But convictions on some matters never meant certainty on all matters. He was comfortable with what he called “inescapable ambiguity” on complicated moral matters. For Charles, abortion was such an issue. My views on abortion are more conservative than his were, but I have long kept in mind what he wrote in 1985:

There is not the slightest recognition on either side that abortion might be at the limits of our empirical and moral knowledge. The problem starts with an awesome mystery: the transformation of two soulless cells into a living human being. That leads to an insoluble empirical question: How and exactly when does that occur? On that, in turn, hangs the moral issue: What are the claims of the entity undergoing that transformation? How can we expect such a question to yield answers that are not tentative and indeterminate? So difficult a moral question should command humility, or at least a little old-fashioned tolerance.

This is a model of concision, precision and illumination.

In an age when political commentary is getting shallower and more vituperative, we will especially miss Charles’s style of writing — calm, carefully constructed arguments based on propositions and evidence, tinged with a cutting wit and wry humor but never malice.

There’s another quality of his that we will miss: intellectual independence. Charles started out his political career as a centrist Democrat yet ended up as a conservative and a fixture on Fox News. But he situated himself in a particular school within conservatism, one that is temperamentally moderate, deeply suspicious of ideology, aware of the complexity of human society, and empirical in the sense that he was constantly testing what he was saying against what was actually happening in the world and the effect it had. Charles had no interest in being a member of a political team; his goal was to better understand reality.

Political tribalism is rotting American politics; it needs more people who reject partisan zeal and can speak honestly about their own side’s blind spots and defects. Charles, alert to the maladies of the American right, was a fierce critic of Pat Buchanan in the early 1990s, when Mr. Buchanan was bringing conservative audiences to their feet with a nascent version of the ugliness and divisiveness that has come to characterize the Republican Party under President Trump. This helps explain why it was no surprise that Charles has been a harsh critic of Mr. Trump, who is an anathema to everything Charles prized. (In October 2015 Charles, in reacting to Mr. Trump’s claim that “I’m a great Christian,” told me, “Hell, I’m a better Christian than Donald Trump.” Charles, a Jew who referred to himself as a “complicated agnostic,” was right.)

“To me, loyalty to one party has never been a decision of fundamental importance,” the 20th-century political thinker Raymond Aron said. “According to the circumstances I am in agreement or disagreement with the action of a given movement or a given party.” Aron added, “Perhaps such an attitude is contrary to the morality (or immorality) of political action; it is not contrary to the obligations of the writer.” As a writer, Charles embodied the Aron ethic.

His intellect was not the most impressive thing about him; nor was his skill as a writer. His integrity was. He was a person of dignity, equanimity and personal grace. No man is a hero to his valet, the old saying goes. Charles had no valets, but he did have research assistants, many of them over the years. They speak about him with reverence.