The objective of this investigation has been to interpret Heidegger's existential analysis and our argument has been that this analysis designates a phenomenological interpretation of subjectivity. What characterizes this phenomenon is that it is essentially related to itself and that it is a condition of possibility for the appearance of entities. In other words, what characterizes the phenomenological concept of subjectivity does not depart from the traditional modern interpretation of the same phenomenon in regard to its distinctive character. The difference between the phenomenological concept of subjectivity and the traditional modern conception of subjectivity concerns location. Whereas the latter typically is introduced as a worldless thing-like entity, the former is presented as a Being-in-the-world that is not a thing. But the basic principles of phenomenology allow the relocation of subjectivity in the world without eliminating the peculiarity of subjectivity. Dasein is both a subject and in the world which means that its being related to its own being and its appearance as the condition of possibility of appearances takes place in the world.