The potential for outrage at unfair and unjustified criticism of my uncle, Cardinal John O'Connor, the archbishop of New York, is enormous. I have heard the most ludicrous charges hurled at him. After a while one learns to ignore even the worst invective. However, Colman McCarthy's column on him {Style, Jan. 10} was too much.

Mr. McCarthy's assertion that Cardinal O'Connor is indifferent to the tragedy of the AIDS epidemic continues a tradition of ill-informed and inaccurate commentary. Whether one agrees with the recent U.S. Catholic Conference statement on AIDS or not, it is clear that the unskillful and confusing phrasing caused several members of the bishops' conference -- not only Cardinal O'Connor, and not a few rank-and-file Catholics -- to take issue with substantive passages. For Mr. McCarthy to translate this into a belief that Cardinal O'Connor lacks compassion for the suffering of AIDS patients is twisted logic.

It is possible to quote the facts and figures of the massive health care resources the Archdiocese of New York devotes to AIDS care. I could also cite Gov. Mario Cuomo's praise of Cardinal O'Connor's leadership over the past several years in delivering those medical services. (By the way, these services significantly supplement New York's contribution.)

But a better refutation of Mr.McCarthy's position may come from a personal story. This past Christmas, I spent several days in New York with my uncle and other members of my family. Our intended Christmas dinner was delayed because my uncle had gone off to St. Clare's Hospital, which is one of several Catholic hospitals in New York that cares for AIDS patients. The cardinal has been personally ministering to the sick and dying at St. Clare's for nearly a year. But this Christmas, usually a time of joy and laughter, was less so when my uncle finally arrived for dinner. St. Clare's had lost a patient during my uncle's visit. The man Mr. McCarthy suggests has less compassion than Elizabeth Taylor was as dejected and lost as I've seen him upon the deaths of close family members.

I am sure that since Mr. McCarthy is also a front-line soldier in the fight against AIDS, he is aware that medical experts report a nearly 17 percent failure rate for condoms. This estimate may be low. It happens that, in this case, Catholic doctrine that prohibits this form of artificial birth control, in favor of "just saying no," is sound medical advice. Use of a condom to prevent the spread of AIDS is a false hope of potentially tragic proportions.

Finally, though I recognize Mr.McCarthy's insinuation, I can say that my uncle is not and never has been, to my dismay, a "registered Republican." I am surprised that as avid an O'Connor watcher as Mr. McCarthy missed this widely reported but completely irrelevant fact. HUGH B. WARD JR. Arlington