Abstract
The concept of action is examined, with particular attention to the ontogenetic origin of actions and their developmental course. It is argued that actions constitute dynamic interactions between an organism and the outside world which, by necessity, have to be future-oriented. The upcoming forces and momenta induced by a movement have to be counteracted before they upset the flow of action and the balance of the body. The encounter with the environment needs to be prepared and controlled. It is argued, furthermore, that the developmental origins of actions are actions and that a future-oriented mode of control is a basic property of movement at all ages. Finally, it is argued that actions develop through action. By actively moving, the child learns about properties that change and properties that remain invariant during the execution of a task, about problems that arise when coordinating with the external world, and about information that makes it possible to steer action in a prospective way. This learningconstitutes the foundation of motor skill.