Pioneering and highly influential founder of psychoanalysis (1856–1939) whose theories revolutionized the understanding the human psyche. ALS in German, signed “Freud,” one page, 5.75 x 9, personal letterhead, September 15, 1929. Freud writes to a colleague, Dr. Feigenbaum. In full: “Here is the introduction, as promised. I am not sure, however, if I am indeed doing you a favor with same—It is very coarse and candid. Perhaps, in your opinion an utterance like that may not be deemed acceptable for use in your new publication in the U.S. Should you decide against making use of it, I shall certainly not be offended. If you do take the plunge, I urge you to carefully evaluate the wording, as much depends on the nuance. I am curious to learn what your decision will be.” Feigenbaum was one of Sigmund Freud's first students, and was a psychiatrist who was then running an institution for the mentally ill in Jerusalem. Suede matted with a seated portrait of Freud, to an overall size of 19.5 x 15. A bit of scattered light wrinkling, otherwise condition is very fine. Auction LOA John Reznikoff/PSA/DNA and R&R COA.