Between 1898 and 1904 two socialists who agreed on almost nothing received the same objection from the same critic. Eduard Bernstein, a senior German Social Democrat, had argued that capitalism was not heading for collapse and that his party should settle for reform through trade unions and parliament. Lenin, who led one side of the divided Russian Social Democrats, wanted a party whose central committee would form the local committees and direct their work. Rosa Luxemburg answered Bernstein in Reform or Revolution (1899) and Lenin in the article "Organizational Questions of Russian Social Democracy" (1904). Each man, she argued, had put someone else in the place of the workers: deputies and union officials in the first case, a committee in the second. Socialism can be made only by the mass of working people themselves, who learn how to do it by acting, and no parliament or party leadership can do it on their behalf.
She grew up in Warsaw, in a Jewish family in the part of Poland that Russia ruled. In 1889, threatened with arrest for her politics, she was smuggled over the border and went to Zürich, where she took a doctorate in 1897 with a thesis on the industrial development of Poland. Polish industry had grown into the Russian market, she argued, so an independent Poland was no aim for socialists, and the Polish party she had helped to found in 1893 refused to demand one. In April 1898 she married a German, Gustav Lübeck, to obtain his citizenship. In May she moved to Berlin and joined the Social Democratic Party, and by September she was writing against Bernstein.
Events in Russia then gave her evidence that workers learn by acting. In December 1905 she went to Warsaw to take part in the revolution that had spread across the Russian empire that year; she was arrested in March 1906 and held into the summer. The Mass Strike, the Political Party and the Trade Unions (1906) sets out what she had learned. The strikes had not been planned by anyone. Workers who belonged to no union struck first and built their unions afterwards, and strikes over wages kept turning into strikes against the government. Organisation, she concluded, grows out of the struggle, and a party can neither order a mass strike nor forbid one. The German party decided otherwise. Its congress at Mannheim in September 1906 agreed to call no mass strike without the trade unions, and in 1910 the same dispute ended her alliance with Karl Kautsky, the party's leading theorist.
From 1907 she taught economics at the party's school in Berlin, and a difficulty she met while writing up her lectures became The Accumulation of Capital (1913). Marx had drawn up tables in which a society of capitalists and workers grows year after year, and Luxemburg asked who buys the growing surplus of goods. Her answer was that the buyers must come from outside capitalism, from peasants, craftsmen and colonies, and that capital destroys these economies as it absorbs them. Imperialism, on this account, is the way growth continues, and it has a limit because the outside world is finite.
On 4 August 1914 the Social Democratic deputies voted for the credits that paid for Germany's war. Luxemburg spent most of the war in prison: a year in Berlin from February 1915 for an anti-war speech, then, from July 1916 to 9 November 1918, detention without trial in the fortress at Wronke and in Breslau. In the Berlin prison she wrote the Junius Pamphlet (1916), published in English as The Crisis in the German Social-Democracy. It told her party that society must either go forward to socialism or fall back into barbarism, and that the war was the falling back.
In Breslau, in the autumn of 1918, she wrote The Russian Revolution, an unfinished manuscript that defends Lenin's party for taking power and criticises it for dissolving the elected assembly and restricting the vote, the press and the right of assembly. This was her objection of 1904, now addressed to a government. Socialism cannot be introduced by decree, she argued, because no one holds the plan in advance. It has to be learned in open public life, and so freedom must be the freedom of the person who thinks differently.
Her group, which had taken the name Spartacus in 1916, helped to found the Communist Party of Germany at the end of December 1918. At the founding congress she argued that the party should stand in the national elections, and lost the vote, 62 to 23. Two weeks later government troops put down a rising in Berlin. On 15 January 1919 she and Karl Liebknecht, who led the Spartacus group with her, were arrested and handed to soldiers of a cavalry division, who killed them both.
Paul Levi, her lawyer, printed the Russian manuscript in 1922, and Lenin replied that year by listing her errors and calling her, in spite of them, an eagle. In 1925 Grigory Zinoviev, who chaired the Communist International, called for a campaign against "Luxemburgism". In 1988 East Germany arrested opposition activists who quoted her sentence on freedom at a demonstration. The Accumulation of Capital had been rejected by almost all its socialist reviewers, and by Lenin. But its English translation of 1951 carried an introduction by the Cambridge economist Joan Robinson.