Robert Merrihew Adams in Notre Dame Philosophical Reviews:
“Why tolerate religion?” The question is raised by someone who thinks there is something wrong about religion as such. To tolerate, Brian Leiter emphasizes, is to “put up” with beliefs or practices that one regards as “wrong, mistaken, or undesirable” (p. 8). His paradigm case of principled tolerance is one in which a “dominant group has the means at its disposal to effectively and reliably change or end [a] disfavored group's beliefs or practices, and yet . . . acknowledges that there are moral or epistemic reasons . . . to permit the disfavored group to keep on believing and doing what it does” (p. 13). Forcibly changing or ending religious belief has commonly been extremely difficult or impossible to achieve by any means short of total extermination or banishment of the disfavored group, as history shows, and is therefore a really scary project. With his stated paradigm in mind, we might think that Leiter's statement that “the contemporary problem, at least in the post-Enlightenment secular nations, . . . is why the state should tolerate religion as such at all” (pp. 14-15), would be ominous indeed if it were an accurate reading of political reality.
Fortunately and sensibly, Leiter does not hold that “the protection against intolerance [is] exhausted by a mere prohibition on annihilation or imprisonment of those with the disfavored beliefs and practices” (p. 109). The book's thoughtful and interestingly argued discussions of particular legal issues about tolerance (found mainly in the last of its five chapters) are generally not focused on questions of forcibly ending or fundamentally changing religious beliefs and practices, except for the most blatantly intolerable practices. Rather they concern public policies that (intentionally or unintentionally) limit the scope for exercise of the practices, or more generally disadvantage religious beliefs and practices or their adherents.
More here.