Bearing in mind that the law of being in relation to the cognizing subject consists of being-conscious, consciousness, according to Jean-Paul Sartre, supersedes the status of a particular mode of knowledge as internal sense or knowledge as knowledge of oneself, constituting the dimension of being transphenomenal. In this way, based on the phenomenological-ontological-existential principle, Prof. Luiz Carlos Mariano Da Rosa focuses on the relationship between the phenomenon of being and the being of the phenomenon and the irreducibility of the being of the phenomenon to the phenomenon of being, highlighting the process that superimposes the being of the phenomenon on the phenomenal condition and converges to consciousness as being cognisant as it is in a movement that escapes the as it is known, crossing the frontiers of the pre-eminence of knowledge. If consciousness emerges as consciousness of something in a process whose being implies a being that encloses itself as non-conscious and transphenomenal, what imposes itself, according to Sartre, is none other than consciousness as a being that encloses the question of its being as a being that implies another being than itself. Thus, focusing on the event of the appearance of the human existent in relation to being as the discovery of a world and negation as an essential and primordial moment, the article highlights the reason why the human existent in its being implies the possibility of the appearance of nothing in a process that concludes freedom as a condition for the nihilation of nothingness.