According to George Orwell, "The purpose of Newspeak was not only to provide a medium of expression for the world-view and mental habits proper to the devotees of Ing Soc, but to make all other modes of thought impossible. Its vocabulary was so constructed as to give exact and often very subtle expression to every meaning that a Party member could properly wish to express, while excluding all other meaning and also the possibility of arriving at them by indirect methods. This was done partly by the invention of new words, but chiefly by eliminating undesirable words and stripping such words as remained of unorthodox meanings, and so far as possible of all secondary meaning whatever." The idea that language influences worldview is linguistic relativity.
For example, the word "free" still existed in Newspeak but could only be used in terms of something not being possessed as in, "the dog is free from lice" or, "this field is free from weeds." It could not be used in terms of being able to do as one pleases, as in "free choice" or "free will" since these concepts no longer existed. Newspeak was designed not to extend but to diminish the range of thought, and this purpose was indirectly assisted by cutting the choice of words down to a minimum. Any redundancies in the English language were removed.
As Orwell further states, "By 2050—earlier, probably—all real knowledge of Oldspeak will have disappeared. The whole literature of the past will have been destroyed. Chaucer, Shakespeare,Milton, Byron—they'll exist only in Newspeak versions, not merely changed into something different, but actually contradictory of what they used to be. Even the literature of the Party will change. Even the slogans will change. How could you have a slogan like "freedom is slavery" when the concept of freedom has been abolished? The whole climate of thought will be different. In fact there will be no thought, as we understand it now. Orthodoxy means not thinking—not needing to think. Orthodoxy is unconsciousness."
To Control Thought:
1) Only one acceptable interpretation or thought.
2) No other meanings of vocabulary acceptable
3) Exclude any other meaning from those terms
4) Invention of new words