“Apart from its effect on the war, the Revolution was in itself a tremendous event, unique in world history. Although it was the first revolution of its kind, it may not long remain the only one of its type, for it has become a challenge to other countries and an example for many revolutionaries all over the world… The March Revolution had been a spontaneous unorganized one, the November one had been carefully planned out. For the first time in history the representatives of the poorest classes, and especially of the industrial workers, were at the head of a country.”

Pt. 1, 7
Social Insurance and Allied Services (1942)
Context: Any proposals for the future, while they should use to the full the experience gathered in the past, should not be restricted by consideration of sectional interests established in the obtaining of that experience. Now, when the war is abolishing landmarks of every kind, is the opportunity for using experience in a clear field. A revolutionary moment in the world’s history is a time for revolutions, not for patching.

August 19, 1914. Quoted in "A Shameful Act: The Armenian Genocide and the Question of Turkish Responsibility" - by Taner Akcam - History - 2007 - Page 132.

Words to Intellectuals (1961)

Tactics and Strategy of the Latin American Revolution (1962)
Context: The most submissive countries and consequently, the most cynical, talk about the threat of Cuban subversion, and they are right. The greatest threat of the Cuban revolution is its own example, its revolutionary ideas, the fact that the government has been able to increase the combativity of the people, led by a leader of world stature, to heights seldom equaled in history. Here is the electrifying example of a people prepared to suffer nuclear immolation so that its ashes may serve as a foundation for new societies. When an agreement was reached by which the atomic missiles were removed, without asking our people, we were not relieved or thankful for the truce; instead we denounced the move with our own voice. We have demonstrated our firm stand, our own position, our decision to fight, even if alone, against all dangers and against the atomic menace of Yankee imperialism.

Source: Letter to Ludwig Kugelmann (28 December 1862), quoted in The Collected Works of Karl Marx and Friedrich Engels: Volume 41. Letters 1860–64 (2010), p. 437

Les silences du colonel Bramble (The Silence of Colonel Bramble)

"Concerning the production of Consciousness"
The German Ideology (1845/46)

Source: Russia Under The Bolshevik Regime (1994), p. 262