Four cardinal principles

1. the principle of upholding the socialist path
2. the principle of upholding the people's democratic dictatorship
3. the principle of upholding the leadership of the Communist Party of China, and
4. the principle of upholding Marxist-Leninist-Mao Zedong thought

The four cardinal principles actually marked an relaxation of control over ideology. In stating the four cardinal principles, the implication was that these four topics could not be questioned, but political ideas other than those in the list could be debated.

Moreover, while the principles themselves are not subject to debate, the interpretation of those principles are. There has for example, been extensive debate over the meaning of socialism.