CAUSALITY

In a general sense causality designates anything that has the character of a cause; more specifically it describes the relationship between cause and effect. Sometimes it is distinguished from causation, which is taken to mean any type of causative action (see action and passion). Cause (Gr. αἰτια, αἵτιον; Lat. causa ) is itself defined by scholastics as, that from which something else proceeds with a dependence in being. It is related to principle, which is that from which something proceeds in any way whatsoever; to condition, which is a prerequisite factor needed to make causal action effective; and to occasion, which is an opportunity that may induce a free agent to act.

This article first exposes Greek and scholastic teaching on causality, furnishing a brief historical survey of its development to medieval times, together with an analysis of the nature of causality and the corollaries it entails. It then recounts and criticizes views on causality held by some of the principal philosophers of the modern and contemporary periods.

Greek and Scholastic Teaching

The origins of causality in Greek thought are summarized in various works of aristotle (esp. Meta. 983a 25–984b 20). Aristotle notes that while none of the previous philosophers had furnished a systematic exposition of causality, their separate and sometimes confused treatments give evidence of four different types of causes.

CLASSIFICATION AND HISTORY

The four causes enumerated by Aristotle are "the matter, the form, the mover, and 'that for the sake of which'" (Phys. 198a 20–25). These have became known as the material, formal, efficient and final causes.

Basic definitions. By matter or material cause Aristotle means "that out of which a thing comes to be and which persists." Examples would be the cloth out of which a suit is made and the tobacco of a cigar. By form or formal cause he refers to "the form or archetype, that is, the statement of the essence." In art, the shape of a bowl would constitute its formal cause; in nature, the soul of a living thing would be its formal cause. By mover, agent, or efficient cause Aristotle understands the "primary source of the change or coming to rest" (see efficient causality). Thus a carpenter is the efficient cause of a house's being built, or wind is the cause of the motion of waves on water. By final cause, he means that "in the sense of end or that for the sake of which a thing is done" (see final causality). For example, one studies in order to become learned, or the natural camouflage of animals is for the sake of protecting them from their enemies. Final cause may also refer to the object of desire or the desire of the object. (Confer, Phys. 194b 20–35.)

Pre-Socratics. The earliest of the causes, sought by the pre-Socratics although not formally recognized as such, was the material cause. All the Ionians searched for one or more types of matter composing the cosmos, some opting for water (Thales), others for air (Anaximenes) or an indeterminate apeiron (Anaximander). Later philosophers enquired into the material and the efficient causes of things. empedocles, for example, posited friendship and strife as the forces uniting or dissolving the combination of the elements, thus accounting for order and chaos respectively. Such forces can be interpreted along the lines of efficient causality. anaxagoras also apparently hinted at efficient causality in his doctrine of Nous, although, as Aristotle observed, this offered more promise that it gave (see greek philosophy).

Socrates and Plato. socrates may be said to have searched for the final causes of human conduct in his quest for the virtuous life. The Pythagoreans and especially plato, made further advance into the quest for causes by investigating formal causality. For Plato, these forms or archetypes in the world of ideas are the patterns participated and imitated by sensible reality. Analogously, as a shadow has its meager reality from the tree that casts it and the sun that makes this possible, so the sensory world has its reality by virtue of the ideas (forms) it imitates and the One above the ideas. This theme of participation runs throughout many of Plato's middle and later works. Plato also makes use of efficient causality when he speaks of the demiurge (confer, Timaeus ) as forming the world below.

Aristotelian and other usage. Aristotle not only presented a thorough enumeration and description of the various causes, but went on to employ them extensively in his works. He viewed all science (scientia) as a search for causes, for only causal knowledge is scientific knowledge. His theory of proof or demonstration (confer, Posterior Analytics ) is rooted in this doctrine of causes. The connecting link between a subject (S -term) and its attribute (P -term) is a cause (M -term). Thus the cause (M -term) always tells why P belongs to S or how one knows that P belongs to S. Hence, all science is "a search for the middle term." Both in the Physics and in the Metaphysics, Aristotle comes to the conclusion of the existence of an Unmoved Mover or an Uncaused Cause. The Uncaused Cause is commonly viewed as an object of desire and thus as a final cause, while the Unmoved Mover is often interpreted as an efficient cause. To sum up the importance of Aristotle's contribution on the subject of causality, this lay in his showing to others what to look for when seeking scientific knowledge and how to proceed in such investigation. His systematic treatment and delineation of the causes changed the search for truth from a random groping to a systematic enquiry.

