Cause

CAUSE. –

I. NOTION

According to the most reliable etymology, the first scientific application of the concept of c. would have occurred 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 the principle and constituent of the reality of being. According to Tannery (A. Lalande, Vocab. crit. de la philos., I, p. 100, note), whereas the Greeks emphasized the initial juridical moment of “inquiry” and accusation (αἰτειν, αἰτία, αἰτῶν), the Latins insisted on that of “defense” (canere, causa), from which there also derived the Neo-Latin terms connected with the Italian “cosa.” An existential insight also noted by G. Marcel: “Would imputability, or rather the need to impute (to have something or someone with whom to enter into dispute), not in fact lie at the origin of every causal explanation?” (Être et Avoir, Paris 1935, p. 8).

It is to Aristotle, who was well acquainted with 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 merely principle: principle is that which stands at the beginning of an order or succession, whether in being, becoming, or knowing; c., on the other hand, is the principle of “dependence” and belongs properly 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, nos. 750-51). Still less is it to be confused with reason, which is that which provides an explanation in the order of knowing; nor with condition, which is something extrinsic required in order that c. may cause. As the “real” principle of being and 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 “potentiality” of perfections or forms; 2) form, the “act” and perfection that determines something to be what it is and constitutes its essence or species; 3) the efficient cause, that “from which” the impulse toward movement proceeds; 4) the end, which is the purpose “for the sake of which” the efficient cause passes into action. The first two c. are constitutive and therefore “intrinsic” to being, whereas the other two are extrinsic to the effect they produce. Within each group, moreover, one c. corresponds to the other. 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, no. 775). Other divisions, which may 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, especially from St. Augustine onward, admits as the foundation of finite reality the extrinsic formal cause, or exemplary cause, namely 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 convinced that he had reduced to a complete and coherent doctrinal body the indications scattered among his predecessors (Physic., II, 3, loc. cit., and 7, 198 a 14 ff.). Some recent critics have accused Aristotle of bending the thought of others to the purposes of his own thesis, distorting history through the two gratuitous assumptions that, from the beginning, the problem of nature had been treated as a problem of causality, and that the conceptions of individual philosophers were merely fragments anticipating his system rather than wholly different conceptions (H. Cherniss, Aristotle's Criticism of presocratic Philosophy, Baltimore 1935, p. 218 ff.). Whatever the truth of the matter, the theoretical value of the doctrine rests on its inner consistency. Aristotle, taking inspiration from the “natural philosophers” for the concept of material c., sought to secure the concreteness of being; then, by positing “form” within matter as its determining principle, he acknowledged with the Platonists the primacy of the intelligible and of spirit, upon which, as upon the first Mover and the final end, the movement of the entire universe depends (Met., XIII, 9, 1074 b 34). It is not becoming, therefore, that explains being; rather, being explains becoming, insofar as its forms are hierarchically ordered according to the forms and degrees of causality. For this reason, in the scientific elaboration of Catholic doctrine, brought to completion in the thirteenth century, Aristotelian theory became the preferred instrument, and many formulas, by now consecrated by theology and dogma, display Aristotelian inspiration and terminology.

In general, the application of the concept of c. requires the caution of analogy, both with regard to the four indicated kinds and with regard to their subdivisions, 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 categories are classifications readily accessible in experience, as Fr. Brentano thinks (Vom d. mannigf. Bedeutung des Seins, Freiburg im Br. 1862, p. 194), whereas c. are the profound and therefore less familiar principles; rather, it is because c. are the very constitutive and productive principles of being and therefore precede the “figures of the categories” and, strictly speaking, have the character of “foundation” in relation to them.

For Aristotle, just as substance is, so c. is first and foremost something individual and not universal (Physic., II, 2, 194 b 13); “Nature,” therefore, does not represent a causality in itself, outside and above the individual c., as Hardy maintained, but is their order and totality (v. A. Mansion, Introduction à la Physique aristotélicienne, Louvain 1913, pp. 50-51, 158; 2nd ed., there 1945, pp. 59 ff., 266, n. 42). The theory of universal c. has as its counterpart the devaluation of individual c. and is characteristic of Neoplatonism: outlined by Plotinus with the theory of the three Hypostases (One, Intellect, Soul), it received from Proclus its dialectical mechanism in the triadic form of unparticipated, participated, and participating (E. R. Dodds, Prachus, The Elements of Theology, Oxford 1932, p. 210 ff.). Neoplatonism inspired, with differing aims, both the medieval thinkers, through the celebrated little work De causis, and Brunian naturalistic pantheism. In rationalism, c. is identified with “reason”; in positivism, with the mere spatiotemporal 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 this connection is expressed by the principle of causality. The necessity of the connection may exist either on the part of the cause or on the part of the effect: in the first case there is a “necessary” cause, as opposed to a “free” cause, and this 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. The gravest crises in human thought have arisen in the defense or rejection of this necessity.

