I regard all principal and non-principal positions of the aspects of a contradiction as involved in this mutual change.
Some people think that this is not true of certain contradictions. For instance, in the contradiction between the productive forces and the relations of production, the productive forces are the principal aspect; in the contradiction between theory and practice, practice is the principal aspect; in the contradiction between the economic base and the superstructure, the economic base is the principal aspect; and there is no change in their respective positions.[4-557] It should be realized that under normal conditions, and viewed from a materialist point of view, they really are unchanging and absolute things; however, there are historically many particular situations in which they do change. The productive forces, practice, and the economic base generally play the principal and decisive role; whoever denies this is not a materialist. But it must also be admitted that sometimes[4-558] such aspects as the relations of production, theory, and the superstructure in turn manifest themselves in the principal and decisive role. When it is impossible for the productive forces to develop without a change in the relations of production, then the change in the relations of production plays the principal and decisive role. The creation and advocacy of revolutionary theory plays the principal and decisive role in those times of which Lenin said, “Without revolutionary theory there can be no revolutionary movement”. When a task, no matter which, has to be performed, but there is as yet no guiding line, method, plan, or policy, the principal and decisive thing is to decide on a guiding line, method, plan, or policy. When the superstructure (politics, culture, etc.) obstructs the development of the economic base, political and cultural changes become principal and decisive. Are we going against materialism when we say this? No. The reason is that we recognize that in the general development of history the material determines the mental.[4-559] We also – and indeed must – recognize the reaction of mental on material things.[4-560] This does not go against materialism; on the contrary, it avoids mechanical materialism and firmly upholds dialectical materialism.