In fact, the spectrum of interpretations in quantum mechanics has a close analogue in probability theory.

Note that anyone who acted that way would be silly, and that their error would have little to do with QUANTUM MECHANICS, but mainly with PROBABILITY THEORY. Probability theory is the special case of quantum mechanics in which ones algebra of observables is commutative. (This becomes a theorem in the context of C*-algebra theory.) Quantum mechanics has special features due to the noncommutativity, but probability theory already exhibits certain subtleties of interpretation, which I believe are a large part of what’s at stake here.

— John C. Baez

2009.12.02 Wednesday ACHK