Hegel examines the speculative concept of “being-in-itself”. We can take this to stand for nature or material substance. He argues that the thoughtful examination of the concept allows inference to the second moment of his “dialectical science” of concepts. As a tautology, “being-in-itself” — i.e., being qua being, A = A — begs the question why one (the thinker) has even to state, to express, to say, to make explicit that ‘being is being’ at all. Thus, reflecting on the idea — the idea of simple identity — we are repelled, as it were, from its emptiness or lack of content, toward recognition that its being thought implies already being beyond it, beyond simple identity, implying non-identity or difference. As thinking, we go beyond, transcend, find ourselves other than being-in-itself. This is how Hegel explains the thought of Descartes, where Descartes finds his subjectivity, his “I think” to be something radically alien, transcending the being of objective substance. In Hegel’s logic of concepts, Cartesian dualism is sublated, Aufheben, meaning negated but preserved. The Cartesian opposition between thought and being is negated as something considered naturally given or fixed (as Descartes took it to be), but is preserved as an event, as a temporal moment in which “spirit” (i.e., thinking) recognizes itself as the negative, the inverse (the “inverted world”) of being or nature considered as something merely in-itself. Being or nature becomes for-itself a transcending of being in-itself.