(Is Bayesianism even a word? Should it be? The suffix "ism" sets off warning lights for me.)
Visitors to LessWrong may come away with the impression that they need to be Bayesians to be rational, or to fit in here. But most people are a long way from the point where learning Bayesian thought patterns is the most time-effective thing they can do to improve their rationality. Most of the insights available on LessWrong don't require people to understand Bayes' Theorem (or timeless decision theory).
I'm not calling for any specific change. Just to keep this in mind when writing things in the Wiki, or constructing a rationality workbook.
Not true. Theorem:Bayes is simply the result of more fundamental information-theoretic heuristics, which themselves would be capable, for the same reasons, of generating the same ideas of rationality -- though it would probably require a longer inferential path, which is why Theorem:Bayes seems like it's the grounding principle (rather than the best current operationalism of the true grounding principle).
The use of probabilities itself results from the same heuristics. These grounding heuristics form what I have called "correct reasoning". "Correct reasoning" is the (meta-)heuristic that says a being should use precisely the heuristics that it would be forced to use after starting from an arbitrarily wrong belief set and encountering arbitrarily many instances of informative evidence.
(If one recognizes what heuristics one will move to on encounters with more evidence, one can move to them without waiting for the evidence to arise, on pain of excessively slow updating.)
In a conflict between correct reasoning and Theorem:Bayes, correct reasoning should take precedence.
Therefore, the humans here should say that they are "correct reasoners", not Bayesians.