Editing Leonard Nelson

{{Short description|German philosopher and mathematician (1882–1927)}}
{{Distinguish|Lennart Nilsson}}
{{Infobox philosopher
| name              = Leonard Nelson
| image             = Leonard Nelson (1882-1927) digitalised.jpg
| alt               = 
| caption           = Nelson in 1922
| birth_date        = 11 July 1882
| birth_place       = [[Berlin]], [[Brandenburg]], [[Prussia]], [[German Empire]]
| death_date        = 29 October 1927 (aged 45)
| death_place       = [[Göttingen]], [[Weimar Republic|Germany]]
| spouse            = {{marriage|Elisabeth Schemmann<ref>{{Cite web|url=https://www.deutsche-biographie.de/sfz71062.html|title=Nelson, Leonard - Deutsche Biographie|last=Biographie|first=Deutsche|website=www.deutsche-biographie.de|language=de|access-date=2019-08-29}}</ref>|1907|1912|end=divorced}}
| partner           = [[Minna Specht]] (since 1915)
| education         = [[Französisches Gymnasium Berlin]]<br>[[Heidelberg University]]<br>[[Humboldt University of Berlin]]<br>[[University of Göttingen]] (PhD, 1904; Dr. phil. hab., 1909)
| notable_works     =
| awards            = 
| era               = [[20th-century philosophy]]
| region            = [[Western philosophy]]
| school_tradition  = [[Neo-Friesian school|Neo-Friesian]] 
| institutions      = [[University of Göttingen]]
| thesis_title      = Jakob Friedrich Fries und seine jüngsten Kritiker 
| thesis_url        = https://gallica.bnf.fr/ark:/12148/bpt6k955023/f88.image.texteImage 
| thesis_year       = 1904 
| doctoral_advisor  = [[Julius Baumann]] 
| academic_advisors = 
| doctoral_students = 
| notable_students  = [[Paul Bernays]], [[Gustav Heckmann]], [[Gerhard Weisser]], [[Fritz Eberhard]], [[Alfred Kubel]], [[Willi Eichler]]
| main_interests    = [[Critical philosophy]], [[philosophy of science]], [[logic]]
| notable_ideas     = [[Grelling–Nelson paradox]], revival of the [[Socratic method]]
}}

'''Leonard Nelson''' ({{IPAc-en|ˈ|n|ɛ|l|s|ə|n}}; {{IPA|de|ˈnɛlzɔn|lang}}; 11 July 1882 – 29 October 1927), sometimes spelt '''Leonhard''', was a German [[mathematician]], [[Critical philosophy|critical philosopher]], and [[socialist]]. He was part of the [[neo-Friesian school]] (named after [[post-Kantian]] philosopher [[Jakob Friedrich Fries]]) of [[neo-Kantianism]] and a friend of the mathematician [[David Hilbert]]. He devised the [[Grelling–Nelson paradox]] in 1908 and the related idea of [[autological word]]s with [[Kurt Grelling]].<ref>{{cite book |first1=K. |last1=Grelling |first2=L. |last2=Nelson |chapter=Bemerkungen zu den Paradoxien von Russell und Burali-Forti |title=Abhandlungen der Fries'schen Schule II |location=Göttingen |year=1908 |pages=301–334 }} Also in: {{cite book |first=Leonard |last=Nelson |title=Gesammelte Schriften III. Die kritische Methode in ihrer Bedeutung für die Wissenschaften |publisher=Felix Meiner Verlag |location=Hamburg |year=1974 |pages=95–127 |isbn=3787302220 }}</ref>

