Among the more unremarked achievements of the late Arthur Schlesinger Jr. is how little enmity he inspired. Excluding the ideologically obsessed sourpuss Norman Podhoretz and the young philistine Jonah Goldberg, nary a disparaging word has been heard about this most combative of liberal lions since his recent death. This is surprising because, leaving aside politics, for the balance of his remarkable sixty-plus years as a historian, journalist, pundit, film critic, presidential adviser and marathon martini drinker, Schlesinger consistently refused to recognize the boundaries that most intellectuals accept as a matter of course. As a result of this refusal, he led one of the most consequential lives of the American twentieth century.

Nothing about Arthur Schlesinger Jr. was fashionable (including, especially, those goofy bow ties). When he first came to prominence as a historian, he challenged the emerging power of the “consensus school” historians by refashioning the previous era’s “progressive” interpretation of American history, which focused almost exclusively on class and economic division, to allow for the importance of ideas and ideology in shaping a nation’s political life. Although his work was unapologetically “presentist” in orientation–the historian “wrote the way he voted” went the quip–almost all of it remains standing today, which is an astounding accomplishment, given how much history has since been uncovered. Schlesinger’s excavations of the ages of Jackson and Roosevelt remain required reading. And for all his emotional commitments and personal connections to Camelot, his magisterial studies of the careers of President Kennedy and Robert Kennedy hold up almost as well. (I don’t think anyone has improved on his epigram, “John Kennedy was a realist brilliantly disguised as a romantic, Robert Kennedy, a romantic stubbornly disguised as a realist.”)

Writing on the website of the History News Network, presidential historian Alonzo Hamby expresses the common regret that Arthur “became so enmeshed with the Kennedys, if only because the entanglement diverted him from his historical vocation and left him open to attack as a court historian.” But who wants to live life so as to avoid attack? Schlesinger’s sideline as America’s “quintessential ‘engaged’ intellectual,” as historian Kevin Mattson has called him, was clearly one he relished, but he never insisted it was for everyone. Indeed, he admired his friend Richard Hofstadter, a historian who purposely retained his critical distance from politics and, while working in the Kennedy White House, praised Murray Kempton for his tough tack toward power, thereby offering an “antidote to the danger that those with influence might take themselves too seriously.”

Schlesinger never changed his stripes as a liberal anti-Communist and New Deal Democrat, and his most controversial arguments feel awfully prescient today. While The New Republic and The Nation were still strangely schizoid about Stalin–though more supportive than not–Schlesinger issued warning after warning to the American left about the dangers posed by the US Communist Party. Three years before publishing The Vital Center (1949), writing in Life magazine, he compared Communists to Mormons or Jehovah’s Witnesses, who carry “their infection of intrigue and deceit wherever they go.” With their systematic mendacity and duplicity, “Communists are engaged in a massive attack on the moral fabric of the American left.” Even so, Schlesinger was able to make crucial distinctions. He rejected the notion that US Communists posed a threat to the Republic. “The Communist party is no menace to the right in the U.S. It is a great help to the right because of its success in dividing and neutralizing the left. It is to the American left that Communism presents the most serious danger.”

But of course liberal anti-Communists did not exactly cover themselves in glory when it came to defending free expression in the face of McCarthyist blacklists. The last time I had lunch with Arthur–at a fancy East Side bistro he favored–I asked him if he felt anti-Communist liberals had allowed their hatred of Stalin and Soviet totalitarianism to overshadow their commitment to civil liberties at home. But like Edith Piaf, Arthur regretted rien. “We had a Two Joe policy of opposition back then,” he insisted. “We were against Stalin and against McCarthy.” True, I tried to argue, but was the balance the best one? After all, while Stalin was one of history’s worst mass murderers, he turns out to have presented no genuine military threat to the United States or even, as it turns out, Western Europe. Joe McCarthy untrammeled, on the other hand, did more damage than anyone to America’s democratic institutions until George W. Bush. Arthur shrugged and ordered another martini.

Schlesinger’s more recent intraleft controversy arose when he made another prescient argument about a danger on the left: this was his short 1991 book on Afrocentrism and multiculturalism, The Disuniting of America. Although it was one of his slighter efforts, intellectually, Arthur recognized then, as few did, that by making a fetish of racial and ethnic divisions, the left was playing into the same divide-and-conquer politics that the corporate elite has always used against America’s working classes.

In his final years, Schlesinger was revitalized by his anger at what the right was doing to America. He warned of “ominous preparations for and dark rumors of a preventive war against Iran” and complained of leaders who “do not know enough history, and they duplicated the stupidity of the Vietnam War” in Iraq. He dissociated himself from the liberal hawks and criticized those who sought to replace Communism with “terrorism” as America’s all-purpose enemy. He was too good a historian to allow the neocons’ hysterics to undermine the lessons he had spent so much of the past century learning and teaching. “History is the best antidote to illusions of omnipotence and omniscience,” he wrote in one of his final published articles. “It should forever remind us of the limitations of our passing perspectives. It should strengthen us to resist the pressure to convert momentary interests into moral absolutes.”