During the monopoly of Marxist-Leninist philosophy in Slovakia the critical opi_nions and reformation attempts played an important role. Although rooted in the ruling doctrine, they in fact transcended it. The first reformation stream appeared in the frame of historical studies of Slovak philosophy as soon as in the first half of the 1950s. It stood up against the interpretation of Marxist philosophy by a Russian philosopher Zhdanow, especially against his vulgarizing sociological and historical-philosophical scheme. The orthodox Marxist-Leninists together with the leadership of the Communist party rejected the reformation processes as the defle_xions from the "genuine Marxist philosophy". The critical philosophers showed the dogmatic unfruitfullness of the Stalinist philosophy, they supported the rationalist tendencies within Marxism, rejected the reducing the culture to class struggle, the philosophy to the the struggle between materialism and idealism etc. They disintegrated the official philosophy from inside and pursued the criticism of social and political situations as such.