"I have read your letter and enclosures on the Russell-Tarski affair with interest, and have read again the recommendations of Tarski that I sent to City College, Columbia, Cornell, Princeton, California, and Guggenheim in 1939-41. I made no use of Russell's statement in any of them. I think I can see why: mathematical logic was a fast growing subject, and Russell had long since turned elsewhere. I seem to remember someone saying that Russell's statement had been transmitted by Ernest Nagel. This may have been a conjecture."