This article tries to find a way out of the epistemological problem and the self-body question in Cartesian dualism in light of Mulla Sadra Shirazi's philosophy. There are possibilities in Sadra's thought which make achieving this objective possible. The argument develops in three steps to bring into focus the subject, the object, and knowledge. Concerning the subject, Mulla Sadra's philosophy demonstrates that self/soul and body are unified through modal boundedness (tqyid-i al-sha'ni) which is called existential objectivity in which the self-body (...) duality makes no sense. In his discussion on the object, Shirazi points out that philosophical truths such as necessity, causality, oneness, and so on are unified to the external being and the objective reality in an integrative way (taqyid-i al-indimadji) having existential objectivity. Regarding knowledge, Mulla Sadra emphasizes the existential character of knowledge rather than its essentiality. Therefore, the existence or the existential unity between the knower, the known, and the knowledge overcome the self-body and self-external world cleavages. Because of its unity with the body, the self is present in the external world and perceives the world or the external facts, and then some ideas of the external worlds will appear in mind. (shrink)