The columnist Jack Anderson wrote about the thefts the next year, quoting a library official who said the institution had been “robbed blind” of papers of “incalculable value.”

The resourceful Mr. Anderson used his column to make a deal with the thief. “We have offered to act as an intermediary between the unknown scholar and the library,” he wrote. “We will guarantee not to reveal his name or otherwise identify him if he will contact us.”

It kind of worked. The thief provided photocopies of some of the documents to Mr. Anderson, who passed them along to the library. The Rehnquist letter was not among them. But a response to it solicited by Justice Frankfurter was, and it allowed the authors of the new law review article, Brad Snyder and John Q. Barrett, to reconstruct much of what Mr. Rehnquist had written.

Justice Frankfurter had made it a point to get to know the clerks in other justices’ chambers, and he and Mr. Rehnquist got along well. After Justice Jackson died in October 1954, Justice Frankfurter published tributes in two law reviews and sent copies to many of Justice Jackson’s friends and associates. Mr. Rehnquist, then in private practice, was probably on the list, and his 1955 letter was probably a response.

When Justice Frankfurter received the letter, he decided to share it with the law clerk who had succeeded Mr. Rehnquist. Over five pages, that clerk, E. Barrett Prettyman Jr., characterized and responded to Mr. Rehnquist’s letter.

Mr. Rehnquist said his former boss “had a tendency to go off half-cocked,” wrote opinions that “don’t seem to go anywhere” and did not leave “a lasting influence on the court,” Mr. Prettyman wrote in his own letter to Justice Frankfurter.

Mr. Prettyman called some of Mr. Rehnquist’s points “foolishness.” Others made him “slightly ill.”

Mr. Prettyman would go on to an exceptionally distinguished career as a Washington lawyer. He worked closely with Chief Justice John G. Roberts Jr. when the two men practiced law together at the firm now known as Hogan Lovells. (Chief Justice Roberts had also been a Supreme Court clerk — to Justice Rehnquist.)