EN
The present paper consists of two parts dealing with the closely interrelated questions of action, the situation of action and interpretation. At first the concept of action, and behaviour related to it is defined in relation to motives in this part of the paper. The concepts of the possibility and ability of action as well as of the situation of action are introduced, and the major determining factors of actions are pointed out on a general level. Finally, in the first part the broader and narrower interpretations of the concept of need are introduced and the concept of need in a narrower sense of the term is defined.