The lecture held at the University of Freiburg during the winter semester of 1921/22 unfolds the introductory question of a principled formal-indicative definition of philosophy to explicate the categorical structures of the fundamental phenomenon "life" in relation to its basic determination of factuality. The phenomenological analysis of various concepts of life reveals care as the fundamental operational character of factual life, from which the world presents itself in its object sense in the fundamental character of significance, where the objects of the world encounter each other in their respective operational meanings as self-, with-, and environmental. The lecture particularly prepares a phenomenological interpretation of essential parts of Aristotelian philosophy through the analysis of the movement characteristics of factual life, which, however, does not reach execution.