The basic form of man’s existence in nature is work. Work is an expression of human activity, the starting point and the medium of the subject’s realization and self-realization. The humanism of man and his history is neither a given fact nor a state; it is a task, an effort, an endeavour, it is the ethos as well as the pathos of intensive creative self-realization. The fact that the changing of circumstances and human activities form a unity can be understood and rationally interpreted as revolutionary practice only. Human activities are nothing spiritual, they are activities carried out with the participation of consciousness in various forms of the division of labour, changing, in the historical context, its extent and countent. Marx’s idea of revolutionary practice is the basis of socialist pedagogy, the fundamental principle of the educational activities of the school practice, as a harmony between 'the changes of conditions and changes of man. Marx understands man as a being who forms and transforms himself by his own social activities. The humanism contained in Marx’s work is a socialist humanism and man becomes, a really free, creative, socially active subject in a society free from exploitation and private property. The active role of man and the social revolutionary practice for the essence of socialist pedagogy.