I admit I wasn’t very clear—let me clarify: I see people making decisions to act based solely on their degree of belief in a particular statement (see the four examples in the original post). To figure out whether a particular action is in your interests, it’s never sufficient just to evaluate probabilities: you can see in the expected utility equation that you simply can’t get away from evaluating your utility function.
I admit I wasn’t very clear—let me clarify: I see people making decisions to act based solely on their degree of belief in a particular statement (see the four examples in the original post). To figure out whether a particular action is in your interests, it’s never sufficient just to evaluate probabilities: you can see in the expected utility equation that you simply can’t get away from evaluating your utility function.