Editing Leonard Nelson (section)

== 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" />