Guide to the Papers of Ernst Marcus (1856-1928)

AR 4322 / MF 1019

Processed by Katharina Hoffmann

Leo Baeck Institute

Center for Jewish History

15 West 16th Street

New York, N.Y. 10011

Phone: (212) 744-6400

Fax: (212) 988-1305



© 2009 Leo Baeck Institute. All rights reserved.
Center for Jewish History, Publisher.
Electronic finding aid was encoded in EAD 2002 by Dianne Ritchey in August 2009. Description is in English.
September 2010: Links to digital objects added in Container List. 2010-09-20  encoding of linking to digital objects from finding aid was changed from <extref> to <dao> through dao_conv.xsl

Descriptive Summary

Creator: Marcus, Ernst, 1856-1928
Title: Ernst Marcus Collection
Dates:bulk 1900-1928
Abstract: This collection contains manuscripts by Ernst Marcus, as well as notes and diaries in which he recorded his philosophical ideas. There is also correspondence of a philosophical nature with Rebecca Hanf and Salomo Friedlaender, and original clippings of newspaper articles written by Ernst Marcus.
Languages: The collection is in German.
Quantity: 0.5 linear foot.
Identification: AR 4322 / MF 1019
Repository: Leo Baeck Institute
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Biographical Note

Ernst Marcus was born September 3, 1856, in Kamen in Westphalia. He studied law in Bonn and Berlin. In 1889 he started becoming engaged in philosophical questions. At this time he worked professionally as an assessor. In 1890 he became a judge in Essen. He married Berta Auerbach in 1893, and they had three children. In 1899 he started meeting with the philosopher Salomo Friedlaender. Very early, Friedlaender became aware of Ernst Marcus's potential and the relevance of his ideas. He supported him and admired his theses. When Friedlaender published under the pseudonym Mynona he even used Marcus as a figure called "Sucram". In 1904 Ernst Marcus met Rebecca Hanf, who was interested in philosophy as well. They became friends and corresponded until Marcus’s death. Due to the discussions they had, Rebecca Hanf regarded their relationship later as a friendship between a willing teacher and an open-minded student. Ernst Marcus wrote many books that are also preserved in the LBI library.

Philosophically, Ernst Marcus dealt with Immanuel Kant's and Albert Einstein's theories. Ernst Marcus regarded himself as the "one who resurrected Kant from death and who understood Kant utterly." He emphasized that all his knowledge about philosophy and its analysis he taught himself and in a university. Ernst Marcus died in Essen on October 29, 1928.

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Scope and Content Note

This collection contains Ernst Marcus's correspondence, notes and articles by him and about him.

Series I preserves his correspondence with Salomo Friedlaender and Rebecca Hanf. This correspondence discusses philosophical ideas in general and the interpretation of Kant's theories as well as Einstein's theory of relativity. This series also includes two of Marcus' manuscripts typed by Salomo Friedlaender. It also contains single letters to philosophy professors Hans Vaihinger, Hugo Dingler and Walter Riese.

Series II contains Ernst Marcus's notes and (concepts, his diary, as well as articles and notes about him. Topics include interpretations of theories by Kant, Schopenhauer, Nietzsche and other philosophers, and other topics like morality, religion, etc. This series also contains original clippings of newspaper articles by Ernst Marcus and some pictures of him.

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The collection is arranged in two series as the following manner:

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Access and Use

Access Restrictions

Open to researchers.

Collection is digitized.

Collection is microfilmed; use MF 1019.

Access Information

Readers may access the collection by visiting the Lillian Goldman Reading Room at the Center for Jewish History. We recommend reserving the collection in advance; please visit the LBI Online Catalog and click on the "Request" button.

Use Restrictions

There may be some restrictions on the use of the collection. For more information, contact:
Leo Baeck Institute, Center for Jewish History, 15 West 16th Street, New York, NY 10011

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Access Points

Click on a subject to search that term in the Center's catalog. Return to the Top of Page

Related Material

The LBI library provides the following books by Ernst Marcus:

Books about Ernst Marcus by Salomo Friedlaender, Robert Marcus and others are also available in the LBI Library.

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Custodial History

[information about the chain of ownership of the materials being described, before reaching the archive]

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Collection is available on 1 reel of microfilm (MF 1019).

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Preferred Citation

Published citations should take the following form:

Identification of item, date (if known); Ernst Marcus Collection; AR 4322; box number; folder number; Leo Baeck Institute.

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Processing Information

The collection was organized in folders, and lists of contents were made. Apparently, some material was added later and it made sense to separate the folders into series. The original folder of material donated, however (Folder 1), was kept in its original order.

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Other Finding Aid

An older paper item-level inventory is available for part of the collection.

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Container List


Series I: Correspondence, 1899-1928

This series is in German.
0.125 foot


Scope and Content:

This series is comprised of letters by Ernst Marcus to his long-term correspondent Rebecca Hanf, and, in a lesser amount, to Salomo Friedlaender. Rebecca Hanf got to know Ernst Marcus in 1904 and due to her interest in his work and philosophy in general they started a correspondence. The Einstein theory of relativity engaged Ernst Marcus in particular during the years he wrote letters to Rebecca Hanf. Like other philosophers of his time, Ernst Marcus criticized Einstein's theory and tried to disprove it. Folder 1 contains letters by Ernst Marcus to professors of philosophy concerning his interpretation of Kant's and other philosophers' theories. He discusses other philosophical theories and ideas, including analyzing Kant. In one chapter in his note/ blueprint script he refers to one of the letters he wrote to Rebecca Hanf. That particular letter concerned the discussion about a "sacrificing God", i.e. the crucifixion of Jesus Christ. Years after his death Salomo Friedlaender typed the manuscripts to preserve Marcus's intellectual inheritance.

11Letters and Manuscripts1899-1928
12Letters to Rebecca Hanf1904-1928
12Letters to Rebecca Hanf - Theory of Relativity1904-1927
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Series II: Writings and Articles, 1902-1976

This series is in German.
0.25 linear foot.


Scope and Content:

This series contains notes and concepts by Ernst Marcus, and his diaries. Ernst Marcus himself classified his diary as a blueprint of his unproven ideas, and that therefore he made a note explaining that the following thoughts seemed to be new to him but did not have to be. He titled every entry. Robert Marcus typed his diary and made an exact list of its contents. The typescript with his notes and ideas can be regarded as his revised diary. In these typescripts he discusses not only theses by Albert Einstein and Immanuel Kant but also Schopenhauer, who inspired him to do further studies on Kant, Nietzsche and Darwin. Ernst Marcus was also engaged in the philosophical aspects of physics and psychology. One of Ernst Marcus’s main topics was ethics, discussing religion/Christianity, rationality, and belief. His diary contains documented conversations with the philosophers Hermann Cohen and Dr. Carl Vorlaender.

This series also includes a typescript by Salomo Friedlaender titled “Kants Thronerbe” which was published after Marcus’ death.

Folder 4 contains several articles about Ernst Marcus by Rebecca Hanf, Salomo Friedlaender, Karl Rosenberg and others. It includes as well a note by Rebecca Hanf about the first time she met Ernst Marcus and how they became philosophical correspondents, and a similar note by Robert Marcus. There are also pictures of Ernst Marcus: photos of him in his office, photos of his death mask and etchings of him. The folder also contains original newspaper articles by Ernst Marcus and by others about Ernst Marcus’s work.

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