Formal epistemologists often claim that our credences should be representable by a probability function. Complete probabilistic coherence, however, is only possible for ideal agents, raising the question of how this requirement relates to our everyday judgments concerning rationality. One possible answer is that being rational is a contextual matter, that the standards for rationality change along with the situation. Just like who counts as tall changes depending on whether we are considering toddlers or basketball players, perhaps what counts as rational shifts according to whether we are considering ideal agents or creatures more like ourselves. Even though a number of formal epistemologists have endorsed this type of solution, I will argue that there is no way to spell out this contextual account that can make sense of our everyday judgments about rationality. Those who defend probabilistic coherence requirements will need an alternative account of the relationship between real and ideal rationality.

正式认识论者经常声称我们的信任应该可以用概率函数来表示。然而，完全概率连贯性仅适用于理想的智能体，这就提出了这一要求与我们关于理性的日常判断有何关联的问题。一个可能的答案是，理性是一个上下文问题，理性的标准随着情况而变化。就像根据我们考虑的是幼儿还是篮球运动员而将谁算作高大的变化一样，也许根据我们考虑的是理想的代理人还是更像我们自己的生物，什么算作理性转变。尽管许多正式的认识论者认可这种解决方案，我会争辩说，没有办法阐明这种能够理解我们对理性的日常判断的上下文描述。那些为概率连贯性要求辩护的人将需要对真实理性与理想理性之间的关系进行另一种解释。