Rosen's overarching question is how, if at all, rationalism can overcome the split between monism and dualism. Monism-which claims a singular essence for all things-ultimately leads to nihilism, while dualism, which claims multiple, irreducible essences, leads to what Rosen calls "the endless chatter of the history of philosophy." The Science of Logic, he argues, is the fundamental text to offer a new conception of rationalism that might overcome this philosophical split. Leading readers through Hegel's book from beginning to end, Rosen's argument culminates in a masterful chapter on the Idea in Hegel. By fully appreciating the Science of Logic and situating it properly within Hegel's oeuvre, Rosen in turn provides new tools for wrangling with the conceptual puzzles that have brought so many other philosophers to disaster.