This seems to be a common "overselling" of Savage's ideas (and other axiomatic approaches to decision theory / probability). In order to decide that the axioms apply, you really need to understand them in detail rather than just accept that they are commonsensical.

Ok, I'll work on making that more precise. Also, "consistent in commonsesnsical ways" is not the same as "commonsensical." We'll see why that's important in two posts.

Note that I'm not saying that logical uncertainty shouldn't be handled using probabilities, just that the amount of work shown in this post seems way too low to determine that it should.

I'd agree, especially since we are still two posts away from seeing the actual problem of logical uncertainty.

I seem to have promised you unrealistic payoff - probably because I didn't think I could keep peoples' interest by just talking about the foundations of probability for a while before any promise of payoff. Ditto for summarizing and then putting in links for people who want more rather than quoting all the definitions, desiderata, and proofs of key results.