Later Greek thought. After Aristotle, there was comparatively little stress on formal recognition and use of causes. Skeptics rejected them and the Stoics were primarily interested in the ethical life of virtue amidst a pantheistic setting. The latter did, however, stress the immanent causality of the logos in the world and of "seeds" in things as active forms from which reality emerges. The Epicureans accepted atomism with its consequent denial of teleology or final causality. Neoplatonists were principally noted for their attempt to merge Aristotelian and Platonic teachings on causality. They gave further impetus to recognition of a fifth cause, the exemplary cause (see exemplary causality).

Scholastic development. Although Aristotle laid the essential groundwork for the doctrine of causality, it was mainly the scholastics who further clarified, refined and applied his doctrine. Nearly all employed the Aristotelian terms, but many offered various interpretations and applications of the doctrine.

Since the most notable Aristotelian in the medieval Latin West was St. thomas aquinas, his views will be summarized here. St. Thomas defines cause in a number of ways, but two of his definitions contain the essential elements. A cause is "that upon which something else follows of necessity" (In 5 meta. 1.749). Again, a cause is that which "brings some influence on the being of the thing caused" (ibid. 751). The key to understanding causality, for Aquinas, is to see that it always involves a positive principle exerting some influence on a perfection or thing that is coming to be, that is, an influx into being. His definitions are necessarily obscure, for the notion of causality is fundamentally analogical and no analogical term admits of a strict definition (see analogy). One error of present-day thinkers in appraising causality is to ignore this analogical character of the causes and attempt to reduce all causality to some type of efficient cause. This preoccupation leads automatically to mechanism.

JUSTIFICATION OF CAUSALITY

Virtually no philosopher has denied the practical utility and necessity of the concept of causality, although frequent efforts have been directed toward showing that, in the real order, this concept is speculatively unverifiable. Yet man can and does regularly verify the extramental existence of causal influences. His starting point, most evident in experience, is the fact of change. He observes change in nature and experiences himself as capable of producing it. Explanation of the obvious fact of change and motion thus leads to explicit knowledge of the doctrine of causes.

In the most commonplace examples of change, for example, the sculpting of a statue, an agent (efficient cause) does something to a marble subject (material cause). As a result of the agent's activity, the marble comes to possess actually a new shape or determination (formal cause). What prompted this action on the part of the agent was the fact that he sought to produce something: he had some goal at which he aimed (final cause). Briefly, then, in changes produced by art, one observes that there must be a substratum (material cause), a determination (formal cause) that comes to be actually present in the substratum through the activity of an agent (efficient cause), for some purpose (final cause).

Making an analogous transition from art to the order of nature, one sees that the material cause accounts for the continuity that is evident in all changes in the universe; the formal cause is the principle of novelty, without which no change would be manifest; the efficient cause initiates and makes this novelty to come about actually; and the final cause accounts for the action's tending to a determinate effect. The principles involved in this explanation apply then, not merely to art, but to nature and to physical change as such. Consequently and in analogous fashion, one can understand that such causes are also required for any change in the physical world, whether these be substantial or accidental.

St. Thomas summarizes this line of reasoning as follows:

There must of necessity be four causes: because when a cause exists, upon which the being of another thing follows, the being of that which has the cause may be considered in two ways. First, absolutely; and in this way the cause of being is a form by which something is a being-in-act …. It follows of necessity that there are two other causes, namely the matter and the agent that reduces the matter from potency to act. But the action of an agent tends to something determinate, just as it proceeds from some determinate principle, for every agent does what is in conformity with its nature. That to which the action of the agent tends is called the final cause. Thus, there are necessarily four causes. [In 2 phys. 10.15.]

Since change is an objective occurrence in the real order, the principles without which it would be unintelligible are clearly objective as well; hence the foregoing explanation is not to be construed as psychological, but as ontological in character. It requires, moreover, an intellectual insight into the nature of real beings and their operations. Hence, nominalists and empiricists, denying the intellect's ability to grasp natures, also reject this explanation. The exposition above is predicated on the indemonstrable first principle that being is intelligible and accordingly, that man can know (in the sense of understand) reality itself (see first principles).

ANALYSIS OF CAUSALITY

Because the rejection of scholastic views on causality by modern philosophers is based largely on a misunderstanding of what is meant by causality and how it occurs, some refinements of the explanation already given are now attempted.

