Consider the difference between modern Egyptology wrt the history of the pyramids and the "history" of scientology, Xenu, and alien spirit volcanoes.
The first is far more epistemically legible, the second is pure ideological fantasy (or sci-fi, considering the author. )
There's a much smaller gulf between Principia Mathematica and the history of Egypt - differences in recorded historical facts allow for differing interpretation but the possibilities are constrained and have a huge amount of overlap with hard science - we can be almost as sure that Tutankhamen was a real king as that Abraham Lincoln was president of the US, and the certainty of both having been real probably exceeds five 9's. The probability of Scientology being real, as she is wrote, is probably below 0.1e-100.
From a Bayesian perspective, you can be 100% certain of things like your own subjective experience, and from there you can presume certainty for things whose probability or improbability exceed some threshold - you might never know if Tutankhamen was a nice guy or generally a prick, but his existence is founded within enough other certainties that you can (probably) assign that fact the moniker of "100% real" with great success. The same with "Xenu is cult nonsense."
If we're talking about a list of facts concerning Egypt then I'd agree. But history isn't a list of facts. If it was it would be unreadable. All histories have a narrative (and usually other things, like a political philosophy and a sense of morality). Against the Grain is an obvious example of that. The author here is trying to reduce Against the Grain to a list of verifiable facts and finds that this is very hard.
Religions are also not lists of facts. Most sophisticated believers (and I assume this applies to Scientologists) have a partly metaphorical understanding of their religion.
If we take some extremely far-fetched history, let's say David Irving's Holocaust denial, I would say that (unfortunately) the gap between Against the Grain and Irving is much smaller than the gap between either history and Principia.
I think we need to define history - you seem to be operating from the definition as a narrative anchored to a list of facts, but I consider history to be the collection of facts of themselves, from which narratives can be derived. If the narrative is bounded by the limits of the facts (dates, correlated recording, carbon dating, artifacts, etc.) then the resulting narrative lacks the potential for inaccuracies. If history is instead a narrative, into which facts are selectively slotted, the uncertainty rapidly reaches a point at which interpretation and belief factor into the history as much or more than dry facts.
I think the trick is requiring that the fundamental narrative of a given history be bounded by science (itself a narrative) in the sense that things are left unknown and unknowable where evidence is lacking or insufficient.
Egyptology is a non scientific, dogmatic narrative into which facts and conclusions are selectively slotted. The "prestige" resulting from British imperialists fetishizing the subject created a mythos of Egypt as some primal, fundamental expression of the beginning of civilization. This mythos is tended and cultivated in modern times by Egyptians and their cultural elites, with their interpretation of history resulting in notoriously poor handling of any science-based revision.
So there is dogmatic and narrative history, and scientific history. Things like the archeology of Clovis culture result in dry, but scientific history. Few people or institutions will encounter perverse incentives in that field. Egyptian heritage and tourism necessitate cooperation with institutions and corrupting outside influences that derogate the resulting narrative.
In the case of religion, there's a great deal of similarity and overlap with histories of the dogmatic sort and both suffer from the issue of the narrative selecting for ideologically convenient facts, instead of a self limiting construction founded in scientific principle.
The worst part is that science itself can be considered an ideology as dogmatic and fraught with perverse incentives as any other story we attach to dry lists of facts. The difference is in the repeatability of direct consequences - we can trust carbon dating, but educated guessing about culture based on parchment fragments that result in a story about thousands of people at a particular point in time has to be weighted similarly to religion or mythology in terms of factuality.
If you choose to believe in science, then everything becomes lists of facts, whether rigorously repeatable tests like carbon dating, or assertions about the beliefs and actions of people thousands of years ago - or about modern cohabitants of this existence. A Bayesian perspective on the deconstructed narratives as lists of facts gives us a methodology to navigate narratives rationally.
The difficulty is in assigning probabilities to the authenticity of a given fact, so - Lincoln 100% existed, Xenu 100% did not.
The modern narrative of Egyptian history (my own understanding of it) is probably 85% scientific or accurate, and the questionable bits are the ones that directly benefit the individuals or institutions that stand to benefit from corrupted or perverse incentives.
Holocaust denial, like flat earth and Bigfoot, is inherently anti-bayesian and requires wilfully abandoning easily verifiable dry facts and rigorously scientific information that is trivially accessible. To believe in such stuff you have to embrace an extreme of skepticism that makes navigating reality impractical at best, either believing everything from a particular authority or rejecting everything outside one's own direct experience.
It's an interesting problem, and I'd like to see a Bayesian history of humanity some day, with a rigorously bounded and annotated set of probabilities attached to every part of the narrative portion of historical stories. Maybe gpt-3 or future transformer models could eke out such a system.
> I think we need to define history - you seem to be operating from the definition as a narrative anchored to a list of facts, but I consider history to be the collection of facts of themselves, from which narratives can be derived.
But historians don't write down lists of facts. I think you'll find, as the author does, that if you try to extract from a work of history a list of facts, you're going to end up with things that are highly debatable. Some of these things will be moral judgements, some will be assertions about human psychology and motivations, some will be implicit metaphysical beliefs. It might be worthwhile to write all this down but historians won't do it voluntarily because many of these things are embarrassing to admit.
I would say that sophisticated readers of history already have a somewhat Bayesian perspective. They implicitly attach probabilities to historical narratives and update those probabilities as new information arises. It's not rigorous but it seems crazy to me to expect that it could be made rigorous.
I don't agree with your dismissal of old Egyptology. I think you're buying into an Edward Said/postcolonialism narrative that is terribly flawed. I also don't think you can easily label historical narratives as "anti-bayesian" or obviously wrong. I think Holocause denial is obviously wrong but it's not on the same level as flat-earth.
The first is far more epistemically legible, the second is pure ideological fantasy (or sci-fi, considering the author. )
There's a much smaller gulf between Principia Mathematica and the history of Egypt - differences in recorded historical facts allow for differing interpretation but the possibilities are constrained and have a huge amount of overlap with hard science - we can be almost as sure that Tutankhamen was a real king as that Abraham Lincoln was president of the US, and the certainty of both having been real probably exceeds five 9's. The probability of Scientology being real, as she is wrote, is probably below 0.1e-100.
From a Bayesian perspective, you can be 100% certain of things like your own subjective experience, and from there you can presume certainty for things whose probability or improbability exceed some threshold - you might never know if Tutankhamen was a nice guy or generally a prick, but his existence is founded within enough other certainties that you can (probably) assign that fact the moniker of "100% real" with great success. The same with "Xenu is cult nonsense."