# About the LOR of John Nash, was there any relationship between Richard Duffin and Solomon Lefschetz?

In Academia SE, there is a question about the credibility of Prof. Richard Duffin, who wrote the notorious letter of recommendation for John Nash, who later received the Nobel Memorial Prize in Economic Sciences. Its answers focus on the credibility of Duffin to the academic/mathematic world. However, since this letter was sent directly to Prof. Solomon Lefschetz, not the adcom, so I have another theory that Duffin had directly credibility to Lefchetz, that is they were friends, or at least know each other personally.

Do you know the relationship between these two professors? I have check their Wikipedia page, but I can't find any evidence.

Will a recommendation letter such as that written for John F. Nash be convincing? on Academia
John Forbes Nash, Jr, Richard Duffin, Solomon Lefchetz on Wikipedia
Image taken from the Graduate Alumni Records of Princeton University:

• I suggest a couple of tags: credibility. famousness, LOR, friendship Sep 17 '15 at 10:42
• If you would like to propose these tags, you should probably take it to History of Science and Mathematics Meta. However, I don't think they're good tags because they're (1) too specific (2) not directly related to the history of science and mathematics.
– Danu
Sep 20 '15 at 18:27
• Duffin was a very serious, well-respected scholar, and would not have risked his reputation on frivolities, I think. Thus, the starkness of the letter would surely have signalled a singular case to Lefschetz. Jul 17 '18 at 22:56
• Duffin was also the PhD advisor of Raoul Bott, with whom he wrote a famous paper about electrical circuit theory. Duffin did serious mathematics; for example, modern "frame theory" starts with a paper of Duffin and Schaefer. Jul 19 '18 at 7:25