Being a rational agent is difficult. But why? We often think of it as psychological challenge, which it is. But that’s not the only obstacle. Among other things, we really need to get a better grip on what rationality is. Joshua Rothman explores some recent literature on the subject. According to several authors, rationality demands a flexibility of mind that can accommodate probabilities as well as facts, self-awareness about one’s level of confidence concerning the available evidence, self-reflection about one’s own habits of thought, and interpersonal knowledge. Furthermore, rationality must be integrated with other human capacities, such as honesty, empathy, and so on.