The author of this article calls upon socialist educationists to be among the first to help the party tear the mask of the so-called socialism with a human face of right-wing opportunists, enemies of socialism and enemies of the Soviet Union. It is the duty of socialist teachers not only because they are among the foremost helpers of the party, but also because they have plenty of arguments to expose the slyness of their criticisms. The most militant among the ≫critics≪ were those who were notorious as early as the 1945—48 period. They treacherously criticized socialist pedagogy, the socialist teacher and the system of the socialist all-in school. The treachery of their criticism can be exposed very clearly by their criticism of the socialist all-in school system and their uncritical admiration of the feudal- bourgeois educational system in the pre-Munich republic. Researches carried out in the period of the first republic already showed quite clearly that the educational system in question was feudal bourgeois, dualistic, in which the ≫gymnasium≪ (grammar school type of secondary school) was a means of social stratification of pupils. Even if the bourgeoisie could not but defend this socially unjust, reactionary educational system, it was simultaneously bound in public at least to pay lip service to the idea of a socially just system of all-in schools, which the progressive forces in that period not only advocated but also fought for. The democratization of education could only be realized under the rule of the working class. The Communist Party of Czechoslovakia in the first republic already had a democratic school programme of its own. Influenced by the study of the Soviet school and Soviet pedagogy, the Communists joined the Slovak national uprising in 1944 with a concrete socialist school programme. Consistent democratization of the educational system to benefit the common people is announced by the National Front government programme of April 4th, 1945 — the Košice Government Programme. On April 21st, 1948, the Constituent National Assembly passes the ≫Basic Arrangement of Uniform Education Act≪. Under this Act all schools pass under the state control, compulsory school attendance is extended from eight to nine years, and the schools, especially those of the second grade of the educational system (i. e. for 11 to 15-year-old) are unified. This Education Act rebuilds the vertical, feudal-bourgeois, anti-democratic educational system into a horizontal, democratic educational system of the socialist all-in school. By the unification of all second grade schools organizational conditions were created for an unprecedented development of education at all grades of the educational system. First of all, within 20 years (1948—68) this Act made it possible for the national network of nursery schools to be extended from 4,661 to 8,067, i. e. by 73 per cent, and the number of children in them increased from 205,416 to 371,013, i. e. by 81 per cent; it was only due to this Act, too, that conditions were created for the organizational level of the compulsory school to be raised in such a way that the number of these schools fell from 14,286 to 10,947, i. e. by nearly 25 per cent, even though the number of pupils in these schools increased from 1,523,290 to 2,052,526, i. e. by nearly 35 per cent. The number of secondary general schools increased from 229 to 349, i. e. by more than 52 per cent, and the number of pupils in them from 70,440 to 107,978, i. e. by 53 per cent. But the most revolutionary increase was that in vocational schools and universities. Even though the number of technical and secondary vocational schools only increased from 643 to 699, i. e. by 9 per cent, the number of pupils in them increased from 92,610 to 278,685, i. e. more than threefold, which means a rise of more than 200 per cent. The number of universities increased from 22 to 35 and the number of faculties from 55 to 98. The number of university students increased from 57,700 to 137,654, i. e. by nearly 140 per cent. The number of teachers at general schools increased from 54,569 to 105,520, which means it almost doubled, and the number of professors and readers in the universities increased from 1,370 to 3,631, i. e. by 165 per cent, and the number of the other members of the university teaching staff increased from 4,495 to 12,772, i. e. by more than 184 per cent. The basic Education Act also created the necessary conditions for the further development of socialist education in Czechoslovakia. Naturally, we have not succeeded in solving all the problems in this very short period of only a quarter of a century. In spite of all our efforts we have not been able to find e. g. a successful model of the secondary general polytechnical school, we have not succeeded in bringing school close to life, the politico-ideological education and the partisanship in education have not yet been raised to the necessary level. But experience has been gained that without the Communist party approach in education there can be no scientific approach, because the scientific approach and the party approach are conditioned by each other. The twenty-five years of building the socialist school in Czechoslovakia represent a lot of experience. Under the leadership of the Communist Party of Czechoslovakia the Czechoslovak school in this period has been transformed from an instrument of the class domination of the bourgeoisie into an instrument of the working class in building a socialist society. It is not only a period of revolutionary achievements, but also a period of great lessons.