There can be nothing more abominable than religion.

If Socialism can only be realized when the intellectual development of all the people permits it, then we shall not see Socialism for at least five hundred years.

We would be deceiving both ourselves and the people if we concealed from the masses the necessity of a desperate, bloody war of extermination, as the immediate task of the coming revolutionary action.

To rely upon conviction, devotion, and other excellent spiritual qualities; that is not to be taken seriously in politics.

Pacifism, the preaching of peace in the abstract, is one of the means of duping the working class.

It is necessary to be able to withstand all this, to agree to any and every sacrifice, and even - if need be - to resort to all sorts of stratagems, manoeuvres and illegal methods, to evasion and subterfuges in order to penetrate the trade unions, to remain in them, and to carry on Communist work in them at all costs.

Unity is a great thing and a great slogan. But what the workers’ cause needs is the unity of Marxists, not unity between Marxists, and opponents and distorters of Marxism.