Well, Bayesian updates are no good unless you have the right hypothesis. That might be what you mean.
Not quite, prior to this. We could say, for example, that having a scratchy throat is evidence that one has a cold. Bayes allows us to formalize this claim somehow. But it does not actually tell us what a “scratchy throat”, or indeed a “cold”, is. A perfect reasoner does not need this—they need the possible laws of physics, a sensible prior, and very good computational skills, and concept formation is not relevant to them. But a bounded Bayesian does not have this luxury—we cannot actually draw the boundary in concept-space around these terms, we certainly cannot quantify how fuzzy the boundary is, and yet we find ourselves able to do mostly-sensible probability updates anyway, because prior to a Bayesian approach, we are somehow good at concept-grouping.
Incidentally, this is why I say metaphysics is harder for a Bayesian—a perfect reasoner, or a bounded inferrentialist, does not require that their concept formation is perfect. Making metaphysical categories is helpful but optional for them. But a bounded Bayesian needs to do it and do it well, and it’s not clear how this is possible—you do not get it from priors and you do not get it from the update rule, and indeed these two things alone are not sufficient materials for a bounded Bayesian update.
Not quite, prior to this. We could say, for example, that having a scratchy throat is evidence that one has a cold. Bayes allows us to formalize this claim somehow. But it does not actually tell us what a “scratchy throat”, or indeed a “cold”, is. A perfect reasoner does not need this—they need the possible laws of physics, a sensible prior, and very good computational skills, and concept formation is not relevant to them. But a bounded Bayesian does not have this luxury—we cannot actually draw the boundary in concept-space around these terms, we certainly cannot quantify how fuzzy the boundary is, and yet we find ourselves able to do mostly-sensible probability updates anyway, because prior to a Bayesian approach, we are somehow good at concept-grouping.
Incidentally, this is why I say metaphysics is harder for a Bayesian—a perfect reasoner, or a bounded inferrentialist, does not require that their concept formation is perfect. Making metaphysical categories is helpful but optional for them. But a bounded Bayesian needs to do it and do it well, and it’s not clear how this is possible—you do not get it from priors and you do not get it from the update rule, and indeed these two things alone are not sufficient materials for a bounded Bayesian update.