The ISK [Militant Socialist International] and its relationship to Vegetarianism and Esperanto

Cover page of one of the ISK's pamphlets in red ink on a white page.

An English translation of Garry Mickle's Esperanto language lecture on the history of the Internationale Sozialistische Kampfbund (ISK).

Submitted by Reddebrek on August 4, 2023

[Note; While translating the first section of Gary Mickle's text I discovered that most of the first section had already been translated into English and was being used as the English wikipedia page entry for the ISK. So I used that and translated the parts that were not in it. Section 1's Political ideas through to the end of the work is my translation. Reddebrek]

Text of a lecture for the Vegan Meeting in Castle Gresilion Paris on the 2018-05-11.


[2]Vegetarianism in the ISK: History according to End the Slaughter!

[3]ISK, Esperanto and SAT

[4] Sources

1. ISK

The Internationale Sozialistische Kampfbund (ISK) was a socialist split from the Social Democratic Party (SPD) during the Weimar Republic period, and it was active in the resistance against National Socialism (Nazism). Internationally it used the names Militant Socialist International (in English), Internationale Militante Socialiste (in French) and in Esperanto the name Internacio de Socialista Kunbatalo.


Founded in 1925 the ISK was the political organisation and platform for a circle that had gathered around the philosophy of Göttingen Leonard Nelson and his collaborator Minna Specht. It was preceded by an organization the International Socialist Youth League (ISJ) that arose in the context of the youth movement of the turn of the century, founded by Nelson and Specht in 1917 with the support of Albert Einstein. Leonard Nelson, philosophically speaking heavily tied to Neo-Kantianism- wanted to become a University Professor whose political impact surpassed the limits of the University. He was a defender of an ethically motivated, anti-clerical, anti-Marxist, but also anti-democratic oriented socialism, which included strict compulsory adherence to animal protection and vegetarianism. Nelson decided to found the ISK, after the ISJ were expelled from both the Communist Party (KPD) in 1922 and the SPD in 1925.

The ISK took over the ISYL's publishing label, Öffentliches Leben, which published the ISK newsletter beginning January 1, 1926. Beginning January 1929, an edition in Esperanto was added, and in April, a small circulation quarterly in English was added as well. It was usually eight pages and editions ran an average of 5,000 to 6,000 copies. Nelson moved his main published works there as well, his philosophical and political series Öffentliches Leben and his 1904 treatises, "Abhandlungen der Fries’schen Schule, Neue Folge", re-reasoned with mathematician Gerhard Hessenberg and physiologist Karl Kaiser, and which, after Nelson's death, was continued by Nobel Prize winner Otto Meyerhof, sociologist Franz Oppenheimer and Minna Specht until 1937.

With the growing electoral success of the Nazis at the end of the Weimar Republic, the ISK founded the newspaper, Der Funke to confront the situation. Of particular note was the "Urgent Call for Unity" (Dringender Appell für die Einheit) regarding the July 1932 federal election. It appeared in the newspaper and on placards all over Berlin. Calling for unity and support of the SPD and the KPD in order to thwart further gains by the Nazis, it was signed by 33 leading German intellectuals, including scientists Albert Einstein, Franz Oppenheimer, Emil Gumbel, Arthur Kronfeld, the artist Käthe Kollwitz, writers Kurt Hiller, Erich Kästner, Heinrich Mann, Ernst Toller and Arnold Zweig and many others.[3]

The ISK continued to work in the resistance after the 1933 Nazi ban. The ISK had destroyed all written party records and until 1938, remained undetected, while the larger parties, the KPD and SPD, were being battered by massive arrests. The ISK was therefore able to continue its resistance work, helping political refugees leave the country, conducting sabotage and distributing leaflets. In 1938, however, a wave of arrests hit the ISK.[4] A main focus of the work was the attempt to build a clandestine trade union, the Unabhängige Sozialistische Gewerkschaft ("Independent Socialist Union"), which also supported the Internationale Transport Workers' Federation.[5] The ISK's best known act of resistance was the sabotage of the opening of the Reichsautobahn on May 19, 1935. The night before Hitler's trip to inaugurate the new highway, ISK activists wrote anti-Hitler slogans, such as "Hitler = War" and "Down with Hitler", on all the bridges along the route between Frankfurt am Main and Darmstadt, where he was to travel.[6] The Nazi propaganda film produced of the event had to be edited numerous times.

