 Again, there are parallels here with the literature in ethics, which has treated moral perception as not so much a matter of identifying some new fact in a situation of moral choice, as of understanding the relative importance of various facts, and grasping which in particular deserve attention or call for some practical response. For example, the virtuous person may not be able to list some further fact concerning the circumstances of various people in a crowded railway carriage, but the fact that a particular passenger is over-burdened by their bags, and in some discomfort because they have to stand, may weigh with this person. This fact may become salient in their perception of the scene, and salience here may be a matter, at least in part, of their felt response to the passenger and their predicament. (Compare Blum 1994, pp. 31–33.)