“[Letter to his wife, Natalia Sedova]In addition to the happiness of being a fighter for the cause of socialism, fate gave me the happiness of being her husband. During the almost forty years of our life together she remained an inexhaustible source of love, magnanimity, and tenderness. She underwent great sufferings, especially in the last period of our lives. But I find some comfort in the fact that she also knew days of happiness.For forty-three years of my conscious life I have remained a revolutionist; for forty-two of them I have fought under the banner of Marxism. If I had to begin all over again I would of course try to avoid this or that mistake, but the main course of my life would remain unchanged. I shall die a proletarian revolutionist, a Marxist, a dialectical materialist, and, consequently, an irreconcilable atheist. My faith in the communist future of mankind is not less ardent, indeed it is firmer today, than it was in the days of my youth.Natasha has just come up to the window from the courtyard and opened it wider so that the air may enter more freely into my room. I can see the bright green strip of grass beneath the wall, and the clear blue sky above the wall, and sunlight everywhere. Life is beautiful. Let the future generations cleanse it of all evil, oppression and violence, and enjoy it to the full.”

“Life is not an easy matter... You cannot live through it without falling into frustration and cynicism unless you have before you a great idea which raises you above personal misery, above weakness, above all kinds of perfidy and baseness.”

“Old age is the most unexpected of all things that happen to a man.”

“The depth and strength of a human character are defined by its moral reserves. People reveal themselves completely only when they are thrown out of the customary conditions of their life, for only then do they have to fall back on their reserves.”

“The historic ascent of humanity, taken as a whole, may be summarized as a succession of victories of consciousness over blind forces - in nature, in society, in man himself.”

“There are no absolute rules of conduct, either in peace or war. Everything depends on circumstances.”

“Not believing in force is the same as not believing in gravitation.”

“City of prose and fantasy, of capitalist automation, its streets a triumph of cubism, its moral philosophy that of the dollar. New York impressed me tremendously because, more than any other city, it is the fullest expression of our modern age.”

“‎The party that leans upon the workers but serves the bourgeoisie, in the period of the greatest sharpening of the class struggle, cannot but sense the smells wafted from the waiting grave.”

“In a country where the sole employer is the State, opposition means death by slow starvation. The old principle: who does not work shall not eat, has been replaced by a new one: who does not obey shall not eat.”

“Old age is the most unexpected of all the things that can happen to a man.”