How is irony/paradox used in language to manipulate or control thinking in 1984?
The topic of Newspeak is a fascinating one in the way that it becomes a lingual representation of repression and lack of freedom. To me, one of the most interesting insights we are given about Newspeak (a terrifying concept at the best of times) comes in Chapter 5 when Syme and Smith are chatting over coffee. Syme starts talking about his favorite topic, Newspeak, and comments on how it relates to the Big Brother world they are living in at large:
Don't you see that the whole aim of Newspeak is to narrow the range of thought? In the end we shall make thought crime literally impossible, because there will be no words in which to express it. Every concept that can ever be needed, will be expressed by exactly one word, with its meaning rigidly defined and all its subsidiary meanings rubbed out and forgotten. ... Every year fewer and fewer words, and the range of consciousness always a little smaller.
There we have it--the central idea behind Newspeak is to "narrow the range of thought." It is therefore another attempt to control the populace and limit freedom and modes of expression so that Big Brother can have an even firmer hold on his people. The irony lies in the name Newspeak, which suggests a better, more refined way of communicating, whereas in fact it is anything but.