I agree that "language can control thought" in the sense of parent post and in the sense of the idea of Newspeak wouldn't work. In a free society, the language should naturally evolve to be able to express every important social concept, similar to how creoles form.
On the other hand, that is not to say that an authority can't use language (in the sense of diction) and linguistic censorship as a powerful vehicle to shape thought. Many examples of this exist. Here are some real-world examples
* Modern Hebrew to foster an Israeli identity.
* Sanskritization of Hindustani into an Hindu-Urdu distinction of identity.
* Heavy and active Internet censorship of diction in China to reinforce what topics are taboo for social discussion or treasonous, and remind that Big Brother is watching.
On the other hand, that is not to say that an authority can't use language (in the sense of diction) and linguistic censorship as a powerful vehicle to shape thought. Many examples of this exist. Here are some real-world examples
* Modern Hebrew to foster an Israeli identity.
* Sanskritization of Hindustani into an Hindu-Urdu distinction of identity.
* Heavy and active Internet censorship of diction in China to reinforce what topics are taboo for social discussion or treasonous, and remind that Big Brother is watching.