It is commonly held that because of his obvious misinterpretations of Berkeley's philosophy, which he called dogmatic or visionary and mystical idealism, Kant thereby betrayed a gross misunderstanding of that philosopher. The theory advanced to explain this is that Kant was not acquainted with any of Berkeley's writings, but obtained his knowledge from inadequate second-hand sources.1 This theory is supported by the fact that Kant's knowledge of the English language was most imperfect. He never read a single English book. Coupled with this is the apparently acceptable fact that there were no German translations of Berkeley's works in existence before 1781, the year of publication of the first edition of the Critique of Pure Reason.2 In that year, there appeared a German translation of Berkeley's Three Dialogues between Hylas and Philonous.3 This work was therefore available to Kant before he published his Prolegomena to any Future Metaphysics (1783)4 and the second edition of the Critique (1787). But such is the nature of Kant's account of Berkeley's doctrine in these works that, on the common view, Kant neglected to avail himself of the opportunity to read it. Thus, previous assessments of the evidence, internal and external, have produced the view that Kant knew nothing of Berkeley's writings at first hand and, accordingly, misunderstood and misinterpreted his teaching. From this, it follows, although the commentators have omitted to stress this conclusion, that Kant's many attempted refutations of dogmatic idealism fail before they begin. The above is not only the accepted view, backed by seemingly strong evidence; it is the most plausible. Nevertheless, it is almost wholly mistaken, as I shall show.