of critical-metaphysical justification of the principle of causality, participation as causality comes first, and then, in dependence on this, the further determination of the creature as a reality of composition. Such is the constant method followed by St. Thomas (cf. C. Fabro, La nozione metafisica di partecipazione..., Milan 1941, p. 216 ff.), and it is the only one that goes to the root of the problem. The notion of participation, by its metaphysical purity, was suited together with all the nuances of analogy (v.) to which the notion of cause is subject, both in the fourfold division of causes and in the distinction between infinite causality (secundum esse, proper to God) and the multiple actuations of finite causality (secundum fieri, proper to finite agents).

It may be added that in his notion of participation St. Thomas saw converging the element of perennial truth of Platonism and Aristotelianism (cf. De subst. sep., c. 3) and that in it the very basic conception of Aristotelian metaphysics, that of act and potency, finds that definitive resolution which allows one to escape both dualism (of absolute separation) and acausalism (God, only as final cause, not productive of the world), of which the Aristotelian theory has been repeatedly accused, from the Fathers down to our own day. Moreover, the notion of participation does not seem alien to permitting certain opportune insertions of Christian thought in order to satisfy what may be the legitimate demands of modern thought for conceiving the structure of the subjectivity of spiritual being and the dependence of the finite on the infinite; provided that this be done with the cautions used by the Angelic Doctor, avoiding the excesses of some of his disciples (Eckhart, Theodoric of Freiberg). On this notion is founded the fourth way, which is generally held to be the most important for the demonstration of the existence of God, which, as St. Thomas says in the Prologue to the Lectura in Ioannem (ed. Parm., t. X, 280 a), is proper to the Platonists "qui venerunt in cognitionem Dei ex dignitate ipsius Dei."

The formula of participation therefore appears the most apt to satisfy the conditions of universality and immediacy that the critical formulation of the principle requires.

Cornelio Fabro