In the introduction the author shows the importance of a unified school as one of the signs of equality of men. He historically explains the development of the curriculum as parallel to the development of science and production. But the evelopment of didactics was not parallel to that of the curriculum in the school practice, though the pedagogical reformers pointed to the pedagogical insufficiency of the overloaded teaching plans, curricula and textbooks. The school practice tried to remove the difficulties by a differentiated education of children of different social origin. The socialist conception of the school organisation is based on a unified school and the perspective of universal instruction, education and teaching of all children based on their personal interest and abilities. There are various at the organisation of a unified school, but the author keeps to the conception given by our Education. A ct of the year 1957 about an eleven year universal instruction school and to a two year preparatory school for high schools. In order to arrive at his own settlement of the problem what to teach at an elementary school the author analyses the development of perception in children’s age, its immediate and reflectively orientative character in the sense of I. P. Pavlov. In this connection he emphasizes the importance of language and teacher’s activity in teaching. At an elementary school it is not possible, the author concludes, to transfer knowledge, in teaching the grammar of a language e. g., by deduction from definitions, but in the spirit of the mental development on the basis of direct perception of the phenomena of the language. To build up scientific didactics of this development is an important task of planning of the material, which should not excessively differentiate pupils on the basis of the progress. The author considers the same changes of the method in teaching history, geography and natural science at elementary schools. The author does not limit himself to the criticism of the actual teaching at an elementary school which he finds too abstract and formal, but he shows the way how to remove the abstract teaching material and substitute it with a lively knowledge and correct habits.