He notes that it is not the case that it is always unreasonable or impossible for you to have precise beliefs: in that case precision could serve as a regulative ideal. Precise probabilism does still serve as something of a regulative ideal, but it is the belief of an ideal agent in an idealised evidential position. Idealised evidential positions are approximated by cases where you have a coin of a known bias. Precise probabilists and advocates of IP both agree that precise probabilism is an idealisation, and a regulative ideal. However, they differ as to what kind of idealisation is involved. Precise probabilists think that what precludes us from having precise probabilistic beliefs is merely a lack of computational power and introspective capacity. Imprecise probabilists think that even agents ideal in this sense might (and possibly should) fail to have precise probabilistic beliefs when they are not in an ideal evidential position.