In the traditional Jewish liturgy, a man thanks God daily for not having been made a gentile, a woman, or a slave. Yoel Kahn traces the history of this prayer from its extra-Jewish origins to the present, demonstrating how different generations and communities understood the significance of these words.

Marginalized and persecuted groups used this prayer to mark the boundary between "us" and "them," affirming their own identity and sense of purpose. After the medieval Church seized and burned books it considered offensive, new, coded formulations of the three blessings emerged as forms of...