...added to my large class of “sanity-complete” propositions: propositions defined by the property that if I doubt any one of them, then there’s scarcely any part of the historical record that I shouldn’t doubt.
Maybe nothing, but it's strange that Aaronson identifies "sanity" primarily or significantly with buying into the bulk of the historical record. Does sanity really require being approximately right about history?
No - but it does require that you recognize that "There is a very thorough conspiracy that has convinced the entire known world of falsehoods about events as recent as 50 years ago" is significantly less likely than "The majority of the historical record is true."
Rationality quotes time!
The usual rules: