But that doesn't mean the Ten Commandments were the only foundation of what eventually became the American legal system, says Professor Benjamin Crowe, assistant professor of philosophy at the University of Utah. Roman law and the legal traditions of Germanic tribes, for example, were also important. "The Ten Commandments are central, but they're not the whole shebang."

"Word choice is really important," adds Richard Aaron, professor of law at the U. "There's absolutely no doubt that the Ten Commandments affected much of our laws, and no doubt that the Ten Commandments influenced our law — and absolutely no doubt that the Ten Commandments were not at all the foundation of our legal system."

Assertions to the contrary continue to surface. Consider, for example, the notation at the bottom of postings of the Ten Commandments once required in every public school classroom in Kentucky: "Secular application of the Ten Commandments is clearly seen in its adoption as the fundamental legal code of Western civilization and the Common Law of the United States."

The battle over displays of the Ten Commandments on government property has been waging for two centuries. On the one side are those who view the monuments as unconstitutional. On the other are those who view removal of the displays as one more proof of America's decline. "With secular humanists waging their attacks at home and the looming threat from the international radical Islam — people of faith become the line of defense," argues the Ten Commandments Commission based in Boca Raton, Fla., "and we are the watchman God has placed there. ... The Ten Commandments and what they represent are the heart of all moral code and must be defended before they are removed from society altogether." The commission is sponsoring its second annual Ten Commandments Day on Sunday, May 6.

Why not just reduce and rewrite the Ten Commandments, argues writer Gregg Easterbrook, reprising them as six imperatives about murder, adultery, stealing, bearing false witness, honoring parents and loving your neighbor as yourself. "In these words are everything we need to ground a revival of public character, without the slightest worry of constitutional challenge," he says, so it would be OK to post this revision in schools and other government buildings.

But for many Ten Commandments proponents, and indeed for many people of faith, the first four of the original 10 are crucial. For these people, says the U.'s Crowe, "the foundation for the other commandments is God, so God has to be acknowledged or the other commandments have no support."

The difference comes down to a question of where morality originates: from God or from people.