In this article Aristotleś conception of moving principle of human action is described. The author is interested in Aristotleś way of combining cyclical moving of effective causes with entelecheia, a direction to highest good or happines, as a purposive cause of human action. This idea can be illustrated as a cycle of effective causes centralised around the purposive cause. This reconstruction of Aristotleś conception of causation of human action can be useful in process of contemporary syntetisis human action theories. Acending (...) to the author, Aristotleś idea that the essence of rationality lies in human action is a first step to solving the problem of nature of human being, and his conception of moving principles of human action is congenial anticipation of some aspects of contemporary theories of rational action and choice. (shrink)