The Interpretation of Dasein in Terms of Temporality [Zeitlichkeit]* and the Explication of Time as the Transcendental Horizon of the Question of Being†
The Preparatory Fundamental Analysis of Dasein
What is primarily interrogated in the question of the meaning of being  [Sein] is that being [Seiende] which has the character of Dasein. In keeping with its uniqueness, the preparatory existential analytic of Dasein itself needs a prefigurative exposition and delimitation from investigations which seem to run parallel (Chapter One). Bearing in mind the point of departure of the investigation, we must analyze a fundamental structure of Dasein: being-in-the-world [In-der-Welt-sein] (Chapter Two). This "a priori" of the interpretation of Dasein is not a structure which is pieced together, but rather a structure which is primordially and constantly whole. It grants various perspectives on the factors which constitute it. These factors are to be kept constantly in view, bearing in mind the preceding whole of this structure. Thus, we have as the object of our analysis: the world in its worldliness (Chapter Three), being-in-the-world as being a self and being with others (Chapter Four), being-in as such (Chapter Five). On the basis of the analysis of this fundamental structure, a preliminary demonstration of the being of Dasein is possible. Its existential meaning is care (Chapter Six).
* Only this in the part published.
† Cf. the Marburg lecture, SS 1927 (Die Grundprobleme der Phiinomenologie).