‘Dear Mr. and Mrs. DiGioia,” the letter begins. “We received a phone call from Sachs Dress Shop in New Haven today inquiring about the ‘duns’ we mailed to you. We immediately investigated the matter, and found, to our extreme chagrin, that $2 payment which you had made was mis-posted on our records to someone else’s account. This explanation is not intended as an excuse, for there can be no excuse for such errors, even though they do occur due to the tens of thousands of accounts which we handle.”

I was given a copy of this letter, dated April 10, 1957, by my friend Rosemary, who found it among her late parents’ belongings. Rosemary and I often discuss what she calls the “disappearance of civility,” the growing tendency toward thoughtless or rude behavior. Even seemingly well-brought-up people these days fail to write thank-you notes (or even emails) in response to gifts. They neglect to RSVP to invitations to parties (or even weddings). They act nasty online (or even in person) toward people who happen to disagree.

America’s approach to etiquette has always been more freewheeling than Europe’s. We never used the kinds of long-winded signoffs still customary in France: Recevez, cher Monsieur/chere Madame, l’expression de mes sentiments distingués. (Receive, dear Sir/Madam, the expression of my best regards.) We never engaged in the kind of elaborate social rituals familiar from Jane Austen’s novels. Yet a reason Austen remains popular is that she portrays a mannerly world, one that seems kinder and gentler—if not more virtuous—than our own.

Still, for all America’s laxness of protocol, certain rules have, until recently, been almost universally understood: Write a condolence note after a death. Don’t call people by their first names unless you know them well. Apologize for mistakes. Unfortunately, these basic formalities are no longer instinctual. The apology, in particular, has disappeared. The computerized nature of modern business has eroded human contact, and in a litigious culture an apology can be construed as an admission of guilt.

The novelty of that old letter to the DiGioias is that it is courteous, responsible and personally contrite, all at the same time. It immediately acknowledges blame for the mistake. It then continues:

“Furthermore, upon examining your account and related records, we realize that if, out of the tens of thousands we have, we had to choose the one hundred best accounts, your account would assuredly be one of the hundred. And yet, it was in your account that