  Where the subject-matter of the projected descriptive general account is some practice or institution devised by (more or less adequate exercises of) reason, and addressed to the rational deliberations of individuals and groups, there will normally be no good reason not to prioritise those forms of the practice or institution which are more rational, more reasonable, more responsive to reasons, than other forms of the “same” or analogous practices and institutions. The standard for assessing reasonableness for this theoretical purpose is, in the last analysis, the set of criteria of reasonableness that the descriptive theorist would use in dealing with similar practical issues in his or her own life.