Theories of Knowledge (Karl Marx) In his early years of writing, Karl Marx's ideas were similar to American Pragmatism, especially his ideas about epistemology. He defines truth in a pragmatic fashion and explains cognition in terms of practical needs of the human being. While some of his ideas were not followed to their logical conclusion, nor made sense, the fundamentals of his epistemology contain valuable ideas which can be viewed as furthering pragmatism as a respectable philosophy. His theory of cognition states that cognition is a biolo ....