In the dystopian novel Nineteen Eighty-Four, thoughtcrime, also known as crimethink in the official language of Newspeak, is the offense of thinking in ways not approved by the ruling Ingsoc party. It describes the intellectual actions of a person who entertains and holds politically unacceptable thoughts; thus the government of The Party controls the speech, actions, and thoughts of the citizens of Oceania.

https://en.wikipedia.org/wiki/Thoughtcrime