Absolute religious freedom is impossible, argues Winnifred Fallers Sullivan in her 2007 The Impossibility of Religious Freedom , an analysis of Warner v. Boca Raton , which led to the banning of interreligious religious symbols from a cemetery in the Florida town.

Religious freedom always founders on the issue of definition. In every legal case involving religion, she argues, “a court or a legislature or an administrative official must make a determination as to whether the religious practice in question is legally religious. In other words, in order to enforce laws guaranteeing religious freedom you must first have religion.” Decisions cannot be made unless one “draw[s] a line about what counts as religion and what does not (pp. 1-2). But once the state draws a line around religion and excludes what is outside, the state has departed from the practice of absolute religious freedom.