Nelson subsequently became influential in both philosophy and mathematics, as his close contacts with scientists and mathematicians influenced their ideas. Despite dying earlier than many of his friends and assistants, his [[Internationaler Sozialistischer Kampfbund|ISK]] organization lived on after his death, even after being banned by the [[Nazi Regime]] in 1933. It is even claimed that [[Albert Einstein]] supported it.<ref>{{Cite web|url=http://www.sgipt.org/gesch/kronf/kronf_e.htm|title=Fate and work of a Jewish psychiatrist and psychotherapist|website=www.sgipt.org|access-date=2019-08-30}}</ref> He's also credited with popularizing the [[Socratic method]] in his book ''Die sokratische Methode'' (''The Socratic Method'').<ref>{{Cite book|url=http://www.allerart.de/walkemuehle/sokratische_methode/Die_sokratische_Methode-Leonard_Nelson_1922.pdf|title=Die sokratische Methode|last=Nelson|first=Leonard|year=1931|location=Göttingen}}</ref>

== Life ==
=== Early life and education ===
Leonard Nelson was the son of [[lawyer]] Heinrich Nelson (1854–1929) and [[Painting|artist]] Elisabeth Lejeune Dirichlet (1860–1920).<ref>{{Cite web|url=https://www.geni.com/people/Leonard-Nelson-Prof-Dr/6000000002802349438|title=Leonard Nelson, Prof. Dr.|website=geni_family_tree|date=11 July 1882 |language=en-US|access-date=2019-08-30}}</ref> His mother was the granddaughter of mathematician [[Peter Gustav Lejeune Dirichlet]] and descendant of [[Jewish]] philosopher [[Moses Mendelssohn]].<ref name="Mendelssohn">{{Cite web|url=https://www.epischel.de/ahnenforschung/wt/individual.php?pid=I442&ged=mendelssohn|title=Leonard Nelson 1882–1927 – Stammbaum Moses Mendelssohn|website=www.epischel.de|access-date=2019-08-30}}</ref> Nelson was baptised as a [[Protestantism|Protestant]] at the age of five on 13 June 1887.<ref>{{Cite book|title=Franke, S. 53.}}</ref>

Nelson studied at [[Französisches Gymnasium Berlin]], where mathematics and science were not a focus of the curriculum. He was therefore privately tutored by mathematician [[Gerhard Hessenberg]] (1874–1925), and began reading the works of philosophers [[Immanuel Kant]], [[Jakob Friedrich Fries]], and [[Ernst Friedrich Apelt]]s, which began to spark his interest in philosophy.

In 1901, Nelson studied mathematics and philosophy at [[Heidelberg University]] for a short period of time before going to [[Humboldt University of Berlin|Friedrich Wilhelm University]] (today: Humboldt-Universität) in Berlin, from March 1901 to 1903. From 1903 to 1904, he worked with mathematicians and philosophers at the [[University of Göttingen]], such as his [[doctoral advisor]] [[Julius Baumann]], [[David Hilbert]], [[Felix Klein]], [[Carl David Tolmé Runge|Carl Runge]], and his later rival [[Edmund Husserl]].

Nelson's work as a philosopher was most concerned with [[critical philosophy]], attributed to Kant. It sets out to find a "critique" on science and [[metaphysics]], similar to [[empiricism]],<ref>{{Cite web|url=https://www.marxists.org/reference/archive/hegel/works/sl/sl_iv.htm|title=IV SECOND ATTITUDE OF THOUGHT TO OBJECTIVITY|website=www.marxists.org|access-date=2019-09-01}}</ref> as things can only be true based on the perceptions and limitations on human minds. Kant's 1781 book ''[[Critique of Pure Reason]] (Kritik der reinen Vernunft)'' inspired Nelson to go down the path of critical philosophy, and later followed the works of [[post-Kantian]] philosopher [[Jakob Friedrich Fries|Fries]] who had also followed Kant's work.<ref name=":3" />

His first dissertation was ''Die kritische Methode und das Verhältnis der Psychologie zur Philosophie'' (''The Critical Method and the Relationship of Psychology to Philosophy''), which failed. His 1904 dissertation ''[[Jakob Friedrich Fries|Jakob Fries]] and his Latest Critics'' (''Jakob Friedrich Fries und seine jüngsten Kritiker'') was successful. Nelson continued defending Fries' philosophy and ideas by publishing a ''neue Folge'' (new series) of ''Abhandlungen der Fries'schen Schule'' (1904) with Gerhard Hessenberg and mathematician Karl Kaiser. It was here that Nelson and these same friends created the ''Jakob-Friedrich-Fries-Gesellschaft'' (Jakob Friedrich Fries Society) to promote critical philosophy.<ref name=":3" />

