Irving Kristol, who passed away last week at the age of 89, was like everyone's favorite uncle -- if the uncle were a transformative intellectual of empyrean stature. He was both a warm and approachable human being and a penetrating social critic. He was, in a very American way, a practical man, and his approach to ideas was always firmly and refreshingly reality-based.

Irving Kristol was born in New York in 1920, so it was inevitable that he would become, for a short time at least, a socialist. But even as a young socialist, Kristol was skeptical about the principal animating sentiment of the left: a belief in man's perfectibility. As early as 1944, Kristol wrote of his preference for "moral realism," which "foresees no new virtues" and is "interested in human beings as it finds them, content with the possibilities and limitations that are always with us." It was a Madisonian frame of mind and it would take him by degrees to the right.

Though the term "neoconservative" has come to be associated with a muscular foreign policy (when it is not a thinly veiled codeword for Jew), it began in the 1960s as a disparaging term for those liberals, led by Kristol and a few others, who were bent on doing something that made other liberals acutely uncomfortable: test whether their theories worked in the real world.

Through his quarterly journal, set ital The Public Interest end ital, as well as his indispensable column in the Wall Street Journal, Kristol turned his analytical attention to the programs of the Great Society. Did urban redevelopment really improve the lot of the poor? Did deinstitutionalization of the mentally ill work? Did welfare programs have unintended consequences? If these questions now seem obvious, it is because Kristol offered an early and perspicacious critique that has since become conventional wisdom. "The problem with our current welfare programs," he wrote decades ago, "is not that they are costly -- which they are -- but that they have such perverse consequences for the people they are supposed to benefit."

In issue after issue, set ital The Public Interest end ital catalogued the failure of Great Society programs to achieve their goals and itemized the programs' unintended and often baleful consequences. Empiricists who read Kristol tended to become neoconservatives and eventually unprefixed conservatives. Ideologues were of course unmoved, and some of Kristol's most trenchant commentary concerned them. In 1972, Kristol wrote: "'All bad poetry springs from genuine feeling,' wrote Oscar Wilde, and I would like to suggest that the same can be said for bad politics . ... It seems to me that the politics of liberal reform, in recent years, shows many of the same characteristics as amateur poetry. It has been more concerned with the kind of symbolic action that gratifies the passions of the reformer rather than with the efficacy of the reforms themselves. Indeed, the outstanding characteristic of what we call 'the New Politics' is precisely its insistence on the overwhelming importance of revealing, in the public realm, one's intense feelings -- we must 'care,' we must 'be concerned,' we must be 'committed.' Unsurprisingly, this goes along with an immense indifference to consequences, to positive results or the lack thereof."

Because he actually did care about ordinary people and their welfare, Kristol became one of capitalism's great apologists. Capitalism had eased more misery and engendered more comfort than any other system in world history, he pointed out (and he knew his world history). But starting in the 1960s, Kristol became something else that discomfited liberals even more than a capitalist -- a cultural conservative. As he wrote in "My Cold War," a 1993 recap of his intellectual journey from left to right: "But what began to concern me more and more were the clear signs of rot and decadence germinating within American society -- a rot and decadence that was no longer the consequence of liberalism but was the actual agenda of contemporary liberalism. And the more contemporary, the more candid and radical was this agenda." While he believed, as he said on another occasion, that "This cultural nihilism will have, in the short term, only a limited political effect -- short of a massive, enduring economic crisis. The reason ... is that a bourgeois, property-owning democracy tends to breed its own antibodies. These antibodies immunize it, in large degree, against the lunacies of its intellectuals and artists." Nevertheless, he warned, combating the cultural decay -- a war on spiritual poverty -- was even more important than winning the other Cold War.

Irving Kristol often praised the common sense of ordinary people and disdained the vanity and foolishness of intellectuals. He was that rarest of blends: a sparkling intellectual who was grounded in common sense and experience. It was a world-shaking combination.