Getty; Paul Spella / The Atlantic

Many observers breathed a sigh of relief when Bill Barr was confirmed as attorney general. Here was a respected professional who had served in the post once before in an honorable administration. Now, just a year and a half later, what a disappointment he has proved. The man cannot be trusted.

Think of the intentionally misleading account he gave of the Mueller report, at a time when the public and Congress had only Barr’s word to go by. Or the brief he allowed his Justice Department to file with the Supreme Court in the case about including a citizenship question on the 2020 census, whose rationale the Court later characterized as “contrived” and “pretextual.” Or his false account of the use of armed forces to clear Lafayette Square for the president’s photo op. Or his statement that U.S. Attorney Geoffrey Berman asked to step down, when Berman had done no such thing. And now we have damning testimony this week about the politicization of the Department of Justice in the prosecution of the Trump ally Roger Stone.

The attorney general is entitled to his opinion on the policies underlying these matters, and to argue forcefully for them. But as a lawyer, as a high official, as an officer of the court, he must not misrepresent the facts or the authorities. Americans need not agree with the attorney general’s arguments or conclusions, but they must have absolute confidence that he will not try to deceive them.

How did a man with a good reputation allow himself to mislead time and time again? Barr proclaims himself—as in recent speeches to the Federalist Society and at Notre Dame—a man of deep moral principles and is proud to espouse stern, rigorous Roman Catholic convictions. There are, of course, strong differences of opinion on the morality of abortion, LGBTQ rights, and the separation of Church and state generally. Some Christian groups have embraced all of these; to others they are anathema and symptoms of moral degeneracy.

But on one moral principle, all must come together: the supreme value of truth. Satan, Jesus says in the Gospel of John, is the father of lies. As Saint Augustine explains in De Mendacio, the Ninth Commandment is not limited to injuring another by false testimony in a court proceeding, but extends to any communication intended to deceive. In his Divine Comedy, Dante consigns deceivers, liars, and falsifiers to the eighth circle of hell—the circle of fraud.

There is a reason for this. Truthfulness is a basic condition for trust between people. In the Genesis account, God caused the builders of the Tower of Babel to speak in different tongues so they could not understand one another and could not collaborate in even the simplest tasks. If people cannot believe one another, communication breaks down, trust becomes impossible, and society corrodes.

How did Barr decline to the level of a purveyor of mistruths? We guess it was by his determination to serve faithfully a man who is so careless of the truth that he does not even try to be consistent from one statement to the next, from one day to the next. Barr has proclaimed as a foundational principle the sovereignty of executive power. The executive he has chosen to serve is uniquely untruthful, reckless, and vain. Perhaps Barr’s loyal service to that principle entails loyal service to Trump—the only executive we have—and not only to his ends, but to his means. Holding a similar post as Barr in Tudor England, Sir Thomas More recognized the fallacy of this position, defied his king, and was executed. He was later canonized for his faith.

Proximity to such a person as Trump is toxic. Rex Tillerson, James Mattis, John Kelly, and H. R. McMaster all tried to practice moral social distancing from this morally diseased president, but broke with him because their integrity came before their loyalty to the person. Barr has committed to Trump warts and all, but the warts are in fact suppurating sores, and he is now fatally infected.

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