It is first proposed that materialist dialectic, as a theory of knowledge, but also as a method of thinking, has evolved due to identifiable developments in the sciences. In particular, game theory and catastrophe theory deal with certain conflictual processes without even using the notion of dialectic. Conversely, the geography of perception tries to go beyond behaviorism. This appears possible if the relations between the object of perception and the thinking subject are reformulated using such dialectical categories as the notion of contradiction, when studying, for example, the links between « what is » and « what could be ».