Pascal’s wager is an argument in philosophy presented by the seventeenth-century French philosopher, theologian, mathematician and physicist, Blaise Pascal (1623–1662). It posits that humans bet with their lives that God either exists or does not.
Pascal argues that a rational person should live as though God exists and seek to believe in God. If God does not actually exist, such a person will have only a finite loss (some pleasures, luxury, etc.), whereas if God does exist, he stands to receive infinite gains (as represented by eternity in Heaven) and avoid infinite losses (eternity in Hell).
Pascal’s Wager was based on the idea of the Christian God, though similar arguments have occurred in other religious traditions. The original wager was set out in Pascal’s posthumously published Pensées (“Thoughts”), an assembly of previously unpublished notes.
Historically, Pascal’s wager was groundbreaking because it charted new territory in probability theory, marked the first formal use of decision theory, existentialism, pragmatism, and voluntarism.