(FORTUNE Magazine) – Our eye was caught by an item in the November 15 Wall Street Journal about a tax delinquent in Pennsylvania. The Journal said the nonfiler in question, a businessman named Ernest R. Lilley Jr., had been defended in tax court by a psychiatrist and a psychologist who testified gravely -- at least we envision them as not giggling -- that Lilley suffers from ''a disorder that blocks only his ability to file federal returns while he otherwise functions normally.'' We have long puzzled over the psychology of certain people who do not file tax returns. Just to be clear about what is and isn't puzzling: We are not talking about ''second economy'' sharpers who calculate that they won't be caught, or about ideologues who refuse to file because they oppose (say) defense spending. Those cases are easy. What we cannot seem to get a handle on is a peculiarly self-destructive type: the nonfiler with a high profile and every reason to believe delinquency spells big trouble. Before turning to David N. Dinkins, New York's new mayor, we mention a few other middle-aged delinquents. James M. Landis was an adviser to Presidents Roosevelt and Kennedy, a dean of the Harvard law school, and a chairman of the Securities and Exchange Commission -- yet he failed to file tax returns from - 1956 through 1960. He was prosecuted and sentenced to 30 days in prison. In July 1964, he was found dead in his swimming pool. Equally counterintuitive was the case of Edmund Wilson, for years the preeminent American man of letters. Wilson combined awesome erudition with a plain-spoken style bespeaking reasonableness and common sense. He wrote knowledgeably about literature, ancient history (The Scrolls From the Dead Sea), politics, and (in his masterful To the Finland Station) the theory of the state. But he seems not to have understood that the state in America takes income taxes seriously. After failing to file returns for 1946 through 1955, Wilson was brought to the edge of poverty by penalty payments; to be sure, he escaped jail. The saga of Anthony L. Conrad, who rose to be chairman and CEO of RCA, was also amazing. Your correspondent knew Conrad slightly and had him sized up as smart and tough-minded. Possibly contributing to both impressions was his leading role in the 1975 coup d'etat that led to the ouster of his predecessor, Robert Sarnoff, while Bobby was out of the country. But ten months later, Conrad himself was out, undone by the stunning revelation that he had filed no tax returns for at least five years. Data compiled by the ever odious but in this case presumably accurate New York State Department of Taxation and Finance tell us that nonfiling among highflying lawyers is rampant. Astounding lead from a New York Times story earlier this year: ''Almost 10% of the partners in law firms surveyed by New York State failed to file state tax returns for at least one of the last three years, the state . . . said today.'' We find ourselves yearning to be compassionate toward New York nonfilers, as they are looking at scandalously high income-tax rates. (Top marginal rates in the state are 7.875%; in New York City, another 3.5%; and if you are a self- employed professional in the city, still another 4% on your ''unincorporated business'' earnings.) Still, we have trouble explaining all those characters who are masterful in building high-powered careers and then inexplicably self-destruct in this corner of their lives. What screws are loose in their heads? This brings us, serpentinely, to the Dinkins case. As tout le monde now knows, the man just elected mayor of New York is among the lawyers with a delinquent track record: He failed to file city, state, or federal returns for 1969 through 1972 (years when he was a city official but derived most of his income from a private law practice). Dinkins's failure seemed especially egregious, as Dave had spent his life toiling for the Jesse James gang that brought New York its tax-rate preeminence. The big story about his election was, of course, New Yorkers' first-time- ever elevation of a black to the mayoralty. Okay, that's news. But it is also news that New Yorkers would embrace a politician of any race for behavior that in other folks leads to disgrace and signifies irrationality.