=== Career ===
Ready to form new ideas, Nelson founded the [[Neo-Friesian School]] in 1903, with some well-known members, such as [[Rudolf Otto]], philosopher (1869–1937), [[Gerhard Hessenberg]], mathematician (1874–1925) and [[Otto Fritz Meyerhof|Otto Meyerhof]]. [[biochemist]] (1884–1951). Other notable people, such as philosopher [[Kurt Grelling]] and mathematician [[Richard Courant]] (student of Hilbert), joined after its foundation. A larger list of ISK members and similar can be seen in the [[list of Germans who resisted Nazism]].

In 1909 he habilitated at the [[University of Göttingen]] and became ''[[Privatdozent]]''. From June 1919 until his death on 29 October 1927 he was a professor in Göttingen.<ref name=":3">{{Cite web|url=https://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/nelson-leonard-1882-1927|title=Nelson, Leonard (1882–1927) {{!}} Encyclopedia.com|website=www.encyclopedia.com|access-date=2019-08-30}}</ref><ref name=":1">{{Cite web|url=https://www.deutsche-biographie.de/sfz71062.html#ndbcontent|title=Nelson, Leonard - Deutsche Biographie|last=Biographie|first=Deutsche|website=www.deutsche-biographie.de|language=de|access-date=2019-08-30}}</ref><ref name=":2">{{Cite web|url=https://www.tier-im-fokus.ch/mensch_und_tier/leonard_nelson|title=tier-im-fokus.ch » Leonard Nelson, vergessener Tierrechtler|website=www.tier-im-fokus.ch|date=7 September 2010 |access-date=2019-08-30}}</ref>

In 1922, Nelson founded the ''Philosophisch-Politische Akademie'' (Philosophical-Political Academy or PPA) as a "[[Platonic Academy]]" and non-profit association, which was abandoned soon after the Nazis banned it, but re-established in 1949. It still stands today for political discussions between philosophers and politicians,<ref>{{Cite web|url=http://www.philosophisch-politische-akademie.de/index.html#top|title=Philosophisch-Politische Akademie (PPA)|website=www.philosophisch-politische-akademie.de|access-date=2019-09-01|archive-date=2019-10-07|archive-url=https://web.archive.org/web/20191007222209/http://www.philosophisch-politische-akademie.de/index.html#top|url-status=dead}}</ref> and was supported financially by the ''Gesellschaft der Freunde der Philosophisch-Politischen Akademie'' (Society of Friends of the Philosophical-Political Academy or GFA).<ref>{{Cite book|url=https://books.google.com/books?id=DNckDwAAQBAJ&q=%22Gesellschaft+der+Freunde+der+Philosophisch-Politischen+Akademie%22&pg=PA6|title=Exile and Gender II: Politics, Education and the Arts|date=2017-05-30|publisher=BRILL|isbn=9789004343528|language=en}}</ref> They started working with an education center called ''[[Landerziehungsheim]] Walkemühle'', founded in 1921 by a support of Nelson, [[Progressive education|progressive teacher]] Ludwig Wunder (1878–1949). Although Wunder left it shortly after in 1924, educator and co-worker of Nelson, [[Minna Specht]], took over,<ref>{{Cite web|url=http://www.philosophisch-politische-akademie.de/lene.html#top|title=Philosophisch-Politische Akademie (PPA)|website=www.philosophisch-politische-akademie.de|access-date=2019-09-01|archive-date=2019-10-07|archive-url=https://web.archive.org/web/20191007222205/http://www.philosophisch-politische-akademie.de/lene.html#top|url-status=dead}}</ref> with the help of journalist and author [[Mary Saran]].

