Imagine you are standing at the edge of a chasm. You need to get to the other side. The leap is possible — just barely — but you cannot know in advance whether you will make it. Does believing you can make the leap make it more likely that you will?

Most people's instinct is to say: the belief is irrelevant. The physics is the physics. What you believe about it does not change the distance. William James thought that was wrong — and not just for athletic feats but for a much broader and more important category of human decisions.

In this episode, Shawn and Claire take on one of the most controversial and most practically useful arguments in the history of American philosophy. James's central claim is this: there is a class of decisions, forced, significant, and not resolvable by waiting for more evidence, where withholding belief unti ...