We are partial to people with whom we share special relationships--if someone is your child, parent, or friend, you wouldn't treat them as you would a stranger. But is partiality justified, and if so, why? Partiality presents a theory of the reasons supporting special treatment within special relationships and explores the vexing problem of how we might reconcile the moral value of these relationships with competing claims of impartial morality. Simon Keller explains that in order to understand why we give special treatment to our family and friends, we need to understand how people come to matter in their own rights. Keller first presents two main accounts of partiality: the projects view, on which reasons of partiality arise from the place that people take within our lives and our commitments, and the relationships view, on which relationships themselves contain fundamental value or reason-giving force. Keller then argues that neither view is satisfactory because neither captures the experience of acting well within special relationships. Instead, Keller defends the individuals view, on which reasons of partiality arise from the value of the individuals with whom our relationships are shared. He defends this view by saying that we must accept that two people, whether friend or stranger, can have the same value, even as their value makes different demands upon people with whom they share different relationships. Keller explores the implications of this claim within a wider understanding of morality and our relationships with groups, institutions, and countries.