George Orwell, the author of Nineteen Eighty Four recognised that by limiting language one limits thought.
If you do not have the words for a concept, you can’t think of it. By removing words, by limiting language, thought is constrained.
Consider today, the kind of language being used by the American President.
Simple words, with little meaning, repeated, over and again. The depth of an idea, the complexity of an event is made ‘Bad’ or ‘Good’ without explanation. If one obeys him they do so without question or understanding, because nothing is spelled out.
Limit speech, limit thought. Limiting thought makes people easier to control. Repeat the same words over and again, saying virtually nothing, exposing no facts, and the public, with it’s curtailed ability to think can not respond, only do what they are told.