One or more effects. In a certain sense, the effect of the various causes is but one effect of all four—each contributing to this effect in its own special manner. Yet the following distinctions obtain. Material and formal causes may be regarded as intrinsic, for they enter into the composition of the thing. Efficient and final causes are said to be extrinsic. The material cause influences the being of the effect through its role as subject, recipient and passive principle, thereby limiting the act that it receives. The formal cause has for its effect the determination or specification of the being of the effect, thereby making it to be this kind of thing rather than that. The efficient cause has for its effect the coming-to-be of the new determination (form) in the subject. Lastly, the final cause has for its effect the perfection itself that has come to be, formally considered as a term of the intention of the agent. It should be noted that this intention need not be conscious or cognitive in the agent; it can be simply a tendency of the agent.

Reciprocity of causes. Reciprocity is often evident between causes. The final cause explains why the agent causes, while the agent makes the final cause or end come to be. When the final cause is considered in the order of intention, it is what moves the agent to act. When it is considered in the order of execution, it is what the agent has produced. Thus, as Aristotle observes, health is the final cause of walking, but walking in turn produces or contributes to health. Hence, the final cause may be termed first in the order of intention and last in the order of execution. It is also termed the highest of the causes for without it none of the other causes could actually cause.

Nature of causal action. No agent loses anything in causing. To cause is itself a perfection; for an agent to necessarily lose in causing would be for it to become increasingly less perfect and this implies a contradiction. It must be noted, therefore, that there is no transfer in causing as such—a position St. Thomas calls ridiculum (C. gent. 3.69)—as though the agent causes by "giving up" its own form or perfection, thereby entailing its loss. Leibniz apparently misunderstood the scholastic doctrine in this manner.

Instead, causing by finite beings involves an eduction of the form from the potency of the matter (see matter and form). Strictly, the form does not come from the agent. Rather, by means of the action of the agent, the form that was already potentially in the matter comes to be present there actually. Thus water in becoming warm does not literally receive heat from the fire. It is because the flame is actually hot that water, which is potentially hot, comes to be actually so.

It is nonetheless true to say that finite causes lose in causing, although this is not because they are causing as such. Their loss is due to the presence of other causes acting reciprocally upon them. Since in the physical order every action involves a reaction, it is impossible to separate physically the activity of an agent from its being acted upon by a reciprocal agent. A physical agent, when acting, is always a patient with respect to something else. What is required to understand causality, therefore, is an intellectual abstraction whereby one considers separately two distinct but inseparable elements as these occur in the physical order.

Priority of nature. The priority of the cause to the effect, considering both in the order of act, is not a priority of time but one of nature. The effect flows from the cause and not conversely. Although parents, as human beings, exist temporally before their offspring, they do not do so strictly qua parents. They become parents only at the moment of conception. In the order of act, therefore, a cause and its proper effect are simultaneous. For this reason the effect continues to be only so long as its cause(s) continue to act. It is important to distinguish, therefore, the proper effect of a cause from its general effect. One can say that a tailor is the cause of the suit, as his general effect, but not that the suit is the proper effect of the tailor, for obviously the suit can continue to be when the tailor has died. Rather the proper effect of the tailor is the suit in its coming-to-be. Thus, the suit begins to become, continues becoming and ceases to become only so long as the tailor begins, continues and stops working on it. The suit continues to be, therefore, not because of the tailor—who no longer exerts causal influence with respect to it—but because its material and formal causes effect this conjointly.

Action and passion. With respect to efficient causality, there is only one motion or action, but this gives rise to two categories of being: passion, from the viewpoint of the patient; and action, from the viewpoint of the agent. There is then but one actuation and the change as such is in the patient, not in the agent. This can be more easily stated by saying that the effect is a prolongation of the act of the agent in the patient. There are not two separate acts that somehow must be connected by a third, essentially the mistaken view of Hume; there is but a single act.

Causes of being and becoming. The distinction between a cause in the order of becoming (in fieri ) and a cause in the order of being (in esse ) must also be noted. A creature's causality is limited to the order of becoming, while only God can cause in the order of being. The limitation of a creature's causality is shown by the fact that existence (esse ) proceeds from the form and no creature is a total cause of any form. Rather, creatures are causes of a form's eduction from the potentiality of matter. If creatures do not cause the form as such, much less are they causes of the esse resulting from the form. God's unique causality in the order of being is also clear from the fact that only what is esse can cause it. Since creatures merely have esse, they cannot cause it in the strict sense.

