SHOULD PSYCHIATRISTS be held legally liable if their patients commit acts of violence that they might have predicted? Should the federal government regulate the treatment of severely handicapped infants? On the opposite page today, two medical practitioners give their views on these subjects. These are difficult questions, and thoughtful people may disagree with the writers' conclusions or feel they need to know more before making up their minds. Yet almost every day, as medical science pushes farther into uncharted legal and ethical territory, questions like these come up. How should the society try to answer them?

One way, of course, is to let litigants battle their way to a resolution in court and hope that the resulting body of law reflects a societal consensus. Or let interested parties take their causes to Congress in search of legislation. Neither one of these strikes us as a satisfactory approach. Hard cases, as they say, make bad law. And deciding how best to deal with such matters as organ transplants, gene splicing and artificial prolongation of life requires consulting more than tomes of law or even the latest medical textbook. It requires consulting general feelings about how society should conduct itself toward its weakest members and how it should best distribute its resources to promote the general welfare.

At the working level, it seems to us that the best mechanisms for deciding these issues are the ethics review committees that many hospitals have established. But these committees need and seek more general guidance. Over the last few years, such advice has been provided by the President's Commission for the Study of Ethical Problems. That body and an earlier departmental commission have for almost 10 years provided independent, nonpartisan advice on such issues as fetal experimentation, the definition of death, genetic counseling and, most recently, the patient's right to terminate treatment.

Despite the emotional nature of such issues, these commissions have operated under four presidents with a rare degree of unanimity and public acceptance. The membership has included medical practitioners, students of ethics, biomedical scientists, social scientists and just plain citizens. The president's commission has no enforcement or regulatory authority-- nor should it--but its recommendations have voluntarily been put into practice by hundreds of hospitals and served as models for several state laws.

Under the terms of its statutory charter, the commission will go out of business at the end of this month. That seems to us a shame. It is true that many commissions have developed tired blood and their purposes have devolved to simple self-perpetuation. But that's not likely to happen in an area in which the issues change daily and the interest and the stakes are so high. The society needs an independent and continuing group to keep an eye on where its medical advances are taking it.