Actions are basically not ontological entities but interpretational constructs, interpreted entities which are in a certain sense semantically impregnated. A Philosophy of interpretational constructs does not only apply to Action Theory, but offers a rather general epistemological approach which can even lead to a new first Philosophy consisting of a sort of methodological interpretationism which can also lend itself to a special kind of transcendental interpretaionism. With respect to Action Theory, however, many problems of a purely causalist or reductionists or materialist Theory of Action may be solved or avoided if cross-level theories including semantic constituents are used to handle the traditional problems of purely physicalist models of actions, on the one hand, and merely linguistic models, on the other hand. An interdisciplinary approach utilizing physical as well as semantic and mental constituents for action description is outlined in the paper.