Why is it considered illogical to have a new fact that supports a previously-unsupported spiritual claim?

Question

This question is about the general ideas of acceptance and rejection in scientific fields, and while largely theoretical, is based on a conversation I'm having with a self-styled skeptic. I'm hoping for some clarity on how the thought process works, how I think it should work, and how my discussion partner thinks it should work.

Imagine a claim that was made 5000 years ago (ca. 3000 BCE, at the dawn of writing), recorded as a part of some kind of myth about "the gods" in ancient Mesopotamia somewhere. It was warped out of any recognizable truth and remained a part of a myth until a recent discovery confirmed that the one part (not the whole myth) was actually a point of fact that was difficult to prove, yet which met some level of "extraordinary proof" that allows at least a degree of acceptance as demonstrably not false. People have believed it for thousands of years, but only as a part of a doctrine of false or possibly specious claims (untested at best, demonstrably false at worst, much like many claims in the field of mythology which tend to be metaphors anyway).

Now imagine that this singular claim is the founding point for an entire system of beliefs, most of which are specious at best, and at worst superstitious. And yes, people who believe are taking the revelation as "proof" that their beliefs are real. But it doesn't work that way in reality, of course. The validation of the singular claim does not necessarily validate everything else connected to it.

So then, why is it considered illogical to accept the support for the thing that actually does hold up, while perfectly logical to throw out the baby with the bathwater and require wholesale acceptance or rejection of the whole myth? Can't we accept parts which are simply true, in and of themselves, rather than needing to reject a truth because it supports a myth? Or is it a requirement to concede the entire myth as false and ignore the single claim that validates the one portion?

Thanks for any input on this. Let me know if any clarification is needed.

Answer 1

If there is a logical argument from one preposition, P, that has an undetermined truth value:

i.e. P implies Q, and Q implies R, and R implies S.

Then if you later discover P is true, you must accept S is true.

If your interlocutor understood that such a logical argument existed, they could reasonable argue that you must accept that either the entire system (P, Q, R & S) are true, or that P is false. Evidence for the provisional acceptance of P would also be evidence for the provisional acceptance of S. (And vice-versa: Evidence that S was false would also be evidence that P was false.)

If you don't agree that such a logical argument exists, you don't need to make that choice. In particular rejecting a proposition "because it supports a myth" is an "appeal to consequences" fallacy.

I am guessing that the disagreement was because your interlocutor believed an argument with those implications existed, and you did not agree or were not aware of it.

Answer 2

As I understand it, although it is believed that P implies Q, R, S, etc. It is not a fact! Therefore, even if new evidence "supports/proves" P, it does not follow that this evidence directly supports/proves Q, etc., nor indirectly (through P).