==== Internationaler Sozialistischer Kampfbund (ISK) ====
In 1917 Nelson and [[Minna Specht]] founded the ''Internationaler Jugendbund'' (International Youth Federation or IJB). In 1918, Nelson briefly became a  member of the [[Independent Social Democratic Party of Germany|Independent Social Democratic Party]] (USPD), and from 1923–1925 he was a member of the [[Social Democratic Party of Germany|Social Democratic Party]] (SPD), until he was ultimately excluded. As a result, in 1925, he and Minna Specht founded the [[Internationaler Sozialistischer Kampfbund]] ''(''ISK; "International Socialist Militant League")  merging it with the IJB by taking over its publishing label, ''Öffentliches Leben''.<ref name=":1" /> Among Leonard Nelson's students and political companions in the International Socialist Kampfbund were also<ref>{{Cite book|title=The Socratic Conversation in theory and practice|last=Horster|first=Detlef|publisher=Leske + Budrich|year=1994|location=Opladen|page=30}}</ref> [[Minister-President of Lower Saxony|Prime Minister]]  [[Alfred Kubel]] (1909–1999) and journalist [[Fritz Eberhard]] (1896–1982), later member of the [[Parlamentarischer Rat]].
=== Personal life ===
{{see also|Mendelssohn family}}
Nelson married Elisabeth Schemmann (1884–1954), in 1907, but divorced in 1912 after she baptised their son Gerhard David Wilhelm Nelson (1909–1944) in the [[Lutheranism|Lutheran Church]]. Nelson's refusal to baptise his son and divorce was a big change based on his Jewish ancestry. He even resigned from the [[Evangelicalism|Evangelical Church]] in 1919.<ref>{{Cite book|title=Franke S. 153, F. 868.}}</ref>

His wife married [[Paul Hensel]] in 1917.<ref>{{Cite book|title=Leonard Nelson|last=Franke|first=Holger |publisher=Verlag an der Lottbek|year=1991|location=Ammersbek near Hamburg|page=93}}</ref>

Nelson was an early advocate of [[animal rights]] and a [[Vegetarianism|vegetarian]].<ref>Milkov, Nikolay; Peckhaus, Volker. (2013). ''The Berlin Group and the Philosophy of Logical Empiricism''. pp. 13-14. {{ISBN|9789400754850}}</ref> His lecture "Duties to Animals" was published posthumously in Germany in 1932 and included in his book ''A System of Ethics'' (translated in 1956) and reprinted in the 1972 book ''[[Animals, Men and Morals]]''.<ref>{{cite journal|author=Lengauer, Erwin|year=2020|title=Tom Regan's Philosophy of Animal Rights: Subjects-of-a-Life in the Context of Discussions of Intrinsic and Inherent Worth|journal=Problemos|url=https://www.researchgate.net/publication/340972300|volume=97|issue=|pages=87–98|doi=10.15388/Problemos.97.7 |s2cid=219087415 |doi-access=free}}</ref>
Nelson was an [[insomnia]]c and died at a young age from [[pneumonia]], and was buried at a Jewish cemetery in [[Melsungen]] alongside his father Heinrich.<ref name=":5" />

==Posthumous legacy==
In the summer of 1997 his granddaughter, Maria Nelson, and Maria's daughter, Rachel Urban, both visited his grave .<ref name=":5">{{Cite web|url=https://www.landerziehungsheim-walkemuehle.de/index.php?title=Ereignisse|title=Ereignisse – wiki.landerziehungsheim-walkemuehle.de|website=www.landerziehungsheim-walkemuehle.de|access-date=2019-09-01}}</ref>

Nelson's ideas continued to have an impact upon German socialism and communism in [[Nazi Germany]] as the ISK's members became active in the left-wing resistance to Nazism.{{citation needed|date=May 2023}}

