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.
Vladimir LeninUnity must be won, and only the workers, the class-conscious workers themselves can win it - by stubborn and persistent effort.
Vladimir LeninYou have read and heard that communist theory-the science of communism created in the main by Marx, this doctrine of Marxism-has ceased to be the work of a single socialist of the nineteenth century, even though he was a genius, and that it has become the doctrine of millions and tens of millions of proletarians all over the world, who are applying it in their struggle against capitalism.
Vladimir Lenin