In exile, the ISK also published the Reinhart Briefe ("Reinhart Letters") and Sozialistische Warte, which were then smuggled into Germany. Because of their factual and unpolemical reporting, these were valued by various members of the German Resistance. The ISK was linked with the Socialist Vanguard Group in England and the Internationale Militante Socialiste in France.
ISK members after 1945

After World War II, the ISK was merged into the SPD on December 10, 1945 after talks between Willi Eichler, chairman of the ISK and Kurt Schumacher, then chairman of the SPD. Most of the former ISK members then joined the SPD.[5]

One prominent member of the ISK, Ludwig Gehm, was later the national vice chairman of the Committee of Formerly Persecuted Social Democrats (Arbeitsgemeinschaft ehemals verfolgter Sozialdemokraten) and a Frankfurt am Main city council member from the SPD. Eichler, who was chairman of the ISK for many years, represented the SPD in the Bundestag from 1949 to 1953 and is considered one of the main authors of the Godesberg Program. Alfred Kubel was a member of the Lower Saxony state government for many years and was Ministerpräsident from 1970 to 1976. Hamburger ISK member Hellmut Kalbitzer was elected to the Bundestag several times, served in the Hamburg Bürgerschaft and from 1958 to 1962, was vice president of the European Parliament. Fritz Eberhard, who was in the ISK until 1939, was a member of the Parlamentarischer Rat ("Parliamentary Council") and was involved in writing the postwar constitution, including the right to conscientious objector status in the new laws of the Federal Republic of Germany.

Eichler also published a monthly magazine from 1946 until his death in 1971, Geist und Tat, which was devoted to "rights, freedom and culture" and he had a publishing house, Europäische Verlagsanstalt until the 1960s.


The ISK never set out to amass a large membership, but rather to become an active and hard-hitting organization. Membership requirements for prospective candidates included adherence to a certain ethical socialism that were more stringent than for the major parties.

[*]Members were to abstain from nicotine, alcohol and meat, were to be absolutely punctual and orderly, and because of the anti-clerical position of the organization, withdrawal from church affiliation was mandatory

[*]Participation in a trade union, the ISK and the labor movement was general requirement for members (eliminating passive membership)

[*]Instead of a membership fee, there was a "Party tax," which all members with an income over 150 Reichsmarks had to pay

The ISK never had more than 300 members, largely because of the strict requirements for membership. These members were organized into 32 local groups. However, its political work involved sympathizers, between 600 and 1,000 in 1933. A survey in 1929 revealed that 85% of ISK members were under 35 years of age.

Chairmen of the ISK (formerly, the ISYL)

[*]1922–1927, Leonard Nelson and Minna Specht

[*]1927–1945, Willi Eichler and Minna Specht

From 1924 to 1933, the ISK (and its forerunner, the ISYL) maintained its rural school, the Walkemühle in the Adelshausen quarter of Melsungen, Hesse and from 1931 to 1933, its own newspaper, Der Funke, both of which were banned by the Nazis.

Political Ideas

The relationship between the rank and file ISK membership and its founder and chief ideologue Leonard Nelson has been described as a “personal cult”. Nelson rejected the democratic principle, in which the majority decision is to be treated as rational. In its place he used what he called a rational-leader-principle, which has some obvious problematic elements. Nelson promoted the concept of a rational dictatorship, believing that it was possible to ascertain in an objective manner what needed to be done. The ethics of science would become the foundation of a politics of science. Nelson believed that science could show what is just, i.e. in accordance with moral law, so the rational individual who has a keen enough grasp of science will know the moral and intellectually best ways to run society they must be free from limits. An all-powerful state should carry out any and all reforms deemed necessary.

Nelson opposed the Marxist teachings of the historical necessity of capitalism to the development of socialism and communism. Instead, he promoted human responsibility and the necessity of a “moral compass”. He based these beliefs in his readings of Immanuel Kant.

Since its creation ISK was strictly anti-nationalist and anti-militarist. During the war Eichler publicly expressed opposition to the dogma of national sovereignty. The ISK also practiced sexual equality amongst its membership by promoting equality of rights for women.

