The essays in this collection pull out a few threads from the enormous complexity of "practices-possibilities" problematic. They address the problematic in terms of hermeneutic phenomenology. At stake are the issues of the constitution of meaningful objects by means of interpretative appropriation of possibilities. While becoming confi gured in horizons of possibilities, interrelated practices project constantly possibilities. The interplay of practices' projection and appropriation of possibilities is the kernel of a hermeneutic theory of meaning constitution. The author's aim is to integrate this theory in several scientifi c research programs. The book is compiled from the author's lengthy experience in collaborating with research teams working at projects in hermeneutic phenomenology of science, the double hermeneutics in the construction of practice theory, the existential spatiality in the social sciences, and the hermeneutic projects for political science.