The U.S. State Department announced last week that it will create a commission to promote human rights around the world based on “natural law and natural rights.” While it sounds harmless on the surface, the prospect has alarmed many advocates of church-state separation – and for good cause.

The problem is the term “natural law.” Although many Americans may not realize it, that’s a loaded term – code language, really. It’s often used by religious conservatives to undermine church-state separation and argue that public policy should be anchored in faith-based rationales. A better term for it is “God’s law.”

Some on the far right have long been enamored of natural law. When President George H.W. Bush nominated Clarence Thomas to the U.S. Supreme Court in 1991, controversy erupted after some of his speeches and writings surfaced in which Thomas talked about his fondness for natural law. Some critics were concerned that Thomas seemed eager to look for sources of law beyond our Constitution.

Ironically, natural law’s roots aren’t overly religious. Ancient Greek philosophers pioneered a version of it, arguing that there is an order to the universe and that human reason, when appropriately applied, is capable of understanding this order and deducing a system of ethics to govern moral behavior that is in tune with it.

The ancient Greeks were Pagan, but their musings on natural law were co-opted by Christian theologians during the Middle Ages, primarily St. Thomas Aquinas, who anchored the concept in Catholic theology. Aquinas and other church theologians argued that the source of “order” in the universe is, in fact, a monotheistic God. Because this God could be accessed through reason, it just made sense to base laws on the immutable teachings of his single, unified and catholic church (used here in the small c sense to mean “universal”).

The Protestant Reformation smashed any idea of a unified Christendom, but ultra-conservative Catholic theologians continued to promote the natural law concept, with some arguing that an application of reason would always lead one back to the Catholic Church. In the modern era, conservative thinkers have argued that natural law, which is fixed and does not evolve over time, supports the Catholic Church’s views on issues like reproduction, human sexuality and even state support of religious education. They insist that adoption of these positions is a matter of reason, not faith.

Today the natural law concept is closely tied to Robert P. George, a Princeton University professor who co-founded the National Organization for Marriage, a group that lobbied against marriage equality. In 1999, George published a series of essays defending natural law.

George, an anonymous source told ABC News, has been prominently involved in the creation of this State Department commission and is among 15 academics who have been recommended to sit on the panel.

The problem with natural law is that while it’s often dressed up in a lot of academic jargon, pseudo-philosophizing and claims to be a reason-based system, at the end of the day, its fundamental argument is this: “I’ve given this a lot of thought, and I’m convinced that my religion is true, so let’s base ours laws on it.”

Natural law advocates would assert that they’re not theocrats because they arrived at their positions through reason. Such word games provide little comfort to anyone forced to live under their oppressive theology. It’s disappointing, but not surprising, to see this kind of thin intellectual gruel informing our nation’s policy on human rights.

Those who really care about how the United States treats others would do well to admit that all history – and not to mention more than a little rational thought – proves that government-mandated religion is a poor platform for defending the rights of Christians, Jews, Muslims, Buddhists, Hindus, atheists and so on here or abroad.

(PHOTO: U.S. Secretary of State Mike Pompeo. CREDIT: State Department photo by Ron Przysucha.)