Marx and Engels lay keen emphasis on the issue of development. Rather than simply from the perspective of economy, they consider it in terms of the global development of capitalism as well as related class conflict and the reconstruction of productive relations. Due to the imbalanced development in the capitalist system, multi-layer political and economic relations exist in the capitalist system at the international level, which makes class conflict in the capitalist system inevitable, and the consequent reconstruction of capitalist productive relations intensifies the imbalanced development in the capitalist system in turn. However, such an imbalanced system has created the premise for the further development of human society, and lays a solid material foundation for a more advanced social system. Hence, Marx and Engels believe that capitalism has positive significance to the development of human society.