Rational persons disagree about some important matters and that even a high degree of rationality in people is consistent with great diversity among them. This chapter addresses the question: is there a kind of relativity built into the notion of rationality, or at least consistent with it, say, relativity to one's own experience or culture? If many kinds of grounds may sustain rational elements in persons, there should be a plurality of rational ideals. But there are also constant elements that play a prominent role in the make-up of rational persons, least controversially a measure of simple logicality. It is argued that an adequate theory of rationality must do justice both to the variability that marks different ranges of experience and diverse cultural settings and to the constancies that, because of important elements in our humanity, can be expected as recurring elements, at least in any civilized society.
Keywords: rationality, experience, culture, plurality, rational ideals, logicality