ABSTRACT
“Existence” is thus intended in the light of Dasein, as “human existence”, and represents a key notion in the fundamental ontology that permits Heidegger to formulate the “question of being”, whose sense is at once conveyed and hidden by the history of metaphysics. Original meanings of the concept of existence should also be noted in the “School of Brentano” aside from the existential as well as existentialist approaches, in a philosophical context characterized by issues of an entirely different order. The plot of related notions of which the concept of existence is systematically part, is as follows: “being”, “reality”, “essence”, “substance”, “fact” and “fiction”; a philosophically wide-ranging plot placed at the intersection of logic and ontology, whose sense radically changes when exposed to the various requirements of the phenomenological research. “Existentialism” – as Sartre affirms – “is a doctrine that makes an authentically human life possible”.
