HEARINGS on the nomination of Judge David Souter were concluded after dozens of citizens and interest groups were heard, but the most revealing and fascinating testimony was given early on by the nominee himself. Judge Souter fielded questions, described his background and his general views on constitutional issues and commented on aspects of his career in New Hampshire. Judiciary Committee chairman Joseph Biden called Judge Souter's performance a "tour de force." Other panel members were more reserved. But the consensus seems to be that the witness made his case with grace, intelligence and a reassuring discussion of his judicial philosophy.

Only a few interest groups committed specially to the preservation of abortion rights insisted that Judge Souter state his position on Roe v. Wade. That is an unappeasable demand, since that exact issue is certain to come before the Supreme Court early and often during the tenure of the justice who fills the Brennan vacancy. Senators did ask peripheral questions, though, and the nominee's responses suggested that he was more sensitive to issues involved than his advance notices indicated; it turned out that as a member of a hospital board he had voted to provide abortion services there; and he asserted that if confirmed he would come to the court without an agenda on the subject and with an open mind. Those who feared that on other matters of interest to liberals -- including civil rights, church and state, privacy and criminal justice -- his views would be reactionary, must have been reassured by his answers, some of which were so supportive of recent court decisions as to make conservatives uneasy. The same can be said of his forceful and generous tribute to Justice Brennan.

By the end of the first day of testimony, Judge Souter had gone a considerable way toward defining himself for the senators and the public, toward providing some sense of what kind of a man he is and how he sees his own role as a judge and as a potential justice. He spoke of being a listener, of being committed to preserving the Constitution for present and future generations of people "whose lives will be affected by {his} stewardship." And he emphasized what he has learned during his years on the bench in New Hampshire: that there are real people behind even the driest litigation, and they will prosper or suffer because of what he does.

Social policy is not a judge's responsibility. He cannot be expected to reach beyond his assigned powers and cure every ill. But the business of dispensing justice is more than an intellectual exercise, a matter of rules, precedent, paper and words. Judge Souter appears to understand this and promises to remember it. That sensitivity, and his no longer-questioned legal scholarship, made Judge Souter a successful witness.