Greenawalt’s volume is the second in what amounts to a comprehensive summa of American law and practice under the First Amendment’s religion clauses. Together the volumes provide close to a thousand pages of intensive, methodical analysis of virtually every contemporary issue that arises under those clauses. The comprehensiveness of Greenawalt’s treatment makes for a book that, though more than a conventional treatise, should be valuable for use in the way treatises are employed. This is not the sort of book that many readers will want to sit down and read cover-to-cover. But for a careful, fair-minded analysis of the cases and arguments with respect to virtually any establishment controversy that a judge or scholar may be investigating, one could hardly do better than to consult Greenawalt’s treatment. And his relevant chapters ought to be mandatory reading for any student who wants to write a seminar paper or law review comment on a religion clause topic.