 The answer seems clear: reasonable trust is practically rational trust. The question of when one may rationally trust another may thus be resolved by a decision-theoretic calculation, factoring in the extent to which one’s evidence supports the potential trustee’s trustworthiness and the utilities of the possible outcomes, given one’s intended aims. The exercise of practical reasoning does include mental acts which are epistemically evaluable, however. When one takes it to be true in practical reasoning that someone will prove trustworthy, that mental act may be more or less epistemically rational: it would break the evidentialist norm to employ in a decision-theoretic calculation a credence that does not match one’s available evidence. In many situations, it will be practically rational, given one’s intentions, to trust another person only if one believes, or, at least, believes with high probability, that the person will prove trustworthy. In such situations it is also often the case, as already noted, that we don’t have adequate evidence in advance that this person will be trustworthy in this particular respect. Yet, affording high credence to a person’s trustworthiness may still be epistemically rational given wider available evidence of, for example, the person’s past friendliness and trustworthiness in other matters, or, if the person is a stranger, of our shared social experience that trusting others generally elicits a trustworthy response. Nevertheless, it can still be rational—practically rational, that is—to trust another when we don’t have adequate evidence that they will prove trustworthy. In a life-threatening situation, for example, it may be rational to trust unlikely rescuers if they are the only ones available. Or, when we have wider aims, it may be practically rational to trust those without a record of trustworthiness, as with ‘educative’ and ‘therapeutic’ trust where people are trusted for the sake of their development or rehabilitation as trustworthy persons. Being in established relationships of friendship with others, too, can also require commitment to continue to trust them even in the face of evidence that, otherwise, would make it reasonable to believe them unworthy of trust.