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 but something else” (loc. cit., 35-37). On the basis of 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, is said to have regarded causes among those things of which it may equally be said that they exist or that they do not exist (Adv. Mathen., IX [adv. dogmaticos, III], § 195, 207 ff.). The negative position is based above all on the “ideal” character proper to relation; but a cause is a relation and therefore has a purely ideal, not a real, value. This logical argument is immediately reinforced by a more systematic one: “If the cause exists, either body is the cause of body, or the incorporeal of the incorporeal, or body of the incorporeal, or the incorporeal of body....” But none of these hypotheses is possible, as Sextus shows (loc. cit., no. 210 ff.). Sextus also reports (Hypot. Pyrrhon., I, 17, § 180 ff.) eight “tropes,” or methods by which Aenesidemus exposed the sophisms of those who defended the existence of causes; from this it may be inferred that the opponents at issue were the Stoics, for whom a cause always had to be something material. Dialectical skepticism: Zeller (Die Philosophie der Griechen, III, II, 2nd ed., Leipzig 1868, p. 38) observes that this criticism does not touch at all upon the issue that would agitate modern philosophy, namely, the origin of the concept of cause.

In the Middle Ages, among the Arabs, the mystical theologian al-Gazzàli denied the efficacy of creatures in order to safeguard the causality of God, thereby paving the way for the occasionalism of Geulincx and Malebranche. In Latin Scholasticism, it was nominalism that led broadly to the denial of the principle of causality, beginning with Ockham, followed by an increasingly numerous group of opponents of Thomistic Aristotelianism, whose representative was Niccolò di Autrecourt: skepticism predominantly logical in character. Niccolò asserts that from the existence of one thing (the effect, the creature) one cannot infer with absolute certainty the existence of another thing (the cause, God), the denial of which would entail a contradiction (Epist. ad Bernardum, ed. Lappe, Münster in Westphalia 1908, p. 8; lines 15 ff.). Since the principle of causality affirms the necessity that one thing derive from another, the predicate would come to lie outside the subject (“Consequens non esset idem cum antecedente, vel cum parte significati per antecedens,” loc. cit., p. 8, line 21). This, together with other philosophical errors connected with it, was condemned in 1346 (Denz-U, esp. 558-60).

Decisive for the development of modern thought was D. Hume’s critique of causality: epistemological skepticism, arising 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. Having established, like the medieval skeptics, that one cannot, a priori, by examining pure concepts (the “ideas” of cause and effect), demonstrate the necessity of the principle, Hume asks whether there is any evidence of their origin in the immediacy of “impressions” (of sensation or reflection). In fact, however, experience presents only the simple succession of one phenomenon after another, never the communication of an active power and the necessity of a causal relation. Thus the belief in causality lacks every foundation, both a priori and a posteriori: the persistence of this belief and its real usefulness in human conduct are a mysterious process of nature whose secret we do not know (Treatise of human Nature, p. I, sect. 14th, ed. L. A. Selby-Bigge, Oxford 1928, p. 157 ff.; Appendix, p. 623 ff.). Hume’s analysis of causality, bound up with associationist psychology, has in our own day been forcefully rejected both by adherents 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 the “principle of production, the principle of succession in time...” (Kritik der reinen Vernunft, A. 189, B. 232-33). Causality is one of the twelve 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 reality 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 once again becomes “the principle of sufficient reason of becoming” (Über d. uerfache 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 turning point for subsequent developments and for the abandonment of the classical position. It also had a significant effect on neo-Scholastic philosophy when, at the end of the last century and during the first decades of the present one, the question of the “analyticity” of the principle of causality was explicitly raised. While maintaining that the principle possesses necessary and universal validity, some vigorously denied that it could be analytic (De Margerie, Vinati, Laminne, Sawicki, Hessen, Geyser...).

Although the influence of the Kantian position throughout this controversy seems undeniable, it has brought to light a real difficulty inherent in the foundation of the principle of c., since this principle concerns the structure of objective being as such and therefore requires a pronouncement regarding this objective reality. For some, in fact, the principle of c. depends upon the principle of the intelligibility of the real; since the latter is not self-evident in itself and presents itself only as a “postulate” (Sawicki, Hessen), it follows that an uncaused finite reality may seem “unthinkable,” but it does not follow from this that it is thereby “impossible” (J. Hessen, Das Kausalprinzip, Augsburg 1928, p. 227). For others, the synthetic character of the principle is inherent in causality itself insofar as causality is a process; as a process, it entails a development and therefore cannot be deduced a priori, but must consequently 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 seeks to reconcile the analytical and synthetic currents, consists of two moments: a) the direct intuition of a fact of succession, in which succession is immediately apprehended as causality and directly in the becoming and flowing of the effect from the c.; Geyser identifies internal experience with this (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 in itself to remain indefinitely in its state,” so that any alteration of it does not proceed from the phenomenon itself but from something extrinsic to it (logical-metaphysical moment).

