I am glad of this opportunity to express my gratitude to Dr. W. Stark and Mrs. J. Robinson for the helpful criticism and appreciation with which my work has met. AGNES SCHWARZSCHILD A NOTE ON ROSA LUXEMBURG Rosa Luxemburg was born on 5 March 1870, at Zamosc, a little town of Russian Poland, not far from the city of Lublin. She came from a fairly well-to-do family of Jewish merchants, and soon showed the two outstanding traits which were to characterise all her life and work: a high degree of intelligence, and a burning thirst for social justice which led her, while still a schoolgirl, into the revolutionary camp. Partly to escape the Russian police, partly to complete her education, she went to Zurich and studied there the sciences of law and economics. Her doctoral dissertation dealt with the industrial development of Poland and showed up the vital integration of Polish industry with the wider economic system of metropolitan Russia. It was a work not only of considerable promise, but already of solid and substantial achievement. Her doctorate won, Rosa Luxemburg looked around for a promising field of work and decided to go to Germany, whose working-class movement seemed destined to play a leading part in the future history of international socialism. She settled there in 1896, and two years later contracted a formal marriage with a German subject which secured her against the danger of forcible deportation to Russia. Now, at that moment the German Social-Democratic Party was in the throes of a serious crisis. In 1899, Eduard Bernstein published his well-known work _Die Voraussetzungen des Sozialismus und die Aufgaben der Sozialdemokratie_, which urged the party to drop its revolutionary jargon and to work henceforth for tangible social reforms within the given economic set-up, instead of trying to bring about its final and forcible overthrow. This 'reformism' or 'revisionism' seemed to Rosa Luxemburg a base as well as a foolish doctrine, and she published in the same year a pamphlet _Sozialreform oder Revolution?_ which dealt with Bernstein's ideas in no uncertain fashion. From this moment onward, she was and remained one of the acknowledged leaders of the left wing within the German working-class movement. The events of the year 1905 gave Rosa Luxemburg a welcome opportunity to demonstrate that revolution was to her more than a subject of purely academic interest. As soon as the Russian masses began to move, she hurried to Warsaw and threw herself into the fray. There followed a short span of feverish activity, half a year's imprisonment, and, finally, a return journey to Berlin. The experiences of the Warsaw rising are reflected in a book entitled _Massenstreik, Partei und Gewerkschaften_, which was published in 1906. It recommends the general strike as the most effective weapon in the struggle of the proletariat against the bourgeoisie.