This text identifies the core of Carl Schmitt's thought as political theology, that is, political theorizing that claims to have its ultimate ground in the revelation of a mysterious or supra-rational God. This radical, but half-hidden, theological foundation unifies Schmitt's often difficult and complex oeuvre and by relating this religious dimension to Shmitt's support for National Socialism and his continuing anti-Semitism, the text examines the irreconcilable differences between political theology and political philosophy.