This book presents the first critical evaluation of all four of Kant's antinomies of pure reason by applying the instruments of formal logic and by testing the validity of the antinomies against the criteria of modern science and natural philosophy.The author first reconstructs at length the 'metaphysical deduction' of the transcendental and cosmological ideas of reason. Kant's doctrine of the antinomies of pure reason is then placed in the context of his theoretical philosophy, and this is followed by a philological and formal-logical analysis of the four antinomies. Using the findings of modern science and natural philosophy, the author finally presents a systematic evaluation of Kant's argumentation.