President Trump walks up the steps of Air Force One at John F. Kennedy International Airport in New York on Dec. 2. (Susan Walsh/AP)

I cannot tell you why so many White House staffers cited in Michael Wolff’s book, “Fire and Fury: Inside the Trump White House,” did not quit on principle or come forward with their concerns about the president’s fitness for office. What can I say? People are careerists; they become addicted to the power and prestige that comes with working in the White House. (And sadly, with this president, the best and brightest and most morally grounded people did not go work in the White House in the first place.)

Nevertheless, in all that we have learned over the past week and all the anecdotes about those facilitating possible obstruction of justice and enabling a non-functional president, one person managed to do the right thing. Mark Corallo, former spokesman for President Trump’s legal team, did not simply follow along. Trump and his advisers, returning home on Air Force One this past summer, busily drafted and redrafted a misleading statement to explain the infamous June 2016 meeting at Trump Tower. “Mark Corallo was instructed not to speak to the press, indeed not to even answer his phone,” according to Wolff. “Later that week, Corallo, seeing no good outcome — and privately confiding that he believed the meeting on Air Force One represented a likely obstruction of justice — quit.”

He should be an example to others in government service, really in any line of work. No job, no relationship is worth sacrificing your reputation and credibility. Shade the truth here, lie there. Soon you’ll have lost your soul. C.S. Lewis wrote about the phenomenon, the urge to stay in the “Inner Ring” that drives even good people to do bad things:

To nine out of ten of you the choice which could lead to scoundrelism will come, when it does come, in no very dramatic colours. Obviously bad men, obviously threatening or bribing, will almost certainly not appear. Over a drink, or a cup of coffee, disguised as triviality and sandwiched between two jokes, from the lips of a man, or woman, whom you have recently been getting to know rather better and whom you hope to know better still—just at the moment when you are most anxious not to appear crude, or naïf or a prig—the hint will come. It will be the hint of something which the public, the ignorant, romantic public, would never understand: something which even the outsiders in your own profession are apt to make a fuss about: but something, says your new friend, which “we”—and at the word “we” you try not to blush for mere pleasure—something “we always do.”

And you will be drawn in, if you are drawn in, not by desire for gain or ease, but simply because at that moment, when the cup was so near your lips, you cannot bear to be thrust back again into the cold outer world. … And then, if you are drawn in, next week it will be something a little further from the rules, and next year something further still, but all in the jolliest, friendliest spirit. It may end in a crash, a scandal, and penal servitude; it may end in millions, a peerage and giving the prizes at your old school. But you will be a scoundrel. … Of all the passions, the passion for the Inner Ring is most skillful in making a man who is not yet a very bad man do very bad things.

Corallo resisted that urge, did the right thing and quit. For that he may be remembered as a single honest man among a pack of scoundrels. For that we can say, well done, Mr. Corallo.