Seldom, in the history of literature, has a work been more conscientiously and deliberately thought out, or more hastily thrown together, than the _Critique of Pure Reason_. The following is the account which Kant in a letter to Moses Mendelssohn (August 16, 1783) has given of its composition: ”[Though the _Critique_ is] the outcome of reflection which had occupied me for a period of at least twelve years, I brought it to completion in the greatest haste within some four to five months, giving the closest attention to the content, but with little thought of the exposition or of rendering it easy of comprehension by the reader--a decision which I have never regretted, since otherwise, had I any longer delayed, and sought to give it a more popular form, the work would probably never have been completed at all. This defect can, however, be gradually removed, now that the work exists in a rough form.”[2] These statements must be allowed the greater weight as Kant, in another letter (to Garve, August 7, 1783), has given them in almost the same words: “I freely admit that I have not expected that my book should meet with an immediate favourable reception. The exposition of the materials which for more than twelve successive years I had been carefully maturing, was not composed in a sufficiently suitable manner for general comprehension. For the perfecting of its exposition several years would have been required, whereas I brought it to completion in some four to five months, in the fear that, on longer delay, so prolonged a labour might finally become burdensome, and that my increasing years (I am already in my sixtieth year) would perhaps incapacitate me, while I am still the sole possessor of my complete system.”[3] The twelve years here referred to are 1769-1780; the phrase “at least twelve years” indicates Kant’s appreciation of the continuity of his mental development. Hume’s first influence upon Kant is probably to be dated prior to 1760. The choice, however, of the year 1769 is not arbitrary; it is the year of Kant’s adoption of the semi-Critical position recorded in the _Inaugural Dissertation_ (1770).[4] The “four to five months” may be dated in the latter half of 1780. The printing of the _Critique_ was probably commenced in December or January 1780-1781. But the _Critique_ is not merely defective in clearness or popularity of exposition. That is a common failing of metaphysical treatises, especially when they are in the German language, and might pass without special remark. What is much more serious, is that Kant flatly contradicts himself in almost every chapter; and that there is hardly a technical term which is not employed by him in a variety of different and conflicting senses. As a writer, he is the least exact of all the great thinkers.