"In Rosa Luxemburg, the socialist idea was a truly burning passion. The great duty and indomitable ambition of this remarkable woman was to prepare the way for social revolution, to open the path of history for socialism, with a will, determination, selflessness, and dedication that words are too weak to describe... She gave herself completely to the cause of socialism, not only with her tragic death, but with her entire life... She was the sharp sword and the living flame of revolution."
Clara Zetkin, 1919

"Being the embodiment of the unity of theory and practice, the life and work of Rosa Luxemburg would require a description of both her actions and her thoughts. However, in the context of a small book, one cannot hope to do justice to both. Therefore, necessarily, I focus mainly on her ideas, as they contain her main and lasting contribution to the international socialist movement.
"Dare to question everything" was Rosa Luxemburg's motto. She could not wish for anything better than a critical evaluation of her work. That is why this book was written with a spirit of admiration, but also with criticism of the subject it examines."
Tony Cliff, 1959