CAUSALITY, PRINCIPLE OF

The principle of causality has been variously stated in the history of philosophy. Among such formulations are the following: Every effect has a cause. Every contingent being has a cause. Whatever is reduced from potency to act is reduced by something already in act. Whatever comes to be has a cause. What is, has sufficient reason for its existing (see sufficient reason, principle of).

Different Evaluations. With the exception of empiricists, nominalists, and skeptics, the vast majority of philosophers have all agreed on the validity of the principle of causality. However, dispute has taken place with respect to the limits of its valid use. For example, I. kant accepted the proposition as synthetic a priori, hence as capable of extending man's knowledge, as well as being universal and necessary. Nonetheless, he restricted its employment to the order of phenomena, refusing to permit it a legitimate role in the interpretation of noumena. Others have argued as to whether the law of causality is a self-evident principle, or a demonstrable conclusion. Still others have viewed the proposition as analytic or synthetic or both.

All agree that the casual proposition is not established by the presentation of evidence that this effect was produced by that cause—an individual fact easily verified empirically. Rather, the proposition is one that asserts necessity and claims universality. Usually, however, it is not viewed as applicable to being as such, but only to created or finite being.

Many positivist philosophers, as well as a number of linguistic analysts, admit the universality of the causal proposition, but only because they view it as a tautology. From the viewpoint of the formulation, "Every effect demands a cause," if effect and cause be taken as correlatives, the proposition does seem to differ in no way from the statement, "A is A". Such thinkers claim the proposition is certain only because of the syntax of language. Accordingly, for them, its certainty can be guaranteed only at the expense of sacrificing content.

Initially, perhaps the most basic question that can be asked about the causal proposition is this: Is it necessary that when something comes to be, it does so under the influence of another? This question should be understood as applying to the coming to be of any act, substantial or accidental; to any change; and even to creation. Those maintaining the validity of the causal proposition answer this question in the affirmative. Immediately, the subsequent problems arise. Why is such a necessity demanded, and how does one know this? The necessity cannot be simply a psychological necessity, i.e., one on the part of the knower, as propose by David hume; rather, it must be an ontological necessity.

Some seek this necessity through an analysis of the concept of cause, as though a conceptual analysis of contingent being could reveal its relation to a cause. Yet neither the concept of being nor its contraction to that of finite being implies dependence upon a cause. The reason is quite clear. As St. thomas aquinas puts it, "Relation to its cause if not part of the definition of a thing caused" (Summa Theologiae 1a, 44.1 ad 1). Causality is thoroughly existential, and since existence is not contained in the concept—which pertains to the essential order—no amount of conceptual analysis can reveal the exercise of causality. Hume's rejection of causality as real may well be explained by his having searched for it where it could not be found, i.e., in the order of conceptual analysis.

Justification of the Principle. To justify the causal proposition, then, one must show that he being of a finite thing is from another and that this is necessarily so. This truth is comprehended in the real order through judgment and reasoning, not through mere logical analysis. Thus St. Thomas continues: "Still it [the relation to the cause] follows as a result of what belongs to its nature. For from the fact that a thing is a being by participation, it follows that it is caused. Hence, such a being cannot be without being caused, just as a man cannot be without having the faculty of laughing" (ibid ). But how does one know that a creature is a "being by participation"? This follows from the fact that its essence and existence are really distinct principles. In short, whatever a finite being possesses, it has from its essence or what results from its essence (as a property), or from something nonessential and extrinsic to it. Since creatures are many, since there is in each a composition of potency and act, and since no creature has its existential necessity from itself, its existence must be from another. Its being therefore is ab alio (see essence and existence; participation).

When it has been established that the being of a creature comes necessarily from without, the causal proposition is itself established. "Whatever participates in something, receives what it participates from that from which it participates; and to this extent that from which it participates is its cause" (De subs. sep. 3; C. gent. 2.15). Because only God has existence in virtue of His essence, whatever else has existence has it through the action of another, i.e. God. This consequent then is the causal proposition states on the highest metaphysical plane. To put it differently, the moment one sees that the essence of creatures manifests an indifference to existence, at that moment he can grasp that any creatural act demands influx from another. This again is to state the causal principle, not merely as applying in a particular case, but as having universal validity for the realm of finite being.

Although the validity of the causal proposition is seen in concrete experience, induction and abstraction are required to render its formulation universal. Summing up the views of J. Owens (see bibliography), one can state that the causal proposition is not analytic with respect to a consideration of the ere concept of contingent being; however, it is analytic with respect to a judgment wherein one comes to grips with the existential order. Thus, the nominalist, in refusing to accept an intellectual insight into the real, is consistent in denying real meaning to the universal validity of the causal proposition. For the causal principle is no more sensible per se than is substance.

In light of the causal proposition one sees that all things, either ultimately or proximately, bear some relationship to each other; that there is an existential bond in the order of being; and that the sciences, and especially metaphysic, possess validity.

See Also: metaphysics, validity of; first principles.

Bibliography: m. j. adler, ed., The Great Ideas: A Syntopicon of Great Books of the Western World, 2 v. (Chicago 1952) 1:155–178. l. de raeymaeker, The Philosophy of Being, tr. e. h. ziegelmeyer (St. Louis 1954). b. gerrity, Nature, Knowledge and God (Milwaukee 1947). j. owens, "The Causal Proposition—Principle or Conclusion?" The Modern Schoolman 32 (1954–55) 159–171, 257–270, 323–339.

[g. f. kreyche]