The group promoted a mix of non-authoritarian and authoritarian structures within its orbit. On the one hand, its educational service Walkemühle instructed both adults and youths on the importance of critical thinking and some of the latest concepts of the time. While on the other hand, ISK described the training of civil servants as an example of authoritarianism.

2. Vegetarianism in the ISK and the anti-Fascist Resistance

As described, a vegetarian way of life was a mandatory membership condition in ISK. Through its publications it propagated vegetarianism in Germany and abroad. It organized group visits in slaughterhouses to convince the workers to renounce their work and the other violent ways humans relate to animals. Willi Eichler ISK co-president since 1927 documents one of these visits in his 1926 essay “Even Vegetarians?” Recently that essay has been circulated again by social democrats acting in the group Sozis für Tiere (Social Democrats for animals). Willi Eichler would join the SPD in the aftermath of the Second World War and moderate his politics. He led the commission that developed the social democratic Program of Godesberg (accepted in 1959), in which the idea of socialism appeared only in a very diluted form, and which many later regarded as a road map for the right-wing in that party. I could not find out if he remained a lifelong vegetarian.

Nelson agreed with Eichler: "A worker who wishes more than a guarantee he will not become a capitalist and for whom the fight against all exploitation is a serious matter, he does not bow before the pressure of public opinion toward the habit of exploiting harmless animals, he does not participate in the daily millionfold murder."

The resistance activity of the ISK against the Nazi rule was effective, if we consider the enormous difficulties and the small membership. Cunning means were applied, and one of them made use of vegetarianism - more on that later.

At the beginning of Nazi rule, the ISK formulated 4 objectives for resistance activity: information, propaganda, anti-Nazi actions, and security for the group. One means was illegal leafleting. The Nazis held elections of worker representatives in companies, admitting only "suitable" candidates. The ISK campaigned for a vote of no confidence against all candidates - until the Nazis gave up on the elections in 1936 due to the lack of popular support for their picked candidates. (Only 50-60% voted for the official list.) Also in 1936, ISK members also collected money in workplaces for the resistance in Spain.

At the inauguration of a highway, it was discovered that the bridges were painted overnight with chemicals that can be seen only when daylight hits them, and the speaker systems had been sabotaged. Two SS members were later executed for insufficient vigilance. Invisible paint, which is visible in daylight, was also used for to daub slogans on the pavement, using suitcases with a special mechanism. A grassy hill next to the Berlin railway was chosen for an action using fertilizer poured from canisters. After a few weeks the hill was marked with the slogan "Nieder mit Hitler" [Death to Hitler].

The ISK also discussed a plan to kill Hitler via a suicide attack, but the plan was opposed by some members and did not go beyond discussions.

The anti-Nazi activity included a set of vegetarian restaurants, which ISK members operated in several cities and used for clandestine purposes. Some had opened before 1933, the remainder opened after the rise to power from the Nazis. Large restaurants were founded in Berlin, Hamburg, Frankfurt am Main and Bochum. According to one report, the Hamburg restaurant prepared 120 lunches a day.

They were often led by women, but both men and women worked in them. The working day was long and the pay low. The restaurants served several purposes: to provide work to the unemployed, to generate a profit that was used for resistance activity, enable contact between resistance agents in a relatively unsuspicious place, serve as bases for production and distribution of illegal printing material etc. However, they also served for promote vegetarianism.

A wave of arrests in 1937 forced many restaurant workers to flee abroad or to live in hiding. Two fugitives founded vegetarian restaurants in Paris and London. The restaurant in Paris became a contact point for exiled Germans and was also a source of funds. The same for the restaurant in London. There they were supported by a group linked to Nelson inside the Labour Party, the Socialist Vanguard Group, the British affiliate to the Militant Socialist International (ISK).

