Leonard Nelson (; ; 11 July 1882 – 29 October 1927), sometimes spelt Leonhard, was a German

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

, critical philosopher, and

socialist Socialism is a left-wing economic philosophy and movement encompassing a range of economic systems characterized by the dominance of social ownership of the means of production as opposed to private ownership. As a term, it describes the ...

. He was part of the

neo-Friesian school In late modern continental philosophy, neo-Kantianism (german: Neukantianismus) was a revival of the 18th-century philosophy of Immanuel Kant. The Neo-Kantians sought to develop and clarify Kant's theories, particularly his concept of the "thing ...

(named after post-Kantian philosopher

Jakob Friedrich Fries Jakob Friedrich Fries (; 23 August 1773 – 10 August 1843) was a German post-Kantian Terry Pinkard, ''German Philosophy 1760-1860: The Legacy of Idealism'', Cambridge University Press, 2002, pp. 199–212. philosopher and mathematician. Biog ...

) 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 An autological word (also called homological word) is a word that expresses a property that it also possesses (e.g., "word" is a word, "noun" is a noun, "English" is an English word, " pentasyllabic" has five syllables, and "writable" is writab ...

s with

Kurt Grelling Kurt Grelling (2 March 1886 – September 1942) was a German logician and philosopher, member of the Berlin Circle. Life and work Kurt Grelling was born on 2 March 1886 in Berlin. His father, the Doctor of Jurisprudence Richard Grellin ...

. Neo-Friesian subsequently became an influencer in fields of both philosophy and mathematics, as Nelson's close contacts with scientists and mathematicians influenced their ideas. Despite dying earlier than many of his friends and assistants, his ISK organization lived on after his death, even after being banned by the

Nazi Regime Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

in 1933. It is even claimed that

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...

supported it. He's also credited with popularizing the

Socratic method The Socratic method (also known as method of Elenchus, elenctic method, or Socratic debate) is a form of cooperative argumentative dialogue between individuals, based on asking and answering questions to stimulate critical thinking and to draw ...

in his book ''Die sokratische Methode'' (''The Socratic Method'').

Life

Early life and education

In Nelson's early years, he studied in

Französisches Gymnasium Berlin The Französisches Gymnasium (french: Lycée français de Berlin) is a long-existing francophone gymnasium in Berlin, Germany. Traditionally, it is widely regarded as an elite high school. It is also the oldest public school in Berlin. Its creat ...

where mathematics and science weren't notable in that school. He was therefore privately tutored by mathematician Gerhard Hessenberg (1874–1925), and began reading the works of philosophers

Immanuel Kant Immanuel Kant (, , ; 22 April 1724 – 12 February 1804) was a German philosopher and one of the central Enlightenment thinkers. Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and aes ...

, and Ernst Friedrich Apelts, which began to spark his interest in philosophy. In 1901, Nelson studied mathematics and philosophy in

Heidelberg University } Heidelberg University, officially the Ruprecht Karl University of Heidelberg, (german: Ruprecht-Karls-Universität Heidelberg; la, Universitas Ruperto Carola Heidelbergensis) is a public research university in Heidelberg, Baden-Württemberg, ...

for a short period of time, before going to the

Humboldt University of Berlin The Humboldt University of Berlin (german: link=no, Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a public university, public research university in the central borough of Mitte in Berlin, Germany. The university was established ...

from March 1901 – 1903. From 1903 to 1904, he worked with mathematicians and philosophers in the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded i ...

, such as; his doctoral advisor

Julius Baumann The gens Julia (''gēns Iūlia'', ) was one of the most prominent patrician families in ancient Rome. Members of the gens attained the highest dignities of the state in the earliest times of the Republic. The first of the family to obtain the c ...

, David Hilbert,

Felix Klein Christian Felix Klein (; 25 April 1849 – 22 June 1925) was a German mathematician and mathematics educator, known for his work with group theory, complex analysis, non-Euclidean geometry, and on the associations between geometry and grou ...

Carl Runge Carl David Tolmé Runge (; 30 August 1856 – 3 January 1927) was a German mathematician, physicist, and spectroscopist. He was co-developer and co-eponym of the Runge–Kutta method (German pronunciation: ), in the field of what is today known ...

, and his later rival

Edmund Husserl , thesis1_title = Beiträge zur Variationsrechnung (Contributions to the Calculus of Variations) , thesis1_url = https://fedora.phaidra.univie.ac.at/fedora/get/o:58535/bdef:Book/view , thesis1_year = 1883 , thesis2_title ...

