Hume on Rumors
“When anyone tells me that he saw a dead man restored to life,” wrote David Hume, “I immediately consider with myself whether it be more probable that this person should either deceive or be deceived, or that the fact which he relates should have really happened.”
I have modernized the punctuation a bit, but the idea is clear. If someone tells you something, a good question to ask is, Which is more likely:
- The person telling me this is wrong, or
- The event actually happened
For instance, your friend tells you he was abducted by a UFO and subjected to an anal probe. It’s possible. But unlikely. So which is more likely—That he’s wrong? Or that he actually was abducted and subjected to an anal probe?
Hume actually wasn’t writing about rumors. He was writing about “miracles.” But the common sense observation is still useful. Now, there are all sorts of discussions by philosophers about this common sense maxim, some of which are quite critical and fault Hume for not taking account of advances in probability theory of which he should have been aware. Others seem to get bogged down in giving a Bayesian account of this maxim.
It’s a common sense tool that help me think clearly day to day. And that, I think, is enough.