Like Heidegger, Sadra, turns to Being, saying that Being is the subject of philosophy. However, contrary to Heidegger who discovers the meaning of Being by analysing Dasein–i.e., the being of a special kind of being–Sadra keeps himself dealing with Being-as-Such. In the opening of his major work Asfar he tries to demonstrate the primordiality of Being (asalatolwojoud): Being is the root. He fundamentally distinguishes Being from quiddity, existence from essence and asserts that nothing is real except existence or Being– No Being, then no reality or truth; no Being, and no beings nothing ever emerge.
Again, like Heidegger, Sadra says that existence or Being which is reality or truth, is never captured by the mind which can only capture essences and general notions. This does not mean for Sadra, however, that we have no access to the reality of Being (as one may say about Kantian noumenon); rather, we are living in, with, and by Being. Since we are rooted in Being and our minds are emerged from and by Being as its constantly flowing manifestation, we then are always living with/in it.