Historicality and existential necessity in Martin Heidegger’s Being and Time

One of the main results of the existential analytic of Being and Time is the priority of the possible over the actual in the way of being proper to human existence. Possibility has a foundational meaning in the modal structuring of existence. In this paper, I present the sketch of an existential notion of necessity. Following a path opened by Oskar Becker, I try to uncover the existentially necessary at the limits of projection on existential possibilities, that is, at the authentic historicality of Dasein. Focusing upon the notion of destiny, I present a concept of existential necessity based on the simplicity and obligation of an existence that is conditioned by finitude and finite freedom. Keywords: Heidegger, modalities, necessity, historicality, ontology.