The word “doublethink” was first used by George Orwell in his novel 1984. It means the power of holding two contradictory beliefs in one’s mind simultaneously, and accepting both of them.
Orwell invented the word but the practice existed long before he was born. First Kings 18 describes the contest between Elijah and the prophets of Baal to determine who is the true God. Here is what Elijah said to the people.
And Elijah came near to all the people and said, “How long will you go limping between two different opinions? If the LORD is God, follow him; but if Baal, then follow him.”
1 Kings 18:21
Some of the people practiced doublethink by worshipping both Baal and the LORD. God condemned this practice and demanded that they choose one side or the other.