Critical philosophy

Nelson's work as a philosopher was most concerned with

critical philosophy The critical philosophy (german: kritische Philosophie) movement, attributed to Immanuel Kant (1724–1804), sees the primary task of philosophy as criticism rather than justification of knowledge. Criticism, for Kant, meant judging as to the p ...

, attributed to Kant. It sets out to find a "critique" on science and

metaphysics Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...

, similar to empiricism, 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 Fries who had also followed Kant's work. Although his 1904 dissertation '' Jakob Fries and his Latest Critics'' (''Jakob Friedrich Fries und seine jüngsten Kritiker'') was successful, he had trouble in his early academic years. One such failed dissertation was his ''Die kritische Methode und das Verhältnis der Psychologie zur Philosophie'' (The Critical Method and the Relationship of Psychology to Philosophy). 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. In 1922, Nelson founded the ''Philosophisch-Politische Akademie'' (Philosophical-Political Academy or PPA) as a "

Platonic Academy The Academy (Ancient Greek: Ἀκαδημία) was founded by Plato in c. 387 BC in Classical Athens, Athens. Aristotle studied there for twenty years (367–347 BC) before founding his own school, the Lyceum (classical), Lyceum. The 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, and was supported financially by the ''Gesellschaft der Freunde der Philosophisch-Politischen Akademie'' (Society of Friends of the Philosophical-Political Academy or GFA). They started working with an education center called '' Landerziehungsheim Walkemühle'', founded in 1921 by a support of Nelson, progressive teacher Ludwig Wunder (1878–1949). Although Wunder left it shortly after in 1924, educator and co-worker of Nelson, Minna Specht, took over, with the help of journalist and author

Mary Saran Maria Martha Saran (13 July 1897 – 16 February 1976), known as Mary Saran, was a journalist and author. In 1933 she emigrated from her native Germany to England, where she took British nationality and where she lived for the rest of her life. M ...

Animal rights

Nelson was an early advocate of

animal rights Animal rights is the philosophy according to which many or all sentient animals have moral worth that is independent of their utility for humans, and that their most basic interests—such as avoiding suffering—should be afforded the sa ...

and a

vegetarian Vegetarianism is the practice of abstaining from the consumption of meat ( red meat, poultry, seafood, insects, and the flesh of any other animal). It may also include abstaining from eating all by-products of animal slaughter. Vegetaria ...

. 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 book '' Animals, Men and Morals'' in 1972.

Career

Ready to form new ideas, Nelson founded the

Neo-Friesian School In late modern continental philosophy, neo-Kantianism (german: Neukantianismus) was a revival of the 18th-century philosophy of Immanuel Kant. The Neo-Kantians sought to develop and clarify Kant's theories, particularly his concept of the "thing ...

in 1903, with some well-known members, such as: * Rudolf Otto, philosopher (1869–1937) * Gerhard Hessenberg, mathematician (1874–1925) *

Otto Meyerhof Otto Fritz Meyerhof (; April 12, 1884 – October 6, 1951) was a German physician and biochemist who won the 1922 Nobel Prize in Physiology and Medicine. Biography Otto Fritz Meyerhof was born in Hannover, at Theaterplatz 16A (now:Rathenaustrass ...

biochemist Biochemists are scientists who are trained in biochemistry. They study chemical processes and chemical transformations in living organisms. Biochemists study DNA, proteins and cell parts. The word "biochemist" is a portmanteau of "biological che ...

(1884–1951) Other notable people, such as philosopher

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

and became ''

Privatdozent ''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualific ...

'' there. He later worked there as a professor from June 1919 until his death on 29 October 1927.

Internationaler Sozialistischer Kampfbund (ISK)

The ''Internationaler Jugendbund'' (International Youth Federation or IJB) was founded in 1917 by Nelson and Minna Specht. In 1918, Nelson became a brief member of the

Independent Social Democratic Party The Independent Social Democratic Party of Germany (german: Unabhängige Sozialdemokratische Partei Deutschlands, USPD) was a short-lived political party in Germany during the German Empire and the Weimar Republic. The organization was establis ...

(USPD) before becoming a member of the

Social Democratic Party The name Social Democratic Party or Social Democrats has been used by many political parties in various countries around the world. Such parties are most commonly aligned to social democracy as their political ideology. Active parties Fo ...