From these notions a number of corollaries follow. One is that nothing can escape the universal causality of God. Since becoming proceeds from being as its principle and tends toward being as its term, becoming always presupposes causality in the order of being. Another corollary is that the causality of any creature presupposes the concurrent causality of God (see concurrence, divine). This should not be viewed as prohibiting genuine secondary causality by creatures, as proposed by occasionalism. Rather it is the very thing that makes creatures capable of exercising their own causality (see causality, divine).

Subdivisions of causes. Among the many distinctions that can be employed to render causality intelligible are those that subdivide the various causes. Thus, material cause may refer to primary matter or secondary matter in physical things, depending on whether one is concerned with substantial or accidental change. Formal cause may be subdivided into substantial formal cause, that is, the soul of an animate being, or accidental formal cause, that is, quantity or various qualities. Efficient cause may be divided in many ways. The most important of these would be the divisions into primary and secondary; principal and instrumental; necessary and free; ultimate, intermediate and proximate; and total and partial. The final cause may be viewed as either the object of desire or the desire of the object, the end of generation or the end of the generated thing, etc. A fifth cause, of which Aquinas makes fruitful use, is the exemplary formal cause. Briefly, it is "a form, in imitation of which something comes into being from the intention of an agent that determines its end for itself" (De ver. 3.1). This is like a blueprint in the mind of an artificer, according to which some artifact is fashioned.

Causality in Modern Thought

Entering the era of modern philosophy, one experiences a consensus that is definitely antithetic to the traditional doctrine of causality. In what follows, the principal teachings of philosophers who have been most influential in this area, namely, empiricists, rationalists, and positivists, will be sketched.

BACON AND DESCARTES

Francis bacon is representative of this movement in its early stages. He appears to be interested primarily in formal causes, although these for him often serve as nothing more than laws of nature. However, at times his formal causes bear a resemblance to efficient causes. He removes final causality from the realm of natural philosophy and bequeathes it to metaphysics. For all practical purposes, he seems to have regarded final causes as an anthropomorphism that had best be purged from the field of science.

René descartes added further impetus to this general opposition to traditional causes. In making matter inert and in reducing all motion to local motion, he prepared the way for mechanism. The Cartesian view does not admit that things have intelligibility or necessity in their own right, because, as J. Maritain has rightly observed, Descartes made things depend for their intelligibility upon a divine will and not upon divine ideas. Hence, for him, final causes lead to a fruitless search and can be dismissed from human enquiry.

LOCKE AND HUME

John locke and David hume were both empiricists and nominalists, Hume being the more consistent of the two. Their rejection of causality could easily have been anticipated. However, in Locke's case, rather than reject causality outright, he preferred to relegate it, as he did substance, to the realm of the unknowable. For both Locke and Hume, all that man can know are successive phenomena.

It is primarily by Hume that the major attack is launched upon efficient causality. According to Hume, man knows only his ideas and images directly and not the world of reality. Mind is, for him, simply a state of successive phenomenal impressions and judgment is replaced by association. In asking whether causality can be justified, Hume requests that one show how its most important characteristic, necessary nexus, is grounded in experience. Not finding it rooted there, he concludes that the necessary connection between cause and effect is psychological, having its ground in custom and the association of ideas. Cause thereupon becomes a relationship among ideas and no longer an influence of one thing upon the other in the real world. However, Hume never berated the practical utility of the notion of cause; he simply maintained its speculative unverifiability. Again, for Hume, instinct is more to be trusted than reason.

The principal shortcoming of Hume's view stems from his empiricism and nominalism. He attempted to have the senses detect, in a formal way, causality and necessity per se—something that those powers are incapable of doing. Aquinas had himself observed that not even substance is sensible per se, but only per accidens. Since he did not admit abstraction of an intellectual nature, Hume was consistent within his own system in rejecting causality and substance. And, unable to justify causality ontologically, he did the next best thing in justifying it psychologically. Yet Thomas reid, of the "Common Sense" school of philosophy, disagreed violently with Hume's conclusions and reacted by making causality a first principle of knowledge.

KANT'S CRITIQUE

Immanuel Kant, awakened by Hume from the "dogmatic slumber" of Wolffian rationalism, saw Hume's problem but was not content to accept his solution. For Kant, Hume's was no solution and so he himself faced the thorny problem of justifying causality. Kant's faith in Newtonian physics and mathematics required him to find an answer that would preserve the status of those disciplines. He felt no such concern for metaphysics, however.

