If Immanuel Kant (1724-1804) is undisputedly the most influential late 18th century philosopher, Bernard Bolzano (1781-1848) is increasingly becoming recognized as perhaps the most unjustly neglected early 19th century philosopher. This volume demonstrates that Bolzano was one of the most careful, insightful, and rigorous critics of Kant's 'Critical' philosophy. It includes a complete translation of The New Anti-Kant, which provides a meticulous assessment of the entirety of Kant's Critique of Pure Reason from the perspective of Bolzano's own powerful logico-analytic system of philosophy, as compiled by Franz Prihonsky in collaboration with Bolzano and published in 1850 after Bolzano's death. It also includes a series of essays by leading scholars on the significance of Bolzano's critique of Kant both for current interpretive debates surrounding Kant as well as for contemporary debates in logic, philosophy of perception, epistemology, and ethics. The volume as a whole therefore offers fresh insight into historical developments in post-Kantian and proto-analytic philosophy alike.