(SPD) from 1923–1925, when he was ultimately excluded. As a result, together with Minna Specht, he founded the Internationaler Sozialistischer Kampfbund ''(''ISK; "International Socialist Militant League") in 1925, merging it with the IJB by taking over its publishing label, ''Öffentliches Leben''. The socialist journalist Willi Eichler succeeded Nelson as president of the ISK after his death. Eichler and Specht would both sign the 1932 " Urgent Call for Unity" (''Dringender Appell für die Einheit'') in the ISK's official newspaper, '' Der Funke''. It called for Germany's

(SPD) and

Communist Party A communist party is a political party that seeks to realize the socio-economic goals of communism. The term ''communist party'' was popularized by the title of '' The Manifesto of the Communist Party'' (1848) by Karl Marx and Friedrich Engels. ...

(KPD) to create a left-wing

united front A united front is an alliance of groups against their common enemies, figuratively evoking unification of previously separate geographic fronts and/or unification of previously separate armies into a front. The name often refers to a political a ...

in order to thwart the Nazis."Dringender Appell für die Einheit"
(PDF) ''Der Funke'', No. 147 A, Berlin (June 25, 1932). Retrieved July 6, 2010 After the Nazi's defeat in 1945, the ISK was merged with the SPD with the agreement met on 10 December 1945, between the chairman of the ISK (Will Eichler) and chairman of the SPD ( Kurt Schumacher). However, the ISK continued to be active in the resistance against Nazism. A British affiliate of the ISK was created (lasted from the 1920s to the 1950s) in the United Kingdom called the

Socialist Vanguard Group The Socialist Vanguard Group was a political group active in the United Kingdom, in various guises, from the 1920s to the 1950s. While always a small organisation, its journal and some of its members became highly influential in the right wing of ...

. Among Leonard Nelson's students and political companions in the International Socialist Kampfbund were: * SPD politician Willi Eichler (1896–1971) * Prime Minister Alfred Kubel (1909–1999) * Journalist Fritz Eberhard (1896–1982), later member of the

Parlamentarischer Rat The ''Parlamentarischer Rat'' ( German for "Parliamentary Council") was the West German constituent assembly in Bonn that drafted and adopted the constitution of West Germany, the Basic Law for the Federal Republic of Germany, promulgated on ...

Personal life

Leonard Nelson was the son of

lawyer A lawyer is a person who practices law. The role of a lawyer varies greatly across different legal jurisdictions. A lawyer can be classified as an advocate, attorney, barrister, canon lawyer, civil law notary, counsel, counselor, solici ...

Heinrich Nelson (1854–1929) and

artist An artist is a person engaged in an activity related to creating art, practicing the arts, or demonstrating an art. The common usage in both everyday speech and academic discourse refers to a practitioner in the visual arts only. However, t ...

Elisabeth Lejeune Dirichlet (1860–1920), granddaughter of mathematician

Peter Gustav Lejeune Dirichlet Johann Peter Gustav Lejeune Dirichlet (; 13 February 1805 – 5 May 1859) was a German mathematician who made deep contributions to number theory (including creating the field of analytic number theory), and to the theory of Fourier series and ...

and descendant of Jewish philosopher

Moses Mendelssohn Moses Mendelssohn (6 September 1729 – 4 January 1786) was a German-Jewish philosopher and theologian. His writings and ideas on Jews and the Jewish religion and identity were a central element in the development of the ''Haskalah'', or ' ...

. Nelson married his wife, Elisabeth Schemmann (1884–1954), in 1907, but divorced in 1912 after she baptised their son Gerhard David Wilhelm Nelson (1909–1944) in the

Lutheran Church Lutheranism is one of the largest branches of Protestantism, identifying primarily with the theology of Martin Luther, the 16th-century German monk and Protestant Reformers, reformer whose efforts to reform the theology and practice of the Cathol ...

. Nelson's wife is notable for marrying Paul Hensel in 1917. His granddaughter, Maria Nelson, and Maria's daughter, Rachel Urban, both visited his grave in the summer of 1997. Although Nelson was baptised as a

Protestant Protestantism is a Christian denomination, branch of Christianity that follows the theological tenets of the Reformation, Protestant Reformation, a movement that began seeking to reform the Catholic Church from within in the 16th century agai ...

at the age of five on 13 June 1887, his refusal to baptise his son and divorce was a big change based on his Jewish ancestry. He even resigned from the Evangelical Church in 1919.

Death

He was an

insomnia Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy ...

c and died at a young age from

pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severi ...

