The book addresses two main areas of Kant¿s theoretical philosophy: the doctrine of transcendental idealism and various central aspects of the arguments from the Metaphysical and Transcendental Deductions, as well as the relation between the deduction argument and idealism. Among the topics covered are the nature of objective validity, the role and function of transcendental logic in relation to general or formal logic, the possibility of contradictory thoughts, the meaning of the Leitfaden at A79 and the unity of cognition, the two-steps-in-one-proof interpretation and categorial instantiation, categorial illusion, Strawson¿s transcendental argument, the persistently perplexing question of the derivation of the categories, and the relation between apperception,