Today the Supreme Court hears oral arguments in McCreary Co. v. ACLU, a case concerning whether the Ten Commandments may be posted in a courthouse as part of a display of dozens of documents illustrating the foundations of American law. The case is important for several reasons: In addition to settling the question about the constitutionality of these displays across the country, the Court has agreed to reconsider the controversial test it uses in deciding whether government action violates the First Amendment's prohibition against religious establishments. But perhaps most important, the case vividly demonstrates the problem with willful judges, and...