Most comprehensive of all of the educational writings of Comenius is the _Great didactic_. It was planned in 1628, while yet in the full possession of his vigor, before misfortune had hampered his usefulness and persecution had made him a wanderer. Written originally in the Czech, it was translated into the Latin and published at Amsterdam in 1657. The original Czech manuscript was discovered at Lissa in 1841, and presented to the museum at Prague; but the Austrian censors of the press forbade its publication because Comenius was a Bohemian exile (!). Through the exertions of the museum authorities, however, it was allowed to be printed in 1849. Professor Laurie gave English readers a summary of the _Great didactic_ in his _Life and educational works of John Amos Comenius_ (London, 1883); but the first complete translation was made by Mr. M. W. Keatinge of Edinburgh in 1896. The full title is: _The great didactic setting forth the whole art of teaching all things to all men; or a certain inducement to found such schools in all parishes, towns, and villages of every Christian kingdom that the entire youth of both sexes, none being excepted, shall quickly, pleasantly, and thoroughly become learned in the sciences, pure in morals, trained in piety, and in this manner instructed in all things necessary for the present and future life, in which, with respect to everything that is suggested, its fundamental principles are set forth from the essential nature of the matter, its truth is proved by examples, from the several mechanical arts its order is clearly set forth in years, months, days, and hours; and finally an easy and sure method is shown by which it can be pleasantly brought into existence_. The purpose of the _Great didactic_, as announced by Comenius in the preface, is to seek and find a method of instruction by which teachers may teach less, but learners may learn more; schools may be the scene of less noise, aversion, and useless labor, but of more leisure, enjoyment, and solid progress; the Christian community have less darkness, perplexity, and dissension, but more light, peace, and rest. He promises in his “greeting” an “art of teaching all things to all men, and of teaching them with certainty, so that the result cannot fail.” Among the uses of such an art he notes the advantage (1) to parents, that they may know that if correct methods have been employed with unerring accuracy, it is impossible that the desired result should not follow; (2) to teachers, who, without a knowledge of this art, try in turn first one plan and then another—a course which involves a tedious waste of time and energy; and (3) to schools, that they may become places of amusement, houses of delight and attraction, and that they may cause learning to flourish. Such, in brief, are fundamental principles of a philosophy of education. How well those principles were elaborated and applied will be seen in the exposition of his writings which follows.