Kant's philosophy is difficult at best of times. Paul Guyer's book goes a long way towards a deeper understanding of Kant's philosophy. I bought the book in the hope of a better understanding of Kant's epistemology and also of his moral philosophy. I was not disappointed. I recommend the book to second or third year undergraduate student as well as to post-graduate students who are interested in Kant. Nevertheless, I believe that even the professional philosopher, not yet acquainted with Kant, will profit from Guyer's book as well. As a matter of fact, I recommend it to undergraduates as well as postgraduates especially of the biological sciences. Kant's epistemology should prove of great interest in these sciences. One just has to look at the writings of the scientist Konrad Lorenz who was thoroughly acquainted with Kant, to understand my last remark. I recommend this book wholeheartedly!