Although many people believe that Samuel Johnson said "The true measure of a man is how he treats someone who can do him absolutely no good," there is no concrete evidence that he ever said it or wrote it. It doesn't appear in his works or letters, nor in any of the biographies of him from the 18th century. Nor does it appear in "The Beauties of Johnson," a collection of his sayings.

Admittedly, it does appear on many Internet pages, but none of them say where it can be found. And just as many pages credit advice columnist Ann Landers for having said it. (In fact, the quotation web site Brainyquote credits it to both Landers and Johnson on separate pages, without mentioning on either page that there is any question about who said it. And they don't have a source for it in either case. It would be nice if, on the page where they attribute it to Johnson, they noted that it's also attributed to Landers, and vice versa. As it is, people come away from each page having no idea that there is any question on the matter.) It's not a good sign that there is wide disagreement about who said something, and it's a worse sign when the quotation can't be found.

Here's a hypothesis for research. Perhaps Landers was paraphrasing something Johnson did say in one of her columns, and said she was paraphrasing Johnson; and while some readers recognized the paraphrase was not actually a Johnson quotation, others were confused. (A good candidate for what she might have paraphrased might be Johnson's "A decent provision for the poor is the true test of civilization", or perhaps one of his comments that it is the servants in a household who know someone best.)

But there is an additional problem I've encountered... I can't even find this quotation in print as being attributed to Ann Landers. Quotation encyclopedias I've looked at don't have it. And I can't find any of Landers' books. So please keep your eyes open, and maybe together we can answer this.