Here is a somewhat extensive quote from a document from the City Archives of Göttingen, which captures the atmosphere of the era and also paints a picture of the spread of vegetarianism in Germany at the time and the political implications of it, e.g. the spread of the legend about Hitler being “Vegetarian”:

Next to the premises of the ISK in the city, the vegetarian restaurant can be seen, operated by the mother of Fritz and Helmut Schmalz on Weenderstraße 71/72. August Schmalz was member in the ISK since 1927; she had already led vegetarian cooking courses in the Walkemühle. Vegetarian restaurants were a financial pillar of the organization, although more profitable and useful for that purpose were the restaurants in the bigger cities like Berlin, Hamburg (Anna Kothe worked there since 1934, who for a long time worked in the headquarters in Göttingen as a housekeeper), Cologne or Frankfurt. Auguste Schmalz's vegetarian luncheonette has been around since at least 1931 and was a regular meeting place. Hannah Vogt recalled: “I remember a place in Weender Straße – which was led by the mother of trade unionist Fritz Schmalz – where everyone had a vegetarian lunch. Many of them regularly met there.” Since spring of 1933 the premises were observed, however the police failed to prove that the guests of the Schmalz lunchroom participated in anti government discussions.

The income opportunities that opened up with such a restaurant also attracted the greedy gaze of the "Volksgenossen" [Nazi term, roughly means People’s comrades, used as a term for correct i.e. Nazi behaviour]. In a letter to the rector of the university at the end of October 1933, someone proposed a remedy against an urgent lack of food for the students. He said that among the 4,000 students there are at least 150 vegetarians, "who now wish to live according to the way of life of our people's chancellor", but can't, because "the only vegetarian lunch place here (...) is run by the ex-communist Schmalz". According to the writer, he even makes an advertisement by posting it on the blackboard of the auditorium, despite the fact that it is possible to prove, "that the students are being influenced by propaganda there, acting at that in a very refined manner”. The author of the letter thought his “most noble task to provide the students of the University of Göttingen with the cheapest high-quality food, in accordance with the new theory of nutrition". Of course he hoped for the support from the rector for his "valuable idea, also represented by Hitler, Rudolf Hess, Göbbels (!) and even many professors in Göttingen". Schmalz's lunchroom survived despite these attacks and denouncements at least until the beginning of the war.

3. ISK, Esperanto and SAT

The ISK attempted to spread beyond the borders of Germany in their early days and adopted Esperanto as one of the means to achieve this.

Registered in bibliographies is the edition of the quarterly Esperanto-language Organo de Internacio de Socialista Kunbatalo since 1929 (before the appearance of a similar publication in English). After the Autumn of 1933 it appeared in Paris under the name The Critical Observer: magazine of politics and culture. It continued to be published until the end of 1939 if not longer. Hermann Platiel was credited as its editor after the move to Paris, but its possible that he occupied that position earlier.

The ISK published a daily newspaper Der Funke [The Spark] for 14 months, between 1932-01-01 and 1933-02-17. Then it was banned. The release necessitated great sacrifices, inevitable for such a small organization. Notable in it is the striving for a working class united front against the looming fascism and the very critical reporting on nationalism in general. The complete journal collection is now archived online. There you can find three kindly written articles about SAT and its congress from 1932 in Stuttgart. Although one would expect that their author would be Hermann Platiel, the authors used initials ("M. H.", "Rpt.", "O. W.") do not match that assumption.

Some excerpts from the articles:

Party political neutrality among the Worker Esperantists (from Der Funke 1932-06-05) In the Esperanto Labour movement, whose most important, global organization is SAT (World Anti-national Association), the party political disputes, especially between the CP and the SP, was not missing. In Germany there are already in many cities separate communist and social democratic Esperanto groups. All the more gratifying that the president of SAT, Lanti, who also publishes the Esperanto newspaper Sennaciulo, stands entirely on the ground of the party political neutrality of SAT. In an open letter to many SAT members he assumes a position against the communist attempts to link SAT to a definite political program, by which the CP wants to secure for itself a better foundation for its domination. The CP wants first, that SAT compels all members to recognize Marxism as “the correct basis on which the firm unity of the proletarian Esperantists can be founded".


In addition, Lanti quite rightly throws back the opinion that non-Marxist viewpoints such as those of Nelson, Kropotkin or Gesell should remain undiscussed in the newspaper, because "the vast majority of organized workers recognize Marxism as the theoretical basis for their class struggle”. That is totally incorrect - let's think about England, Spain or India!


It is desirable that Lanti's positions continue to be guiding SAT and its newspaper, so that the very desirable propaganda for Esperanto as an international means of understanding, especially as a tool for a fighting working class should not be hindered by a dogmatic and party-politically narrow framework.

