Book excerpt: Under what circumstances can love generate moral reasons for action? Are there morally appropriate ways to love? Can an occurrence of love or a failure to love constitute a moral failure? Is it better to love morally good people? This volume explores the moral dimensions of love through the lenses of political philosophy, psychology, and neuroscience. It attempts to discern how various social norms affect our experience and understanding of love, how love, relates to other affective states such as emotions and desires, and how love influences and is influenced by reason. What love is affects what love ought to be. Conversely, our ideas of what love ought to be partly determined by our conception of what love is.