 Once this starting point is granted, the question arises whether all truths are equally non-instrumentally good to believe, and all falsehoods equally bad. There is reason to think not: it would be a warped kind of concern for the truth that led someone to memorise phone books rather than doing science, on the grounds that this is more efficiently generates epistemic value. The concept of naturalness seems potentially useful in explaining which truths are most valuable to believe. Indeed, if we are willing to apply ‘natural’ to propositions as well as properties, the following simple generalization looks tenable: the more natural a proposition is, the better it is to know it or believe it or have high confidence in it if it is true, and (one might add) the worse it is to believe it or have high confidence in it if it is false.