The traditional philosophy’s defense of the analytical character has followed two paths. Although all agree in holding that the denial of causal dependence is not only unthinkable but also impossible—that is, at once contradictory and unreal—some establish this contradictoriness directly, while others do so indirectly, first reducing the principle of c. to that of sufficient reason and then reducing the latter to the principle of contradiction (especially R. Garrigou-Lagrange). Both groups have chosen different formulations of the principle, which they consider more suitable to the purposes of its critical justification, but they agree with the traditional position that the principle is absolutely valid within the sphere of being as such and that this validity can be justified by its solidarity (that is, “reduction,” in logical terminology) with the principle of contradiction. In traditional realism, logic is founded upon metaphysics, so that first principles are above all principles of being and only consequently principles of thought. Since the principle of c. concerns becoming and the being of the finite and the multiple, it is, by the very nature of being itself, connected with the first principle of being, namely, the principle of contradiction. In Aristotelian-Thomistic logical terms, the principle must be called “per se known”: that is to say, the requirement of the predicate is inherent in the subject, and our knowledge of the predicate necessarily derives from our knowledge of the subject. This derivation may be of two kinds: either of the first degree (“propositio per se nota primo modo”), as occurs with all the strictly essential elements of a definition; or of the second degree, when it concerns properties that bear directly and necessarily upon the essence or derive from II. According to St. Thomas, the principle of causality belongs to 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 therefore constitutes, in Thomistic metaphysics, the definitive expression of causal dependence. It expresses the ultimate relationship between God and the creature, between substance and accident—in other words, the dependence of being—in the expression of the greatest conceptual purity (the notion of participation), in which dependence, likeness, and distinction coincide, all characteristics proper to the effect in relation to its c., and which no other notion is capable of expressing in this way. From the Thomistic standpoint, therefore, the complicated controversy in which a large part of neo-Scholasticism has been engaged, and not always with the best results, has no reason for existing; its explanation lies in the fact that, for the critical defense of the principle of c., formulas more or less unsuited to the strictly critical-metaphysical requirements of that defense were chosen.

The definitive critical formulation of the principle of c. must: a) embrace everything that is in some way caused; b) immediately express the dependence of the effect upon the c.

Among the formulas that have enjoyed the greatest currency in the discussion (there is no need to mention “omnis effectus habet causam,” because if “effectus” says what is caused, it is useless for the discussion as such, while if it does not say this, it must rely upon 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), placed by St. Thomas at the foundation of the first way of demonstrating the existence of God (Sum. Theol., 1ᵃ, q. 2, a. 3), but for that very reason limited to a specific sector of causality, namely, motion. 2) Omne quod incipit exigit causam. This is the formula preferred by Hume, but it is also found in St. Thomas, who, as is well known, did not regard coming into being and being created as such as necessarily connected, 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) that provides the metaphysical foundation of the two preceding formulas and rests upon the two cornerstones of the philosopher’s metaphysics, but

which he understood solely in relation to natural becoming, without reaching the first origin of beings from God, and of pure potency (prime matter) from the Pure Act (God). 4) Omne contingens (quidquid contingenter existit) habet causam. This is the formula that has found 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» used by St. Thomas in the third way, but in Thomistic 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 takes up in metaphysics a terminology that Aristotle uses in logic (for conclusions derived from necessary premises, Met., V, c. 1015 b 9-11), there are things that are necessary and have a cause of their necessity, that is, 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 formulation in: Sum. Theol., 1ᵃ, q. 3, a. 4). In its ultimate metaphysical import it refers to the first composition of finite being, that of essence and the act of being, in which the condition and the primary effect of creation itself are manifested. And creation is held by St. Thomas to be demonstrable, and is demonstrated by him through the principle of participation (Sum. Theol., 1ᵃ, q. 44, a. 1), just as by the same principle the Angelic Doctor demonstrates the real distinction between essence and the 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 c., participation as causality comes first, followed by the further determination of the creature as a reality of composition, which depends upon II. 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 reaches the root of the problem. The notion of participation, by virtue of its metaphysical purity, was at the same time suited analogy (v.) to which the notion of c. is subject, both in the fourfold division of causes and in the distinction between infinite causality (secundum esse, proper to God) and the multiple actualizations 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 in Platonism and Aristotelianism (cf. De subst. sep., c. 3), and that in it Aristotle’s own basic conception of metaphysics, that of act and potency, finds the definitive resolution that makes it possible to escape both dualism (of absolute separation) and acausalism (God as merely final cause, not productive of the world), of which Aristotelian theory has repeatedly been accused, from the Fathers to the present day. Moreover, the notion of participation does not seem incapable of allowing certain appropriate insertions of Christian thought, so as to meet those legitimate demands of modern thought that may arise in conceiving the structure of the subjectivity of spiritual being and

the dependence of the finite on the infinite, provided that this is done with the precautions employed by the Angelic Doctor, avoiding the overstepping found in some of his disciples (Eckhart, Teodorico di Friburgo). The fourth way, which is generally regarded as the most important for demonstrating the existence of God, is founded upon this notion; as St. Thomas says in the Prologue to the Lectura in Ioannem (ed. Parm., t. X, 280 a), it is proper to the Platonists « qui venerunt in cognitionem Dei ex dignitate ipsius Dei ».

The formula of participation therefore appears the best suited to satisfy the conditions of universality and immediacy demanded by the critical formulation of the principle.