I discussed Quantum Bayesian theory here about three weeks ago. But now that I know what to look for, it has become easier to find more about it, so I come back to it. Early this year, the William & Mary blog ran an interview with Hans Christian von Baeyer, who believes that QB-ism (which he pronounces "cubism" as in Picasso) is nothing less than the "future of physics." He regrets that advocates of QBism have yet to get it into physics textbooks. But there are "hundreds of articles and conference proceedings" that deal with it, so he is hoping admission into the canon, with the dozen or so older interpretations of quantum mechanics, will come soon. Von Baeyer also makes reference to "an excellent article" that was added to the Stanford Encyclopedia of Philosophy in December 2016. So, after finishing up the interview, I went there. The actual title of that article is evidence that this is an appropriate thing to be discussing in a blo...