Every kind of behavior comes from a certain thought, and it is not necessarily a signal of action. the more people make full use of language tools to exchange ideas freely, the more they can achieve correct understanding to dominate more rational actions. Therefore, suppressing speech is often not an action to prevent mistakes, but to prevent deliberate actions, and the result must be that if the pressure is large enough, people will be passive, and if the pressure is small, people will move at will.
The most likely meaning of the passage is that restricting speech restricts thought.