This chapter argues that a standard principle of charity argument cannot establish an explanatory role for strong rationality, even if it might do so for a weaker notion of rationality. The notion of rationality is normative there is something wrong with a person who is not rational. The folk-psychological notion of rationality involves many different aspects of the concept, but most importantly, it includes some reasonable level of instrumental rationality and consistency. Expected Utility Theory (EUT) can be, and sometimes is, understood as just a normative theory. However, this strategy also risks making EUT tautological. The theory of bounded rationality has given rise to a lot of research on how people actually make decisions. For example, according to Kahneman and Tversky prospect theory, people systematically violate the dictates of EUT by being more averse to losses than they are motivated by opportunities to gain. Normative principles do not work in mysterious ways. The causes of human behavior are obviously natural.