Hitherto there have been widely differing interpretations of the contradiction which Kant describes in the Critique of Pure Reason under the headings ‘Dialectics’ and ‘Antinomy of Practical Reason’. This volume documents for the first time the enormous variety of diverging interpretations and presents a text-oriented analysis of antinomy and its resolution which in many respects contradicts the interpretations and assessments widely accepted today. The study demonstrates that antinomy only became possible after Kant had undertaken important revisions of the principles of moral obligation and motive after1781.It demonstrates how the antinomy of practical reason characteristically differs from the antinomies in the Critique of Pure Reason in its structure and function.