, and was buried at a Jewish cemetery in

Melsungen Melsungen () is a small climatic spa town in the Schwalm-Eder district in northern Hesse, Germany. In 1987, the town hosted the 27th '' Hessentag'' state festival. Geography Melsungen lies on the river Fulda in the North Hesse Highlands. The stre ...

alongside his father Heinrich. Nelson's ideas continued to have an impact upon German socialism and communism in

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

as the ISK's members became active in the left-wing resistance to Nazism.

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 Georg Wilhelm Friedrich Hegel (; ; 27 August 1770 – 14 November 1831) was a German philosopher. He is one of the most important figures in German idealism and one of the founding figures of modern Western philosophy. His influence extends ...

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 Grete Hermann (2 March 1901 – 15 April 1984) was a German mathematician and philosopher noted for her work in mathematics, physics, philosophy and education. She is noted for her early philosophical work on the foundations of quantum mechanics, ...

(also part of the ISK) and Minna Specht. Some of his works are already mentioned above, but some others, available in the

Internet Archive The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge". It provides free public access to collections of digitized materials, including websites, software applications/games, music ...

(and other websites, if not available there), include: *1908 – ''Ist metaphysikfreie Naturwissenschaft möglich?'' Sonderdruck aus den ''Abhandlungen der Fries’schen Schule'', II. Bd., 3. Heft. Vandenhoeck & Ruprecht, Göttingen 1908

*1908 – ''Über das sogenannte Erkenntnisproblem''. Vandenhoeck & Ruprecht, Göttingen 190
Internet Archive
*1908 – ''Über wissenschaftliche und ästhetische Naturbetrachtung''. Vandenhoeck & Ruprecht, Göttingen 1908

*1915 – ''Ethische Methodenlehre'', by Veit & Comp., Leipzig 1915

*1917 – ''Vorlesungen über die Grundlagen der Ethik''. Veit & Comp., Leipzig ** Bd. 1: ''Kritik der praktischen Vernunft''. 1917

*1917 – ''Die Rechtswissenschaft ohne Recht: kritische Betrachtungen über die Grundlagen des Staats- und Völkerrechts insbesondere über die Lehre von der Souveränität''. Veit & Comp, Leipzig 191
Internet Archive
*1919 – ''Demokratie und Führerschaft'', Public life, Berlin 1932
Internet Archive
*1920 – ''System der philosophischen Rechtslehre''. Verlag der Neue Geist / Reinhold, Leipzig 192
Internet Archive
*1922 – ''Die Reformation der Gesinnung: durch Erziehung zum Selbstvertrauen''. The New Publishes, Leipzig 1922

*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

, Franz Oppenheimer, Minna Specht. 5th volume, Göttingen 1929, pp. 21–78.

*2011 – , a series of lectures, delivered from April to July 1921 that was omitted from his collected works. English translation

''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 house Publishing is the activity of making information, literature, music, software and other content available to the public for sale or for free. Traditionally, the term refers to the creation and distribution of printed works, such as books, newsp ...

in philosophy), in

Hamburg Hamburg (, ; nds, label=Hamburg German, Low Saxon, Hamborg ), officially the Free and Hanseatic City of Hamburg (german: Freie und Hansestadt Hamburg; nds, label=Low Saxon, Friee un Hansestadt Hamborg),. is the List of cities in Germany by popul ...

1970-1977; * 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''

Published works

* ''Ethische Methodenlehre.'' by Veit & Comp., Leipzig 1915 * ''Die Rechtswissenschaft ohne Recht.'' von Veit & Comp., Leipzig 1917. * ''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. * ''Demokratie und Führerschaft.'' Öffentliches Leben, Berlin 1932. * ''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.

References

External links

*
Biography from the SFCP site
*
A Theory of Philosophical Fallacies
' by Andrew Aberdein (in-depth review)
worldcat.org
Nelson, Leonard (1882-1927) *
Der Funke
' newspaper, 12 July 1932 – Leonard Nelson's 50th anniversary (in German)
Newspaper
by Judith Féaux de Lacroix, Melsunger edition of the '' Hessisch-Niedersächsische Allgemeine'' (28 November 2017) (in German)
"Walkemuehle -Schule des ISK"
''www.allerart.de'' (in German) {{DEFAULTSORT:Nelson, Leonard 1882 births 1927 deaths 19th-century German Jews 20th-century German mathematicians German animal rights scholars German socialists Jewish philosophers Jewish socialists Kantian philosophers University of Göttingen alumni Writers from Berlin Deaths from pneumonia in Germany Französisches Gymnasium Berlin alumni 20th-century German philosophers