Briefly, Kant's position is this. Man knows but the order of appearance or phenomena, not the order of things-in-themselves or noumena. Now, to know means to change the datum by locating it within a spatio-temporal relationship, whose structure is supplied by the knower through the a priori forms of sensibility. Next man must impose upon this spatio-temporal datum certain other categories that are also rooted in the knower a priori. These are the categories of the understanding (Verstand ): Quantity, Quality, Relation and Modality. Causality is contained as a subdivision of Relation. Together with the forms of space and time, these categories are constitutive of experience, as opposed to the ideas of reason (Vernunft ), which can only be regulative of experience. Previous philosophy erred in confusing the regulative function of ideas with the constitutive functions of the categories. The categories (including causality) are valid when applied to the phenomenal order, but not valid when applied beyond this to the noumenal order. To attempt the latter is to court transcendental illusion (or metaphysics, as Kant understood it). Nevertheless, such a tendency is natural to man and he must always be wary lest he give in to it.

Since Kant allowed a valid but restricted use of causality and other categories within the phenomenal order, he felt that he had preserved the legitimate character of the positive sciences. But maintaining the inapplicability of such categories to the noumenal order led Kant to conclude that metaphysics was impossible as a science. For Kant, then, man does not discover causality in the order of things; rather, he prescribes it and imposes it upon the phenomena in order to render them intelligible (Prolegomena to Any Future Metaphysics, a. 36). Interestingly enough, Kant himself refers causality to the noumenal order, an error he specifically warns against (confer, Prolegomena, a. 13, Remark 2, and Critique of Pure Reason, Introduction, 1). While Kant's general position is understandable in the light of his conceptualism, it is not amenable to a philosophy of moderate realism.

Hegel renders Kantian thought more idealistic, accounting for causality by an unfolding of Absolute Mind, although the process is somewhat obscure. To a considerable extent, the Cartesian demand for clear and distinct ideas and for certitude is at the root of the denial or misunderstanding of causality in modern philosophy. It is true that causality is fundamentally a mystery and therefore lacks the clarity one might desire as an optimum. But opaque though it may be, its certitude is guaranteed by man's direct insight into the real. That this insight is limited can readily be granted.

POSITIVISM AND MODERN SCIENCE

In the main, contemporary philosophy follows the pattern set by its predecessors. positivism accepts causality only as invariable sequence, and this is really to deny its acceptance. pragmatism, while granting the usefulness of the concept of cause, remains close to positivism. Current scientific empiricism generally regards causality as a convention. Representative of both positivism and scientific empiricism, Moritz Schlick of the Vienna Circle says, "The sentence: 'A follows necessarily from B,' so far as content is concerned, is completely identical with the sentence: 'In every case where the state A occurs, the state B follows,' and says nothing more whatsoever"(Philosophy of Nature, tr. A. Van Zeppelin, New York 1949, 89). Charles Sanders peirce reduced efficient cause to its effect and its effect to an irreducible fact. Thus, for him, there are only facts. "The existence of a fact is equivalent to the existence of its consequence. Thus if the consequences of a supposed fact exist, then, so does the supposed fact for the pragmatist"(Values in a Universe of Chance, ed. P. Wiener, Garden City, N.Y. 1958, 129). Rudolf Carnap and Phillip Frank look upon cause as a convention; A. S. Eddington, L. Boltzmann, and E. Mach see nature as acausal.

With the increasing mathematization of the sciences, causality is rapidly losing all dynamical significance and becoming more statistical. Contributing to this view is the current tendency among modern scientists to investigate logical constructs, instead of the world of reality itself. Yet there are indications of a resurgence of interest in causality among philosophers of science such as Mario Bunge and perhaps the future will see a reinstatement of traditional notions.

CONCLUSION

The principle of causality must be seen and grasped in the sensory order, but by an intellectual rather than by a sensory act (see causality, principle of). Consequently, nominalism and empiricism, in denying such an ability to man, are logically forced to deny causality as having no more than psychological value. Conceptualism is itself little more than a refined associationism, a position whose depths were adequately plumbed by Hume. Hence, unless one grants the epistemological position of moderate realism, they will be led to reject causality as metaphysically and scientifically unverifiable. Yet the doctrine of causes is of greatest importance, not only for philosophy and theology, but for the sciences as well. Causality is precisely what enables these disciplines to discern connections and acquire certitude, instead of merely accumulating facts. The manipulation of nature does not require such a doctrine, but an understanding of nature does. For without causality, man necessarily becomes limited to the order of opinion and thereby hopelessly frustrated in his quest for knowledge.

See Also: metaphysics; metaphysics, validity of; instrumental causality

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[g. f kreyche]