Twenty-first century philosophy has been drawn into a false opposition between speculation and critique. In this important intervention, Nathan Brown argues that the key to overcoming this antinomy is rethinking the relation between rationalism and empiricism. If Kant’s transcendental philosophy attempted to displace the opposing claims of those competing schools, any speculative critique of Kant will have to reopen and consider anew the conflict and complementarity of reason and experience. Rationalist Empiricism shows that the capacity of reason and experience to both extend and delimit one another has always been at the core of philosophy and science, and that coordinating their discrepant powers is what enables speculation to move forward in concert with critique. Sweeping across ancient, modern, and contemporary philosophy, as well as political theory, science, and art, Brown engages with such major thinkers as Plato, Descartes, Hume, Hegel, Marx, Heidegger, Bachelard, Althusser, Badiou, and Meillassoux, while showing how the concepts he develops illuminate recent projects in the science of measurement and experimental digital photography. With conceptual originality and argumentative precision, Rationalist Empiricism is a book that reconfigures the history and the future of philosophy, politics, and aesthetics.