What is disclosed in the questioning of the human being in post-humanism? Addressing this question in congruence with Heidegger's questioning of being in Being and Time, we end up with two discoveries: first, that the characteristic of Dasein, as the being of the questioning, already carries the same implications as the post-human figure, and second, that questioning in this sense is indicative of the effort of realizing anew scientific space for conceptualizing the human being as non-substantialist. Conceived of in this way, however, post-humanism is a result of a very human effort indeed.