Had people been unable to hold contradictory beliefs and values, he suggests, it would have been impossible to establish human culture.

Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them.

He described it in his most famous novel, 1984, as holding two contradictory beliefs simultaneously and accepting both of them.

These models call into question how one can simultaneously hold contradictory beliefs (static paradox) and deceive oneself without rendering one's intentions ineffective (dynamic/strategic paradox).