== Bibliography ==
Nelson published numerous books and papers, often with the help of other philosophers and mathematicians. He was later critical of [[Georg Wilhelm Friedrich Hegel]] in his work ''Progress and Regress in Philosophy'' (''Fortschritte und Rückschritte der Philosophie''). He is also known for defending the idea of animal rights in his work ''System of Philosophical Ethics and Pedagogy'' (''System der philosophischen Ethik und Pädagogik'') published in 1932, with the help of his assistant [[Grete Hermann]] (also part of the ISK) and Minna Specht.<ref>Nelson, Leonard, ''System of Ethics'', Yale University Press, New Haven, 1956, p. 142.</ref>

Some of his works are already mentioned above, but some others, available in the [[Internet Archive]] (and other websites, if not available there), include:

=== Published works ===
*1908 – ''Ist metaphysikfreie Naturwissenschaft möglich?'' Sonderdruck aus den ''Abhandlungen der Fries’schen Schule'', II. Bd., 3. Heft. Vandenhoeck & Ruprecht, Göttingen 1908 [[iarchive:istmetaphysikfr00nelsgoog|Internet Archive]]
*1908 – ''Über das sogenannte Erkenntnisproblem''. Vandenhoeck & Ruprecht, Göttingen 1908 [http://www.archive.org/details/uberdassogenann00nelsgoog Internet Archive]
*1908 – ''Über wissenschaftliche und ästhetische Naturbetrachtung''. Vandenhoeck & Ruprecht, Göttingen 1908 [[iarchive:berwissenschaft00nelsgoog|Internet Archive]]
* ''Ethische Methodenlehre.'' by Veit & Comp., Leipzig 1915[[iarchive:ethischemethoden00nels|Internet Archive]]
*1917 – ''Die Rechtswissenschaft ohne Recht: kritische Betrachtungen über die Grundlagen des Staats- und Völkerrechts insbesondere über die Lehre von der Souveränität''. Veit & Comp, Leipzig 1917 [http://www.archive.org/details/dierechtswissens00nels Internet Archive]
*1917 – ''Vorlesungen über die Grundlagen der Ethik''. Veit & Comp., Leipzig
** Bd. 1: ''Kritik der praktischen Vernunft''. 1917 [[iarchive:kritikderpraktis00nels|Internet Archive]]
* ''Die sokratische Methode.'' Vortrag, gehalten am 11. Dezember 1922 in der Pädagogischen Gesellschaft in Göttingen. In: ''Abhandlungen der Fries’schen Schule. Neue Folge.''Hrsg. v. Otto Meyerhof, Franz Oppenheimer, Minna Specht. 5. Band, H. 1. Öffentliches Leben, Göttingen 1929, S. 21–78.
*1919 – ''Demokratie und Führerschaft'', Public life, Berlin 1932. [https://www.digitale-sammlungen.de/de/view/bsb11128374?page=1 Internet Archive]
*1920 – ''System der philosophischen Rechtslehre''. Verlag der Neue Geist / Reinhold, Leipzig 1920 [http://www.archive.org/details/systemderphiloso00nels Internet Archive]
*1922 – ''Die Reformation der Gesinnung: durch Erziehung zum Selbstvertrauen''. The New Publishes, Leipzig 1922 [[iarchive:diereformationde00nels|Internet Archive]]
*1922 – ''Die sokratische Methode'', Lecture, held on December 11, 1922 in the Pedagogical Society in Göttingen. In: ''Treatises of the Friesian school. New episode.'' edited by [[Otto Fritz Meyerhof|Otto Meyerhof]], [[Franz Oppenheimer]], [[Minna Specht]]. 5th volume, Göttingen 1929, pp.&nbsp;21–78. [[iarchive:DieSokratischeMethodeLeonardNelson|Internet Archive]]
* ''Ausgewählte Schriften. Studienausgabe.'' Hrsg. und eingeleitet von Heinz-Joachim Heydorn. Europäische Verlagsanstalt, Frankfurt 1974.
* ''Vom Selbstvertrauen der Vernunft: Schriften zur krit. Philosophie und ihrer Ethik.'' Hrsg. von Grete Henry-Hermann (''Philosophische Bibliothek''. Band 288). Meiner, Hamburg 1975.
*2011 – {{Cite book |title=Typische Denkfehler in der Philosophie |date=April 2011 |publisher=Felix Meiner Verlag |isbn=978-3787321490}}, a series of lectures, delivered from April to July 1921 that was omitted from his collected works. English translation {{Cite book |title=A Theory of Philosophical Fallacies |translator-last1=Leal |translator-first1=Fernando |translator-last2=Carus |translator-first2=David |year=2016 |publisher=Springer |isbn= 978-3-319-20782-7}}

