Man is in a position to act because he has the ability to discover causal relations which determine change and becoming in the universe. Acting requires and presupposes the category of causality. Only a man who sees the world in the light of causality is fitted to act. In this sense we may say that causality is a category of action. The category means and ends presupposes the category cause and effect. In a world without causality and regularity of phenomena there would be no field for human reasoning and human action. Such a world would be a chaos in which man would be at a loss to find any orientation and guidance. Man is not even capable of imagining the conditions of such a chaotic universe.
Where man does not see any causal relation, he cannot act. This statement is not reversible. Even when he knows the causal relation involved, man cannot act if he is not in a position to influence the cause.
The archetype of causality research was: where and how must I interfere in order to divert the course of events from the way it would go in the absence of my interference in a direction which better suits my wishes? In this sense man raises the question: who or what is at the bottom of things? He searches for the regularity and the "law," because he wants to interfere. Only later was this search more extensively interpreted by metaphysics as a search after the ultimate cause of being and existence. Centuries were needed to bring these exaggerated and extravagant ideas back again to the more modest question of where one must interfere or should one be able to interfere in order to attain this or that end.
The treatment accorded to the problem of causality in the last decades has been, due to a confusion brought about by some eminent physicists, rather unsatisfactory. We may hope that this unpleasant chapter in the history of philosophy will be a warning to future philosophers. [p. 23]
There are changes whose causes are, at least for the present time, unknown to us. Sometimes we succeed in acquiring a partial knowledge so that we are able to say: in 70 per cent of all cases A results in B, in the remaining cases in C, or even in D, E, F, and so on. In order to substitute for this fragmentary information more precise information it would be necessary to break up A into its elements. As long as this is not achieved, we must acquiesce in what is called a statistical law. But this does not affect the praxeological meaning of causality. Total or partial ignorance in some areas does not demolish the category of causality.
The philosophical, epistemological, and metaphysical problems of causality and of imperfect induction are beyond the scope of praxeology. We must simply establish the fact that in order to act, man must know the causal relationship between events, processes, or states of affairs. And only as far as he knows this relationship, can his action attain the ends sought. We are fully aware that in asserting this we are moving in a circle. For the evidence that we have correctly perceived a causal relation is provided only by the fact that action guided by this knowledge results in the expected outcome. But we cannot avoid this vicious circular evidence precisely because causality is a category of action. And because it is such a category, praxeology cannot help bestowing some attention on this fundamental problem of philosophy.