ONE of Justice Stevens’s trademarks is the courteousness with which he treats the lawyers who appear before the Supreme Court. When he wants to elicit information or make a point during oral argument, he typically interrupts the lawyer with the gentle preface, “May I ask you a question?”

During William Rehnquist’s tenure as chief justice, a lawyer was arguing in the court for the first time. When asked a question by Justice Anthony Kennedy, the nervous lawyer started her response with, “Well, Judge — ”

Chief Justice Rehnquist interrupted her. “That’s Justice Kennedy,” he said.

Shaken, the lawyer continued. A few minutes later, she responded to Justice David Souter by saying, “Yes, Judge.” Chief Justice Rehnquist corrected her again: “That’s Justice Souter.” A couple of minutes later, she called Chief Justice Rehnquist himself a judge.

The chief justice leaned forward, his deep voice now at its sternest, to say, “Counsel is admonished that this court is composed of justices, not judges.”

Before the lawyer could say anything, Justice Stevens interjected: “It’s O.K., Counsel. The Constitution makes the same mistake.”