In January, the Holy See warned that “cultural relativism,” which denies the existence of absolute truths, threatens to undercut contemporary democracies.

In April, American commentators proved him right by loudly denouncing Sen. Rick Santorum, R-Pa., for drawing moral lines on the issue of sodomy.

Santorum sparked a wave of tut-tutting when he said, “And if the Supreme Court says that you have the right to consensual sex within your home, then you have the right to bigamy, you have the right to polygamy, you have the right to incest, you have the right to adultery. You have the right to anything.”

The New York Times was quick with a sarcastic spin. Its April 22 editorial said: “Hear ye, hear ye: Sen. Rick Santorum feels obliged to offer gratuitous guidance to the Supreme Court in the form of an ad hoc, highly unlearned ruling that equates homosexuality with bigamy, polygamy, incest and adultery.”

Sadly, that misses the point. Santorum's argument is about the codification of moral relativism into America's laws, and that The New York Times missed the point only shows how right he is.

Cardinal Joseph Ratzinger's Congregation for the Doctrine of the Faith knew exactly how such a statement would be received.

Its “Doctrinal Note on Some Questions Regarding the Participation of Catholics in Political Life,” which debuted Jan.16, is worth quoting at length.

It says that “a kind of cultural relativism exists today,” adding, “it is not unusual to hear the opinion expressed in the public sphere that such [relativism] is the very condition for democracy.”

As a result, it adds, “lawmakers maintain that they are respecting this freedom of choice by enacting laws which ignore the principles of natural ethics and yield to ephemeral cultural and moral trends, as if every possible outlook on life were of equal value.”

It concludes that “political freedom is not — and cannot be — based upon the relativistic idea that all conceptions of the human person's good have the same value and truth, but rather, on the fact that politics are concerned with very concrete realizations of the true human and social good in given historical, geographic, economic, technological and cultural contexts.”

But you don't need to look to the Catholic faith to find justification for Santorum's words.

You need only look to the 1986 decision of the Supreme Court in Bowers v. Hardwick.Justice Byron White, writing for the 5-4 majority of the court, said that the court found “no connection between family, marriage or procreation on the one hand and homosexual activity on the other.” The court found nothing in the Constitution that “would extend a fundamental right to homosexuals to engage in acts of consensual sodomy.”

He pointed out that, “Proscriptions against [sodomy] have ancient roots. Sodomy was a criminal offense at common law and was forbidden by the laws of the original 13 states when they ratified the Bill of Rights. In 1868, when the 14th Amendment was “ratified, all but five of the 37 States in the Union had criminal sodomy laws.”

White even spoke in language very much like what would later be used by the Vatican when he gave a sharp rebuke to modern-day slogans about how “you can't legislate morality.”

He wrote, “The law, however, is constantly based on notions of morality, and if all laws representing essentially moral choices are to be invalidated under the Due Process Clause, the courts will be very busy indeed.”

The Supreme Court then saw what Santorum sees now. Moral relativism is tempting. It means you don't have to decide what's right or wrong. But, ultimately, it only backfires in a dangerous way.

If the law refuses to distinguish right from wrong in sexual matters, society will soon find out that the damage won't be confined to “partners” in the privacy of their bedrooms.