The Qing conquest theory proposes that the actions and policies of the Manchu-led Qing dynasty held China back, and led to the Great Divergence in which China lost its early modern economic and industrial lead over the West. The theory seeks to explain why Europe could experience an industrial revolution, but China did not. Theory supporters, some of whom may be motivated by anti-Qing sentiment, claim that advances in science and technology and economic development in the Song and Ming dynasties moved China toward a modern age, however, the restrictions placed on commerce and industry and the persecution of non-orthodox thought after the transition from Ming to Qing in the 17th century caused China to gradually stagnate and fall behind the West.