We have just traced the imaginary plan of a history of pedagogy rather than the exact outline of the series of lessons which this book contains. However, we have approached this ideal as nearly as we have been able, by attempting to group about the principal philosophical and moral ideas the systems of education which they have inspired; by endeavoring to retain whatever is essential; by adding to the first rapid sketches studied and elaborate portraits; by ever mingling with the expositions of doctrines and the analysis of important works the study of practical methods and the examination of actual institutions; and, finally, by penetrating the thought of the great educators, to learn from them how they became such, and by following them, as they have united practice with theory, in the particular systems of education which they have directed with success.[2] DIVISION OF THE HISTORY OF PEDAGOGY.--The abundance and the variety of pedagogical questions, the great number of thinkers who have written upon education, in a word, the complexity of the subject, might inspire the historian of pedagogy with the idea of dividing his work, and of distributing his studies into several series. For example, it would be possible to write the history of education in general by itself, and then the history of instruction, which is but an element of education. As education itself comprises three parts, physical education, intellectual education, and moral education, there would be an opportunity for three series of distinct studies on these different subjects. But these divisions would present grave inconveniences. In general, the opinions of an educator are not susceptible of division; there is a connection between his manner of regarding the matter of instruction and the solution he gives to educational questions proper. One mode of thinking pervades his theories or his practice in the matter of moral discipline, and his ideas on intellectual education. It is, then, necessary to consider each of the different systems of education as a whole. Perhaps a better order of division would be that which, without regard to chronological order, should distinguish all pedagogical doctrines and applications into a certain number of schools, and connect all educators with certain general tendencies: as the ascetic tendency, that of the fathers of the church, for example, and of the middle ages; the utilitarian tendency of Locke, and of a great number of moderns; the pessimism of Port Royal, the optimism of Fénelon; the literary school of the humanists of the Renaissance, and the scientific school of Diderot and of Condorcet. Such a mode of procedure would have its interest, because in the manifestations of educational thought so apparently different it would sharply distinguish certain uniform principles which reappear at all periods of history; but this would be rather a philosophy of the history of education than a simple history of pedagogy.