In order to elucidate in what I find these unquestionable foundations of every pedagogical activity, I shall be compelled to repeat myself, that is, to repeat what I said fifteen years ago in the pedagogical periodical, _Yásnaya Polyána_, which I then published. This repetition will not be tedious for the pedagogues of the new school, because what I then wrote is not exactly forgotten, but has never been considered by the pedagogues,--and yet I still think that just what was expressed by me at that time might have placed pedagogy, as a theory, on a firm foundation. Fifteen years ago, when I took up the matter of popular education without any preconceived theories or views on the subject, with the one desire to advance the matter in a direct and straightforward manner, I, as a teacher in my school, was at once confronted with two questions: (1) What must I teach? and (2) How must I teach it? At that time, even as at the present, there existed the greatest diversity of opinion in the answers to these questions. I know that some pedagogues, who are locked up in their narrow theoretical world, think that there is no other light than what peeps through the windows, and that there is no longer any diversity of opinions. I ask those who think so to observe that it only seems so to them, just as it seems so to the circles that are opposed to them. In the whole mass of people who are interested in education, there exists, as it has existed before, the greatest diversity of opinions. Formerly, just as now, some, in reply to the question of what ought to be taught, said that outside of the rudiments the most useful information for a primary school is obtained from the natural sciences; others, even as now, that that was not necessary, and was even injurious; even as now, some proposed history, or geography, while others denied their necessity; some proposed the Church-Slavic language and grammar, and religion, while others found that, too, superfluous, and ascribed a prime importance to "development." On the question of how to teach there has always been a still greater diversity of answers. The most diversified methods of instructing in reading and arithmetic have been proposed.