Blaise Pascal was a Seventeenth-Century mathematician with an interest in gambling. Oh, yes: mathematicians aren’t geeky loners with no hobbies. They live the high life. Évariste Galois even died in a duel at the age of twenty over the honour of a girl, but not before founding a major branch of abstract algebra. Not that the French had it all their own way. John Joseph Sylvester, founder of the American Journal of Mathematics, had in his youth been expelled from the University of London for stealing a knife from the refectory, with the purpose of attacking a fellow student.
But back to Pascal. The interest in gambling paid off mathematically, because in collaboration with his fellow-countryman Pierre de Fermat, he developed the basis for probability theory. He also laid the foundations for what would come to be called ‘game theory’, and did important work on basic questions in physics.
Unfortunately, Pascal was never a well man, and this gave him a gloomy and introspective outlook. He took to religion.
As someone who had formerly had a scientific turn of mind, Pascal sought to present his beliefs as rational; and he came up with what is now known as “Pascal’s Wager” using some of his mathematical ideas on probability.
Pascal’s Wager says that it is better to believe in God than not, because you have nothing to lose and everything to gain by “betting” that way.
When he published the idea, he argued that, because the existence or non-existence of God was not amenable to human reason, it made sense to make the calculation based on a 50-50 probability of the existence of God. You couldn’t decide one way or the other, so you call it evens. Well, that’s pretty much a crock of a concept. You can apply the same argument to the existence of the flying spaghetti monster or invisible pink unicorns. You can’t prove that they don’t exist, and you can’t prove that they do, but would you say there’s a 50% probability that there is such a thing?
But that gaffe doesn’t blow Pascal’s basic notion out of the water. Even if you thought there was only a one in fourteen million chance that God existed, wouldn’t it make sense to believe, just in case? What do you have to lose? After all, I’ve bought a lottery ticket at exactly those odds, hoping for a big win. Why would I not make the minor investment of belief, because if it pays off, it’s heaven and eternal life and everlasting bliss?
Because a lottery ticket costs a pound. Religious belief costs everything I have and everything I am. Would you bet your life on the existence of invisible pink unicorns?