Blaise Pascal was a 17th century French philosopher, mathematician, physicist, and inventor. As a mathematician, he made many important discoveries including inventing the mechanical calculator at age 19, which laid the foundations for modern computers. As a philosopher, Pascal believed that without a spiritual explanation for human life, people would be left with only dissatisfaction. His most famous work, Pensees, was an unfinished defense of Christianity that used rational arguments and probability theory. Specifically, in his "Wager of Pascal", he argued that given the potentially infinite rewards of believing in God, it was rational to choose faith over non-belief even if the existence of God cannot be proven with certainty.