Skip to main content
Go to accessibility notice


    [Albert Einstein]. Ilse Einstein Autograph Letter Signed on postcard. "Ilse Einstein." Postcard, 5.5" x 3.5", Haberlandstreet 5, Berlin; March 20, 1921. Written in German, Ilse Einstein writes to Hans Reichenbach in Stuttgart on behalf of her stepfather, Albert Einstein. An English translation of the note is presented in full:

    Most esteemed Dr. Reichenbach!
    I am returning under separate cover your manuscript. My father has reviewed the work. However, he was unable to go into any details as that was not possible because of time constraints. He is sending kind regards to you as well as to Prof. and Mrs. Regner
    With best regards,

    Ilse Einstein

    Ilse Kayser (Löwenthal-Einstein), also known as Ilse Einstein (1897-1934), was Albert Einstein's stepdaughter. She was the daughter of Elsa Einstein-Löwenthal and Rudolf Max Löwenthal. Elsa Einstein (1876-1936) was Albert Einstein's second wife; they were married from 1919, after Elsa had divorced Löwenthal, until her death in 1936.

    It is not clear from the letter to which manuscript of Reichenbach's Ilse Einstein refers. It may be a copy of a 1920 article he published in which he defended aspects of Einstein's theory of general relativity. The professor Regner to which Ilse refers is probably the physicist who Reichenbach assisted while at Technische Hochschule in Berlin. This was a busy time for Einstein; in addition to his teaching duties at the Humboldt University in Berlin and his scientific studies, he was about to make his first visit to the United States within two weeks. He would win the Nobel Prize for 1921 for his discovery of the theory of general relativity.

    Condition: Heavy toning throughout, with two file holes at top margin. A small bit of the top right corner has chipped off. Trace soiling at bottom near signature. Signature is very bold.

    More Information:

    Hans Reichenbach (1891-1953), born in Hamburg, Germany, to a half-Jewish father and a non-Jewish mother, studied civil engineering at the Technische Hochschule in Stuttgart, and then studied physics, philosophy, and mathematics in Berlin, Munich and Göttingen.He wrote his doctoral dissertation on The Concept of Probability in the Mathematical Representation of Reality, which was completed in 1915.

    After serving in the German army from 1915 to 1917, Reichenbach returned to Berlin, where he attended Albert Einstein's lectures on relativity and statistical mechanics. He was greatly influenced by Einstein and became a life-long friend of the Nobel Laureate. He wrote several popular articles defending Einstein, especially in the context of the observations of the solar eclipse of 1919 confirming the predictions of the general theory of relativity. In the early 1920s Reichenbach served on the faculty at the Technische Hochschule in Stuttgart.

    In 1920, he published The Theory of Relativity and A Priori Knowledge, which demonstrated the influence of Einstein's work. Reichenbach taught natural philosophy at the University of Berlin from 1926 to 1933, when he was forced to flee Germany under the Hitler regime. He subsequently taught in Istanbul, Turkey, and at UCLA in the U.S. Reichenbach obtained his American citizenship in 1943.

    Considered to be the greatest empiricist of the 20th Century, Reichenbach provided the backbone of empiricist philosophy. Inspired by what he perceived as a conflict between (neo-) Kantian a priorism and Einstein's relativity of space and time, Reichenbach developed a philosophy influenced by both science and an uncompromisingly empiricist epistemology.

    Auction Info

    Auction Dates
    October, 2018
    25th Thursday
    Bids + Registered Phone Bidders: 1
    Lot Tracking Activity: N/A
    Page Views: 1,226

    Buyer's Premium per Lot:
    25% on the first $250,000 (minimum $49), plus 20% of any amount between $250,000 and $2,500,000, plus 12% of any amount over $2,500,000 per lot.

    Sold on Oct 25, 2018 for: Sign-in or Join (free & quick)
    Track Item

    Heritage membership

    Join Now - It's Free

    1. Past Auction Values (prices, photos, full descriptions, etc.)
    2. Bid online
    3. Free Collector newsletter
    4. Want List with instant e-mail notifications
    5. Reduced auction commissions when you resell your
    Consign now
    • Cash Advances
    • More Bidders
    • Trusted Experts
    • Over 200,000 Satisfied Consignors Since 1976
    Consign to the 2021 October 20 Manuscripts Signature Auction.

    Learn about consigning with us

    We had a wonderful time in New York during the October 2013 Historical Manuscripts auction that featured my mother’s papers collected during her tenure as Martin Luther King, Jr.’s secretary. In fact, the entire experience from beginning to end has been a pleasure.
    Howard Ballou,
    Brandon, MS
    View More Testimonials receives more traffic than any other auction house website. (Source:

    Video tutorial

    Getting the most out of search