We started with an objection hanging over from our discussion of Part I: would Hume’s rule for accepting or rejecting testimony that is inconsistent with “uniform” experience lead to an unacceptably conservative attitude? In particular, would it mean rejecting the surprising observations that have led to progress in the sciences?
Then we talked about Part II. We wanted to know what distinguishes the arguments in Part I from those in Part II. And we wanted to know whether the arguments in Part II are good ones.
Rutherford was shocked to hear that alpha particles fired at a heavy metal foil bounced back: “It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.”
Rutherford used this experiment to formulate a new theory of the atom. But if he had been following Hume’s rule for reasoning in Part I, should he have told Geiger to get lost? If so, that would suggest that Hume’s rule is no good.
We talked about two things to be said in defense of Hume’s rule.
I fussed around about the first point. I see what it’s saying and agree that this is a big difference between miracles and science. But I worry that Hume has a problem with the first step: there has to be a reason to investigate a strange experiment by repeating it. Hume’s rule seems to say that the initial observation should be ruled out as unworthy of further consideration. That’s the problem I fuss about.
I also worry about whether insisting that we should only believe things that can be replicated wouldn’t amount to begging the question against miracles, that is, assuming that we couldn’t have reason to believe in them in the initial premises of an argument. The point of miracles, after all, is to show that God has decided to speak through a particular person. So, by design, they could not be replicated. If we said that we won’t believe in anything that can’t be replicated, we would be ruling out miracles from the start. At least, that’s the way it looks to me.
I think Patrick’s point is a cleaner answer for Hume. I suspect it would apply in most other cases from the sciences. It would be interesting to see if we could find one where it seems not to apply.
It’s surprisingly difficult to say exactly what the point of Part II is supposed to be. At a minimum, Hume is saying that most reported miracles are not credible. I think he was going after something bigger. I think he was trying to move from a premise about the historical record to conclusions about anyone who claims to have witnessed a miracle. The premise about the historical record is that the overwhelming majority of reported miracles have lacked credibility: those who have reported them have not had the characteristics of reliable witnesses, so the fact that they say something does not give you a reason to believe that it is true. The conclusion is that we should assume that anyone who reports having witnessed a miracle is similarly unreliable. Just as the historical record of the weather gives us reason to predict it will be hot in Los Angeles in July, the historical record of miracles gives us reason to predict that the next person to report a miracle will be unreliable. Thus, according to Hume, we can dismiss that next person’s testimony out of hand, without further investigation.
Kai pushed back against Hume. He said that the lives of the apostles hardly suggested that they experienced much personal gain from professing their beliefs. I noted that martyrs are particularly persuasive in this respect: the fact that they are willing to die for what they believe strongly suggests that they genuinely believe it.
Franklin and Josh had inventive ways of rescuing Hume’s point. But, in a way, they were beside the point. Kai seems to have pushed Hume to doing something he said he didn’t have to do: investigate claims about miracles.
You can distinguish between a stronger and a weaker thing that Hume tried to show:
Weaker: it is quite unlikely that a reported miracle is genuine, so you have good reason not to believe someone who reports having seen a miracle.
Stronger: it is so unlikely that a reported miracle is genuine that you can dismiss it without any further investigation.
Hume certainly seems to have made the stronger point. I think that’s what he was saying here, for example.
As the violations of truth are more common in the testimony concerning religious miracles, than in that concerning any other matter of fact; this must diminish very much the authority of the former testimony, and make us form a general resolution, never to lend any attention to it, with whatever specious pretence it may be covered. (¶38, p. 89)
Taking Kai’s observation to heart leaves me uncertain that Hume could establish this with the arguments in Part II.