Books like Thesen zu Feuerbach

The theses represent the development of perception from being that of sensations to that which relates to practice. The final thesis, which presents a call to action within philosophy also shows how practice must become a relevant and important part in the process of perceiving. Inherently, without practice theories of perception only lead to an interpretation of the world. As such practice applies one to the material conditions and leads to a form of perception which changes the world. In this way it can be seen that practice is the only way in which one may perceive of the material world without falling into contradictions.