The Will to Believe, and Other Essays in Popular Philosophy by William James
1. A living option is one in which both hypotheses are live ones. If
I say to you: "Be a theosophist or be a Mohammedan," it is probably a
dead option, because for you neither hypothesis is likely to be alive.
But if I say: "Be an agnostic or be a Christian," it is otherwise:
trained as you are, each hypothesis makes some appeal, however small,
to your belief.