The full text of "The Mass Strike" and "Reform or Revolution", two of the most important essays by this contemporaneous Marxist critic of Leninism. Rosa Luxemburg was a leading and visionary socialist in Germany in the early twentieth century. Her insistence that ordinary working people could win not only battles for improvements in their day-to-day conditions of life, but also the most important battle of all—the fight to create a society based on justice and equality—distinguished her among other leading socialists." "This insightful new introduction to Luxemburg's two most important works presents the full text of Reform or Revolution and The Mass Strike, with explanatory notes, appendices, and introductions. These two essays offer a persuasive Marxist analysis on the decisive questions of Luxemburg's era: Can capitalism ever be refined into a just system or must it be replaced root and branch? And what kind of struggle from below is needed to achieve such a transformation?