WASHINGTON — Washington. -- Within days of Clarence Thomas' nomination to the Supreme Court, you could take your pick of half a dozen charges against him. He was, we were told, an Uncle Tom in judicial robes, turning ungratefully against the same affirmative action that made him what he is. The hoary claim was revived that any office holder with Catholic convictions would become the pope's puppet. Somebody turned up speeches in which Mr. Thomas had praised an anti-Semitic demagogue. Others recalled his admission that he puffed pot in college.
All these were debated back and forth in print and on television. But one charge, though repeated, seemed to hang in midair, little debated and probably little understood. It was that Clarence Thomas based his legal philosophy on natural law.
The charge reflected less on Clarence Thomas than on our own unhappy times. Until a generation or two ago, the American legal profession, including the judiciary, took a jurisprudence of natural law for granted. But what is it? William Blackstone, whose writings were standard texts for law students at the time this nation was founded, summed it up:
''The law of nature . . . dictated by God himself . . . is binding . . . in all countries and at all times; no human laws are of any validity if contrary to this; and such of them as are valid derive all force and all their authority . . . from this original.'' For instance, it is always wrong to kill or steal.
In the Declaration of Independence, the Founding Fathers showed that they knew their Blackstone, and their natural law. They declared the American people were taking that place among nations ''to which the Laws of Nature and of Nature's God entitle them.''
Now there's the sticking point for the secularists who constitute the mainstream of American legal thought. A jurisprudence of natural law, in its usual formulation, traces the authority of civil law through the law of natural justice to the author of justice, God himself. For our secular humanist Establishment, for the champions of the ''wall of separation'' between religion and civil society, this verges on obscene.
What they offer in its stead is the prevailing doctrine in our law schools, a theory called legal positivism. Law is simply the will of the lawmaker. There is no such thing as justice; there's merely a balance between competing interests.
In the words of the influential theorist of legal positivism, the Austrian-born jurist Hans Kelsen, law is only ''a system of coercion-imposing norms which are laid down by human acts in accordance with a constitution.'' Laws have nothing to do with morality, according to Kelsen: ''Any content whatsoever can be legal: there is no human behavior which could not function as the content of a legal norm.''
It would be hard to exaggerate Kelsen's impact on the law in Europe and America. He taught at Harvard and the University of California, Berkeley, where his ideas remain part of the intellectual ferment, and he also wrote the Austrian constitution adopted after the fall of the Hapsburg Empire. More significantly, the legal positivism that he and other theorists propounded gave theoretical undergirding to the Nazi regime.
Here, a little-known drama arises. Gustav Radbruch, a brilliant courtroom lawyer, legal philosopher and minister of justice in the Weimar Republic, had been perhaps the foremost legal figure in Germany between the wars. His prestige alone was capable of legitimizing legal positivism, the philosophy he preached. However, seeing the fruits of legal positivism in the Nazi system of law, he began rethinking his jurisprudence. When at last he was freed from the silence the Nazis had imposed on him, Radbruch dramatically renounced legal positivism and became a widely heard champion of natural law.
He was not heard in the United States, though. Here the lessons of Nazism have apparently been little learned. The great tradition of natural-law jurisprudence is spurned, and a nominee to the Supreme Court is reviled for embracing it.
The history of natural-law jurisprudence runs from Cicero, who first articulated it, through Bracton, Coke and Blackstone -- some of the greatest names in the law. It is a long, constructive and noble history. The history of legal positivism runs from Machiavelli through Nazism to current theorists whose names we pass over in charity. It is a short, brutish and nasty history.
In embracing a jurisprudence of natural law, Clarence Thomas puts himself in the best tradition of ancient Rome, of the great jurists, both Catholic and Protestant, of our Founding Fathers. He rejects a jurisprudence of injustice. For that his competence to sit on our highest court is challenged.
Patrick Riley is director for governmental affairs of the Catholic League for Religious and Civil Rights. He wrote this commentary for the Los Angeles Times.