1. Concept and problems. The discussion of theory and practice is one of the primary themes of all philosophy. Since it examines the relation between idea and reality, word and deed, consciousness and being, concept and object, thought and action, purpose and history, the discussion of theory and practice could stand for philosophy itself. Where the relevance of theory to practice is denied in a radical scepticism or where they are merged in an undifferentiated identity, philosophy itself ceases to…