Of Vienna's mixed legacy to us Freud, Strauss waltzes, logical positivism, all mingled with a little crackpottery -- at least one gift stands out as a life- enhancing plus.

Felix Frankfurter was born there Nov. 15, 1882, a century ago this week.

When his friend and patron (and fellow centenarian) Franklin Roosevelt was enjoying a gilded boyhood in Hyde Park, N.Y., Frankfurter was a German-speaking lad in the land of the Hapsburgs. His education in English began only at the age of 12, when his parents brought him to New York.

"Marginality" -- coming from the fringes -- often explains the deepest and richest political attachments. America and its heritage of Anglo-American law were such attachments for Felix Frankfurter. Voluntarily affirmed, they were elective affinities and the stronger for being so.

Yet something Viennese lingered in Frankfurter's bubbling personality, his talent for making friends and brightening gray days. He had, recalls Isaiah Berlin, "an unrivaled power of liberation of human beings imprisoned beneath any icy crust of custom or gloom or social terror."

Frankfurter was already a distinguished man -- scholar, teacher, public servant, advocate -- before Roosevelt appointed him to the Supreme Court in 1939: one of the first crop of "Roosevelt justices." (He was to serve there until 1962 -- three years before his death.)

He had already been heard from. As a young law professor he had been scandalized by the Sacco- Vanzetti case. A noxious odor of class prejudice, of judicial lynching, hung over the conviction of two Italian immigrant anarchists in a notorious robbery-murder of the 1920s. Frankfurter fought bravely but vainly for retrial. Whether or not he was right on the question of guilt, his writings on the case brought to public view his lofty vision of the law as a neutral force, above all taint of class, party or personal predilection.

The same vision, as well as personal loyalty, made him side with FDR against the Supreme Court in the mid-1930s. With most New Dealers, he suspected the "four horsemen" of the court of bootlegging personal economic views into the Constitution.

As a justice, his name is forever associated with "judicial restraint," the doctrine of his mentors, Holmes and Brandeis. For Frankfurter, it worked both ways. If judging was neutral for the powerful, it must sometimes be injuriously neutral for the weak as well. His dogged consistency on the point often distressed his friends.

Never more so, perhaps, than in the second "flag-salute" case of 1943, when he persisted in supporting the view that a state could, indeed, require patriotic gestures of the children of religious dissenters.

His explanation remains poignant, after 40 years: "One who belongs to the most vilified and persecuted minority in history is not likely to be insensible to the freedoms guaranteed by our Constitution. . . . But as judges we are neither Jew nor Gentile, neither Catholic nor agnostic."

In his classic sketch of Holmes, he later wrote that judging calls "for rare intellectual disinterestedness and penetration, lest limitation in personal experience and imagination operate as limitations of the Constitution."

Frankfurter understood that personal disinterestedness is especially critical in a system such as ours where judges have unique power to check democratic judgments.

Frankfurter's judicial bent is best epitomized in a story. Friends had taken him, late in life, to see Robert Bolt's great play about Sir Thomas More, "A Man for All Seasons." In one scene, More's son- in-law, Roper, indignantly declares that he would cut down every law in England to get at the Devil.

"Oh," More responds. "And when the last law was down, and the Devil turned round on you -- where would you hide, Roper, the laws all being flat? This country's planted thick with laws. . . . Man's laws, not God's -- and if you cut them down . . . then d'you really think you could stand upright in the winds that would blow then? Yes, I'd give the Devil benefit of law, for my own safety's sake."

As More's lines were spoken, Frankfurter, edging forward in his seat, enthusiastically whispered: "That's it! That's it!" What was this "it" that Frankfurter heard in More's lines and cherished in a great American life that began a century ago this week?

Just this: the law will protect the good man and the righteous cause only if it also extends an even hand to the evil and iniquitous as well. That lesson, hard to grasp and still harder for most of us to embrace, is the heart of the rule of law. It had no better friend in a long and fragile history than Felix Frankfurter.