Deep friendship may express profound loyalty, but so too may virulent nationalism. What can and should we say about this Janus-faced virtue of the will? This volume explores at length the contours of an important and troubling virtue -- its cognates, contrasts, and perversions; its strengths and weaknesses; its awkward relations with universal morality; its oppositional form and limits; as well as the ways in which it functions in various associative connections, such as friendship and familial relations, organizations and professions, nations, countries, and religious tradition.