This book was written by Leon Trotsky at the height of the Russian Civil War. While it is a polemical response to German social-democrat Karl Kautsky, it is also represents the Bolshevik defence of the extraordinary means the young workers’ republic had to take in order to defend itself from the almost two dozen armies that were on its soil trying to turn back the revolution. This version keeps true to the form of the style of English used in this edition of the book, with only some spelling corrections and the contemporary title, Terrorism or Communism.

Ever since it was born, Marxism has had to wage a continual war to free itself of ultraleftism and opportunism. Marx and Engels waged a stubborn struggle against the ultraleft Bakunin. And the whole history of Bolshevism was a history of sharp ideological battles. Lenin was obliged more than once to combat ultraleft tendencies within the ranks of Bolshevism – for example after the defeat of the 1905 Revolution, when he found himself in a minority in the leadership on the question of the need to participate in elections to a rigged tsarist parliament and work in the trade unions and other legal and semi-legal organizations.

Lenin began work on the book The Proletarian Revolution and the Renegade Kautsky at the beginning of October 1918, immediately after he had read Kautsky’s The Dictatorship of the Proletariat, which distorted and vulgarised the Marxist theory of the proletarian revolution and slandered the Soviet state. Lenin attached great importance to exposure of Kautsky’s opportunist views on the socialist revolution and the dictatorship of the proletariat.

Leon Trotsky's History of the Russian Revolution to Brest-Litovsk was written at the Brest-Litovsk peace conference a mere few months after the Bolsheviks had come to power. It gives an excellent introduction to the history of the Russian Revolution.

Written in the summer of 1917, in the heat of the Russian Revolution, Lenin’s State and Revolution is a key work of Marxism. Here, Lenin explains that, stripped of all non-essentials, the state is in the final analysis “groups of armed men”: the army and the police, in defence of the ruling class.

Lenin's masterpiece Imperialism is an immortal monument to his work in the vital field of theory. No book has ever explained the phenomenon of modern capitalism better. Indeed, all of Lenin’s predictions concerning the concentration of capital, the dominance of the banks and finance capital, the growing antagonism between nation states and the inevitability of war arising out of the contradictions of imperialism have been shown to be true by the entire history of the last 100 years.

Lenin decided to write the pamphlet Socialism and War (The Attitude of the R.S.D.L.P. Towards the War) in connection with the preparations for the First International Socialist Conference. G. Y. Zinoviev helped write the pamphlet, though most of it was drawn up by Lenin, who, moreover, edited the entire text. The pamphlet was published in German in September 1915 and distributed among the delegates to the Zimmerwald Socialist Conference. 

Rosa Luxemburg was the most eloquent voice of the left wing of German Social Democracy and a constant advocate of radical action. She spent much of the war in jail, where she wrote and then smuggled out this pamphlet. Published under the name “Junius”, a pseudonym used by an influential English pamphleteer in the 18th century, the pamphlet became the guiding statement for the International Group, which became the Spartacus League and ultimately the Communist Party of Germany. Luxemburg was instrumental in these developments and, along with Karl Liebknecht, led the Spartacists until their assasination by the German government on January 15, 1919.

This pamphlet was written in 1914 during Trotsky’s two month stay in Zurich. He had arrived there rather hurriedly from Vienna which he left on the evening of August 3rd, the day Germany declared war against France. ”Written in extreme haste,” Trotsky says in his preface, “under conditions far from favourable to systematic work... the entire book, from the first page to the last, was written with the idea of the New International constantly in mind – the New International which must rise out of the present world cataclysm, the International of the last conflict and the final victory.”

"Complete equality of rights for all nations; the right of nations to self-determination; the unity of the workers of all nations—such is the national programme that Marxism, the experience of the whole world, and the experience of Russia, teach the workers." The classic theoretical work on the national question by Lenin.

This short article outlines the most basic—but fundamental—elements of Marxism: its philosophy, understanding of history, and analysis of economics.

In this little book Connolly challenges the nationalist myths about the Irish struggle for freedom from British rule. Connolly’s aim was to convince the radical nationalists that their policy of a ‘union of classes’ would lead to disaster. He argued that Irish independence would bring little in the way of freedom and progress for the majority of the Irish people unless it included a fundamental challenge to the structure of society. He also shows graphically how the Irish capitalist class was always prepared to abandon and betray the struggle for liberation if its economic and social interests were threatened.

"No book can eradicate religion from the minds of masses who are crushed by capitalist hard labour, and who are at the mercy of the destructive forces of capitalism, until those masses themselves learn to fight this root of religion, fight the rule of capital in all its forms, in a united, organised, planned and conscious way. Does this mean that educational books against religion are harmful or unnecessary? No, it means that Social-Democracy’s atheist propaganda must be subordinated to its basic task—the development of the class struggle of the exploited masses against the exploiters."

Early Christianity arose at a time of upheaval and change associated with the crisis of slave society. The rise of Christianity is one of the most extraordinary phenomena in history. Kautsky's Foundations of Christianity deserves a far wider audience than it has had. The main conclusions have been strikingly confirmed by the latest discoveries of archaeology and in particular the Dead Sea Scrolls. As such, Kautsky’s book remains a masterpiece of the method of historical materialism.

Rosa Luxemburg's Reform or Revolution was one of the most important of her early writings. Written in 1899, it provides a devastating demolition of the theoretical and practical basis of reformism. It was completely valid at the time when it was written and it remains completely valid today. This work placed herself amongst the foremost leaders of the left of Social Democracy internationally, a role she was to occupy until her assassination in 1919.

Trotsky’s theory of the permanent revolution is one of the most important additions to the arsenal of Marxism. It was first developed by Trotsky in 1904, on the eve of the first Russian Revolution. At that time, all the tendencies of the Russian Social Democracy had the perspective of a bourgeois democratic revolution. Trotsky alone in 1905 put forward the idea that the Russian working class could come to power before the workers of Western Europe. The correctness of Trotsky’s theory was brilliantly demonstrated in 1917, when the Bolshevik Party under Lenin and Trotsky led the Russian proletariat to power in the first workers state in the world.

"Here is the answer to all the attacks of the clergy: the Social-Democracy in no way fights against religious beliefs. On the contrary, it demands complete freedom of conscience for every individual and the widest possible toleration for every faith and every opinion. But, from the moment when the priests use the pulpit as a means of political struggle against the working classes, the workers must fight against the enemies of their rights and their liberation." (Luxemburg)

First published in early 1902, What Is to Be Done? remains a classic of Marxism on the building of the revolutionary party, which sets out the party’s role as the organiser and director of the revolution. The pamphlet was written as part of a conflict with the opportunism of the Economists, who emphasised ‘bread and butter issues’ rather than theory. Lenin uses the book to explain the necessity of creating a centralised group of professional and dedicated revolutionary cadres before the “times of explosion and outbursts.” The history of the past 100 years has proven Lenin right: time and again, the masses have been ready to struggle, but let down by their leadership.

Lenin's famous call to arms makes the case for a disciplined revolutionary party, organised around an “All-Russian” political newspaper. Through the aid of a newspaper “a permanent organisation will naturally take shape that will engage, not only in local activities, but in regular general work, and will train its members to follow political events carefully, appraise their significance and their effect on the various strata of the population, and develop effective means for the revolutionary party to influence these events.”

Ever since Engels' arrival in London in 1870, he was keen to write a comprehensive work on science and dialectical materialism. The notes and studies for such a work make up the present volume, originally published in 1925. It is an essential read for all those who want to develop a deeper understanding of Marxist philosophy.