Hume's self-refuting argument
Hume also failed to come to grips with the fact that on the basis of the bare inductionism he advocated one could never have established the existence of laws, let alone laws that were necessarily true and therefore could not be except what they were…Insofar as he was a sensationist or empiricist philosopher he had to grant equal credibility to the recognition of any fact, usual or unusual.
Partiality for some facts, which meant distrust of other facts, invited uncertainly about all facts. This is why when arguing against miracles Hume switched grounds. From a merely probability argument assign miracles (the trustworthy witnessing of regular recurrences far outweighing that of exceptional events) he went on dismissing entirely the credibility of witnesses (whatever their number, learnedness, and integrity) on behalf of exception or "miraculous" events.
S. Jaki, Miracles and Physics (Christendom Press, 2nd, ed., 1999), 20-21.
I think Hume's views on these two issues are consistent. He holds that laws as necessary connections are unknowable and that we should believe only in regularities, but he's happy to call those regularities laws, as long as you don't think they're necessary connections. He's then a pragmatist about the results of science, and he defines probability as how frequently things have occurred in your experience. He doesn't think we could know probabilities if that means how genuinely likely or possible it is, but probability just means how frequently it happens in your experience. Then we can say that scientific laws have 100% probability, and miracles you haven't witnessed yourself have zero probability. That doesn't mean they're not possible, just as he insists that you don't know if gravity will stop working tomorrow. But within your experience, one always has happened, and the other never has. If you witness a miracle yourself, you know that you've experienced it, and that changes matters. But if someone else tells you of it, whether a live person or an ancient document, you have to give that probability of zero. And the chances of a very honest, reliable person getting it wrong (by hallucination or making a mistake of some sort) or being deceptive are above zero, because you have witnessed that, even if it's not very often. So the thing with positive probability is what you should prefer to the thing with zero probability.
ReplyDeleteIt's a completely consistent position. It's just based on a whole bunch of false assumptions about epistemology, laws, causation, perception, probability, and possibility. I think there are problems within the whole system that can bring it down, but it's not just the juxtaposition of these two things. It's the very foundations of it that are the problem. If Hume is right, he can't trust his reasoning, since reasoning takes time, and all he has is his current perceptions. His memories should be untrustworthy, since the person who experienced those things might not have been him, if there was even such an occurrence to begin with. His belief that he's having impressions in his mind right now is even an assumption, one that someone like Thomas Reid would deny, and Reid's argument is that Hume's skepticism, if taken seriously, should be far more damaging, even to the prospects of doing the philosophy that Hume does, than Hume allows. I think Reid is largely right about that. That's where I think we should push back against Hume.