=== ''Gesammelte Schriften in neun Bänden'' ===
English translation: "Collected Writings in Nine Volumes". It was published by [[Paul Bernays]] and ''Felix Meiner Verlag'' (a German scientific [[Publishing|publishing house]] in philosophy), in [[Hamburg]] 1970-1977;<ref>{{Cite web|url=https://www.booklooker.de/B%C3%BCcher/Angebote/autor=Leonard+Nelson&titel=Gesammelte+Schriften+in+neun+B%C3%A4nden|title="Leonard Nelson, Gesammelte Schriften in neun Bänden" – Bücher gebraucht, antiquarisch & neu kaufen|website=www.booklooker.de|language=de|access-date=2019-09-01}}</ref>

* Volume I: ''Die Schule der kritischen Philosophie und ihre Methode''
* Volume II: ''Geschichte und Kritik der Erkenntnistheorie''
* Volume III: ''Die kritische Methode in ihrer Bedeutung für die Wissenschaft''
* Volume IV: ''Kritik der praktischen Vernunft''
* Volume V: ''System der philosophischen Ethik und Pädagogik''
* Volume VI: ''System der philosophischen Rechtslehre und Politik''
* Volume VII: ''Fortschritte und Rückschritte der Philosophie von Hume und Kant bis Hegel und Fries''
* Volume VIII: ''Sittlichkeit und Bildung''
* Volume IX: ''Recht und Staat''

==References==
{{Reflist}}

==External links==
* [https://web.archive.org/web/20010411032918/http://www.sfcp.org.uk/nelson.htm Biography from the SFCP site]
* ''[https://web.archive.org/web/20180205123431/https://my.fit.edu/~aberdein/Nelson.pdf A Theory of Philosophical Fallacies]'' by Andrew Aberdein (in-depth review)
* [http://www.worldcat.org/identities/lccn-n84-801385/ worldcat.org], Nelson, Leonard (1882-1927)
* ''[http://library.fes.de/inhalt/digital/funke/pdf/1932/19320712.pdf Der Funke]'' newspaper, 12 July 1932 – Leonard Nelson's 50th anniversary (in German)
* [https://wiki.landerziehungsheim-walkemuehle.de/dokumente/HNA_MG_2017-11-28_003.pdf Newspaper] by Judith Féaux de Lacroix, [[Melsungen|Melsunger]] edition of the ''[[Hessische/Niedersächsische Allgemeine|Hessisch-Niedersächsische Allgemeine]]'' (28 November 2017) (in German)
* [http://www.allerart.de/walkemuehle/index.shtml "Minna Specht, Leonard Nelson, IJB und ISK"]. ''www.allerart.de'' (in German)
* {{MathGenealogy|id=51875}}

{{Animal rights|state=uncollapsed|advocates}}
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{{DEFAULTSORT:Nelson, Leonard}}
[[Category:1882 births]]
[[Category:1927 deaths]]
[[Category:19th-century German Jews]]
[[Category:20th-century German mathematicians]]
[[Category:German animal rights scholars]]
[[Category:German socialists]]
[[Category:Jewish philosophers]]
[[Category:Jewish socialists]]
[[Category:Kantian philosophers]]
[[Category:University of Göttingen alumni]]
[[Category:Writers from Berlin]]
[[Category:Deaths from pneumonia in Germany]]
[[Category:Französisches Gymnasium Berlin alumni]]
[[Category:20th-century German philosophers]]
[[Category:Humboldt University of Berlin alumni]]