At first reading all of this seems obviously correct. But I think that this argument doesn’t actually work. Why? For two reasons.
First, the conclusion that the author ought to infer is actually much stronger than he seems to realize. This reasoning also entails that it is irrational for someone to believe in the resurrection even if he saw it happen in really compelling circumstances. Imagine someone who literally witnessed the risen Jesus. While having a long conversation with the risen Jesus this person reasons thusly, There are many crazy people in the world who do not know that aren’t entirely sure if they are crazy. Some of these people see dead people who do not really exist. These sorts of hallucinations happen fairly regularly. Far more often than people rising from the dead. So I am probably insane. There is really nothing that the risen Jesus could do to convince this rational philosophical skeptic that he really has risen. No matter how long he stayed and talked. No matter how many other people told him that they too saw it. No matter how much psychological testing he went through nothing could convince him. Crazy people have these experiences too. Crazy people who see things that are not there often see not just one thing, but many things (including people who tell them that there delusions are real.) None of this would ever be able to give the rational philosopher evidence sufficient for belief.
More generally, this problem will arise any time what is being experienced occurs less often than insanity. In such cases, the reasonable thing to do is infer that you are insane.
This conclusion seems far too strong to me. It seems to me as though if one literally saw the risen Jesus and had reasonable evidence that one’s mental faculties were working, then it would be reasonable to believe that it had happened. Thus, I think that we have really good reason to believe that there is something wrong with the above reasoning.
But where does it go wrong?