This essay highlights Balthasar's kenoticism as the key notion that allows him to relate intimately but also to distinguish clearly between (metaphysical) philosophy and (Trinitarian) theology. Through a careful study of Balthasar's metaphysics and kenoticism, this essay shows that Balthasar's Trilogy develops, in light of its kenotic reading of the immanent Trinity, a kenotically expressed metaphysics. The result is a reciprocal elucidation between theology and philosophy and a genuinely Trinitarian ontology, that is, a deeply Trinitarian account of the metaphysical constitution of finite being that still distinguishes between the philosophical and the theological disciplines.