We greet the Esperantists in Stuttgart [title originally in Esperanto] (from Der Funke 1932-08-06) In the second week of August, the 12th congress of ... SAT meets in Stuttgart. […]

SAT for two reasons is particularly called to work on the creation of the socialist united front: Its members are linked by the bond of a common language. […] SAT also fulfills an important prerequisite for the collaboration in the creation of united front of the various workers parties. The management of SAT has been resisting firmly and successfully for years against the disrespect of party political neutrality within the Association. [...]

The working Esperantists in Stuttgart (from Der Funke 1932-09-01) The 12th congress of the world association of working Esperantists (SAT) 250 comrades from 12 countries participated despite the bad economic situation.


The most important result of the congress was the re-securing of the party political neutrality of SAT.


Also the efforts to change the current structure of SAT – a union of all the proletarian Esperantists without regard to their nationality or race - by associating national associations, were unanimously rejected.

With the exception of the proposers, all the comrades emphasized the necessity right now, of a front between the workers and the growing wave of nationalism, not only emphasizing the international connectedness of the proletariat, but also to practically realize it, for which purpose the present stateless organizational form offers the best basis.


Its known that Hermann Platiel was both an ISK and SAT member. Born in 1896 (or possibly 1886) and died in 1980, Platiel was hired as an administrator for the SAT office in Leipzig from the 8th of May 1929 until 1932. In Leipzig he also led the local ISK branch. After Lanti stood down from the post it was Platiel who became the President and Director of SAT from 1933-35. SAT published his text History of the schism in the Workers Esperanto-Movement: Documentation which shows the causes and responsibilities and prepares the foundation for united action. He then became the secretary of the French Esperanto section of ISK 1938-39. I do not know if he has been active in SAT since the 40s or maintained any relationship with Esperanto at all. Petro Levi who joined SAT shortly after the war does not remember seeing him when I asked, and I was not able to find anything online, though of course there are still other sources to check,

In 1943 he illegally fled to Switzerland, and worked for the "Schweizer Hilfswerk" (Swiss Relief Fund) and wrote reports for the London foreign leadership of ISK. Before the escape to Switzerland he was located in the southern French city of Montauban, to which he fled from the internment camp in Gurs. There he married with well-known ISK member Nora Platiel (née Block). In 1949 they settled in the German city of Kassel, where Nora began a career as a court jurist and then a representative of the Hesse parliament (for the SPD). Hermann worked as a director of a theatre in Kassel, according to reports with great commitment.

This summary of facts about ISK's relations with Esperanto and especially with SAT is very incomplete. Further research would be worthwhile. Research in the archive of SAT in Paris should provide insights about that, also about Hermann Platiel personally, and would answer the question whether he and possibly others ISK members played a role in the then Vegetarian Section of SAT, which we can guess, but do not know now.

4. Sources

• Das Schlachten beenden!, Verlag Graswurzelrevolution, Nettersheim 2010 [GWR estas

monata ĵurnalo kaj eldonejo dediĉitaj al senperforta anarkiismo, kun ekologia emfazo kaj

simpatianta kun veganismo; pli ĉe]

• Heiner Lindner: Um etwas zu erreichen, muss man sich etwas vornehmen, von dem man

glaubt, dass es unmöglich sei – Der Internationale Sozialistische Kampf-Bund (ISK) und

seine Publikationen, Friedrich-Ebert-Stiftung 2006,


• Vikipedio germanlingva: ISK, Nora Platiel kaj esperantlingva pri Hermann Platiel

• urba arkivejo de Göttingen:


Gary Mickle

Translated into English by Reddebrek



8 months 1 week ago

Submitted by Entdinglichung on August 4, 2023

thanks for posting this, some sources indicate that the ISK demanded during the 1920ies from its leading members also celibacy ... after 1945, most ISK members became pretty normal social democrats, luckily the former members who ran the publishing house Europaeische Verlagsanstalt (EVA) stayed solidly on the left and EVA became an important left-wing institution which made around 1968 e.g stuff by Rosdolsky, Korsch, Luxemburg, Trotzki, Bauer, etc available in cheap editions

a successor of the ISK: