Abner Green reviews Martha Nussbaum's recent book, Liberty of Conscience: In Defense of America's Tradition of Religious Equality, and in doing so attempts to illuminate the foundations of religious equality in America.  Greene also compares Nussbaum's view of equality in the Religion Clauses to the views presented by Christopher Eisgruber and Lawrence Sager in Religious Freedom and the Constitution, and Brian Barry in Culture and Equality: An Egalitarian Critique of Multiculturalism.  Greene also considers the broader question of how we grant religious exemptions from otherwise applicable law; he explores how both Nussbaum and Eisgruber and Sager characterize such exemptions.