This strikes me as very similar to Fishburn’s proof that P7 implies utility is bounded. (Maybe it’s essentially the same? Need to read more carefully; point is, his proof also works by comparing two St. Petersburg lotteries.). Of course, we only get the problem if we imagine that the St. Petersburg lottery is for utility, rather than for money with decreasing marginal (and in this theory, ultimately bounded) utility...
This strikes me as very similar to Fishburn’s proof that P7 implies utility is bounded. (Maybe it’s essentially the same? Need to read more carefully; point is, his proof also works by comparing two St. Petersburg lotteries.). Of course, we only get the problem if we imagine that the St. Petersburg lottery is for utility, rather than for money with decreasing marginal (and in this theory, ultimately bounded) utility...
Yes, this is Fishburn’s proof, just as a modus tollens rather than a modus ponens.