WASHINGTON—Occasionally, I ask myself what the ideal column is. I don’t have a definitive answer—only memories of great columnists.

The greatest column of the 20th century was by British journalist Bernard Levin in The Times of London predicting—in September 1977—that communism would fall in 1989. I was in London in 1992, when he elegantly drew attention to his old article.

He foresaw that communism’s demise would take place when men who had lost faith in the system, yet were moving up the ranks, had reached the top. He based this on his observations of the failed attempts of Hungarian communists (1956) and Czech communists (1968) to break away from Moscow, the obvious pressures that religion and nationality—two forces suppressed but not eliminated by the Soviets—brought to bear on that regime, and on the belief that human nature can only take so many lies.

“There will be no gunfire in the streets,” he wrote, “no barricades ... or mass defections among the military. But one day soon, some new faces will appear in the Politburo—I am sure they have already appeared in municipal and even regional administrative authorities. ... Until one day they will look at each other and realize that there is no longer any need for concealment of the truth in their hearts.”

He suggested a date—July 14, 1989—but the emphasis was on the idea that it would happen soon.

A great columnist doesn’t get predictions right—unless they are in the wrong business. What is astonishing is not Levin’s capacity to see the future but the present. Three things—knowledge of history, observation of the subtle relation between institutions and social realities, and intellectual integrity—helped him read between the lines of Soviet life in 1977.

Do those ingredients make great columnists? No, but every great columnist has them. You can write wonderful columns without them—but not the best. The greatest columnists add a touch of genius, sometimes in the form of a surprising intuition or corrosive humor; their columns, like good wine, continue to tickle the taste buds after the glass is empty.

My choice for greatest American columnist of the 20th century would be H.L. Mencken, who wrote for The Baltimore Sun in the early part of the century and, later, in The American Mercury. He was an individualist who enjoyed “heaving the dead cat into the temple.” He was distrustful of all governments, even those he might sympathize with: “If it be aristocratic in organization, then it seeks to protect the man who is superior only in law against the man who is superior in fact; if it be democratic, then it seeks to protect the man who is inferior in every way against both.”

He was not perfect. He made comments that would not be acceptable today and his belief in individuals rather than groups led him to criticize even minorities, which left him open to latter-day charges of racism, although he reserved his worst epithets for mainstream society. He often got it right because he learned, observed and spoke the truth—with incendiary wit.

In the Spanish language, the greatest columnist of the 20th century was Spain’s Jose Ortega y Gasset, who said that “clarity is the courtesy of the philosopher” (he was a philosopher himself). He had little humor of the obvious kind, but provided his countrymen with the truth when so many of them failed to see it, both when the republic degenerated into left-wing totalitarian tendencies in the 1930s and during the reign of fascism later on.

In Italy, Indro Montanelli was probably the greatest. He was an anti-communist liberal (in the European, not the American, sense of the word). He had the guts to oppose Silvio Berlusconi when the tycoon went into politics, even though Montanelli worked for Il Giornale, a Berlusconi-owned paper, because the columnist realized his boss would not differentiate between his interests and the state’s.

Another superb columnist was French author Jean-Francois Revel—intellectual heir to Raymond Aron—who wrote for L’Express and later for Le Point. He believed a good column should limit itself to one idea. This was a Frenchman talking—a perfect rationalist. But, yes, if the column is argumentative—rather than sensual or impressionistic—it had better shoot in one direction.

Who will write the greatest column of the 21st century? It won’t be Pat Buchanan predicting the demise of the West because of immigration. But perhaps in September 2077, a blogger will predict that on July 14, 2089, a first-generation Mexican immigrant will be president of the United States—and perhaps a namesake for Pat Buchanan will vote for her.