Newspeak
From APIDesign
Newspeak is a language primarily designed to support doublethink. In general it is very hard to think about things that you cannot speak about, express in a language. If you control the language you can basically control what people can (easily) think about. The concept has been taken to its extereme in 1984 novell by George Orwell, however every society is in some way relying on this and uses language to supress unwanted thoughts.