An old friend told me that his son had been fired from his job after he published an essay online. I told him I thought this seemed illegal, and he offered to send me the essay. What I read was astounding. While I am not trained in psychology, this essay was clearly the rantings of a deeply disturbed, certainly paranoid and possibly dangerous person.

Many pages in length, it excoriated banks, businesses, politicians and society in general for conspiring against “ordinary people.” While not directly calling for civil unrest, it urged readers to take matters into their own hands. It was clear to me why a company would not want the author of this piece as an employee.

My problem is what to say, if anything, to my friend. He did not signal to me that he found this essay disturbing, though he may have been holding back, waiting for my opinion. Do I have an ethical obligation to tell him that I think his son may have a problem? I can’t be sure it’s true, and it could be damaging to our relationship. On the other hand, I feel that my silence does him, and possibly his son, a disservice. P. L., New Jersey

Not having seen the essay, I can’t say whether I agree with your diagnosis. Maybe he’s simply splicing Michael Moore onto Sean Hannity. But if your friend’s son has a psychiatric problem, as you suppose, his father is in a better position to do something about it than most people. The fact that the boy’s father doesn’t see an obvious problem does make me wonder whether you’re right — though, as you say, he may just be waiting for you to confirm his suspicions. Facing up to mental illness in your own family is hard. At least if you say what you think, it’ll be your friend’s choice what to make of it, and what to do about it. And if the son turns out to be as disturbed as you suspect and creates further trouble, you’ll regret it if you said nothing when you had the chance.

Two close friends, whose values I generally admire, recently sold their businesses and retired. Over the years, I became aware that both friends regularly took cash receipts “off the top” and did not report them. While I always questioned the fairness and equity of such a move (the illegality is prima facie), I never said anything about it. Recently, my friend told me that they both have a safe at home with enough cash to live on for several years, and that it was set aside from their businesses in the same manner. These are close friends, who, as I said, are otherwise principled people. I am troubled about this. Is there anything that I should do, other than mind my own business? Name Withheld

Society is a vast scheme of cooperation that depends on the compliance of its members to secure its benefits. Not doing your fair share is a moral wrong. But what’s a bystander like you to do about it?

Scriptural traditions often enshrine sound moral insights, and there’s a long Islamic tradition, based on passages in the Quran, about “commanding right and forbidding wrong,” that makes good Muslims responsible for keeping others on the right path with “the hand, the tongue or the heart.” Stopping your friends with the hand here would involve reporting them to the authorities. At this late date, though, the main effect of doing so would be to expose these people to prison time and possibly steep financial penalties — and yourself to opprobrium from their friends and family. What’s more, your friends took you into their confidence on the assumption that you would keep that confidence, and your friendship makes that assumption a reasonable one.