Rramjet, thank you for your substantive response, I hope we are both moving the can further down the road. Allow me another good kick at it:
Background knowledge is the crucial difference that lets us readily accept the judge's word in the one scenario but far less so the other. To spell it out: We know stores exist but we don't know that aliens exist.
In your terms, I suppose we can consider that the evidentiary bar for the store and for the alien stories are equally high: but what you're failing to understand is that the work of getting over the bar is aided greatly by the background knowledge that stores exist. We're very near the bar already before the stranger even says a word. We don't have to do the heavy lifting of proving that stores exist - we already know it. But we don't know aliens already exist (at least not anywhere near the surety with which we know stores exist). That's why we need more for the alien story than for the store story - there's more to demonstrate because we already know stores exist.
We were talking about the evidence for the claims “I went to the store” and “I was abducted by aliens”. You have shifted the debate to talking about evidence for the claims “Stores exist” and “ET exists”. In that context:
The evidence for a store is the physical evidence that they exist. You can touch them. You can physically walk into them and interact with them.
We don’t have that evidence for ET. However, if we did, it would be
precisely the same standard of evidence that we have for the store. In both cases it would be
physical evidence.
Getting back to the original claims, we can see that for the first claim (I went to the store) we don’t need the evidence for the store itself – because we already accept that evidence exists – so all we need do is assess whether the judge has the credibility to stand as a witness we can believe.
When it comes to the second claim (I was abducted by aliens) we do need evidence for the alien itself – evidence we don’t have – but if we
did we would accept
the same level of evidence as we did (do) for the store – that is physical evidence – but has anything changed about our assessment of the credibility of the judge?
Surely our assessment of the credibility of the judge is not dependent on context…? Either we assess the judge to be able to tell us the truth in all circumstances or we do not. Surely we cannot “pick and choose” the judge’s credibility based merely on our own belief systems. Surely it is illegitimate to say “I don’t believe that claim, so the judge must be lying”? Perhaps you can say (as you do) that the judge must be lying because we don’t have evidence for aliens - I would contend that is illegitimate, but that is a separate argument…
The whole point is that our belief in either claim is predicated on sufficient evidence either way. There is nothing extraordinary about the nature of that evidence. The evidence we would accept for both the store and the alien is
physical evidence (nothing extraordinary about that) and the credibility of the judge will be based on other types of evidence (not extraordinary either).
So it becomes legitimate to ask, why you might want “extraordinary evidence” for a belief in one claim and not the other, when clearly we can arrive at a belief in
either claim without resorting to extraordinary evidence.
