In Communities of Kinship: Retrieving Christian Practices of Solidarity with Lepers as a Paradigm for Overcoming Exclusion of Older People, Carlo Calleja describes kinship as a moral category, arguing that practicing kinship with others can cultivate virtues that shape the character of the agent. Contemporary Western society tends to focus on kinship as the sharing of blood ties or genetic material. On the other hand, the spiritual kinship that is proposed by religions tends to be exclusive and often nominal. For this reason, Calleja proposes practices and structures of solidaristic kinship, which involves sharing in the suffering of the other person. Finding parallels between the exclusion of lepers and the efforts of Christian communities to reforge kinship bonds with them in ancient and medieval times, he argues that communities of kinship with older persons can help cultivate the virtues needed for the flourishing of oneself and society.