In the midst of the 1960s some of the Slovak philosophers have appropriated the Yugoslavian variant of the praxis philosophy developed at Zagreb University. It was a critical reformist stream with the idea of humanism in its core. The basis of their approach was an understanding of humans as active beings changing the world as well as themselves, their nature being practice. The representatives of this stream developed their uncompromised critique of the official philosophy and totalitarian regime of that time and generally of everything existing, firstly by means of the category of alienation. Although in general they did not transcend the limits of socialist vision of the future, in a broader context their activities supported the reforming process, which found its fulfillment in 1968 and became the main reason for Soviet intervention in former Czechoslovakia.