Several years ago, Professor Winnifred Fallers Sullivan wrote an influential book titled, The Impossibility of Religious Freedom. Sullivan’s core thesis was that protecting “religious” freedom was impossible in contemporary America because nobody can agree, for purposes of the law, about what religion is.

Here is a new book that represents at least an implicit critique of the Sullivan thesis, drawing on very ancient sources to define religious freedom today: The Possibility of Religious Freedom: Early Natural Law and the Abrahamic Faiths (Cambridge University Press), by Karen Taliaferro.

“Religious freedom is one of the most debated and controversial human rights in contemporary public discourse. At once a universally held human right and a flash point in the political sphere, religious freedom has resisted scholarly efforts to define its parameters. Taliaferro explores a different way of examining the tensions between the aims of religion and the needs of political communities, arguing that religious freedom is a uniquely difficult human right to uphold because it rests on two competing conceptions, human and divine. Drawing on classical natural law, Taliaferro expounds a new, practical theory of religious freedom for the modern world. By examining conceptions of law such as Sophocles’ Antigone, Maimonides’ Guide of the Perplexed, Ibn Rushd’s Middle Commentary on Aristotle’s Rhetoric, and Tertullian’s writings, The Possibility of Religious Freedom explains how expanding our notion of law to incorporate such theories can mediate conflicts of human and divine law and provide a solid foundation for religious liberty in modernity’s pluralism.”