An exploration of ways that discord binds rather than divides communal life, through an ethnography of French Muslim activism. The conversation about Islam in France is framed by the presumption that Muslim communities are a threat to secular solidarity or fraternité . In the face of state repression, French Muslims have not closed ranks around a narrow range of voices; instead, Kirsten Wesselhoeft finds that young Muslim activists have continued to purposefully spark debate about the values that anchor community life. Wesselhoeft argues that such disagreements, far from dividing communities, actually constitute a form of belonging. Some activists call this ethic "fraternal critique," and Wesselhoeft finds in it profound insights about the place for critique in civic life. The French state has reacted to Muslim solidarity with repression, but Wesselhoeft argues that unity need not come at the expense of dissent. Instead, fraternal critique can teach us how to build communities that are worth fighting over and fighting for.