From metaphysics to practical reason
Throughout the Critique of Pure Reason, as Kant contests the objective validity of metaphysical and theological systems, he also begins to reinterpret them in practical terms. The main epistemological liability of traditional metaphysics, i.e., its tendency to construct worldviews based on orders of ideas without reference to experience, becomes a constructive resource for expanding the parameters of ethical-political thinking. To function in support of practical reason, ideas must be liberated from any pretense to ontological claims. As part of this restructuring, Kant also develops an innovative model of human subjectivity that is crucial to his ethical-political inquiries. Most importantly, our capacity for autonomy resists closed metaphysical systems that fix the status of human beings within hierarchical ordering structures. Autonomy is equally resistant to the mechanistic theories of scientific materialism. The subject traverses both reason and nature, and it is this dynamic twofold quality that allows us to apply practical ideas within existing states of affairs.