Drawn from the Prussian Academy edition of Kant's collected works, these letters make it possible to trace the development of Kant's thought from his earliest worries about the topics discussed in the Critique of Pure Reason to his attempts in later life to meet the objections of his critics and erstwhile disciples.  "Perhaps the major value of these writings is their demonstration of Kant's own attitude towards his philosophical works."—Paul Arthur Schilpp, Saturday Review