“The meaning of life is life itself.”

From Critique of Everyday Life: Volume 1 (1947/1991)
Context: The 'meaning' of life is not to be found in anything other than that life itself. It is within it, and there is nothing beyond that. 'Meaning' cannot spill over from being; it is the direction, the movement of being, and nothing more. The 'meaning' of a proletarian's life is to be found in that life itself: in its despair, or conversely in its movement towards freedom, if the proletarian participates in the life of the proletariat, and if that life involves continuous, day-to-day action (trade-union, political...).

Things I Didn't Know (2006)

Henry Miller on Writing (1964)

Wonders of the Universe - Messengers

Letter to Cecil Spring-Rice (12 March 1900)
1900s

Kulturphilosophie (1923), Vol. 2 : Civilization and Ethics
Context: Reverence for life, veneratio vitæ, is the most direct and at the same time the profoundest achievement of my will-to-live.
In reverence for life my knowledge passes into experience. The simple world- and life-affirmation which is within me just because I am will-to-live has, therefore, no need to enter into controversy with itself, if my will-to-live learns to think and yet does not understand the meaning of the world. In spite of the negative results of knowledge, I have to hold fast to world- and life-affirmation and deepen it. My life carries its own meaning in itself. This meaning lies in my living out the highest idea which shows itself in my will-to-live, the idea of reverence for life. With that for a starting-point I give value to my own life and to all the will-to-live which surrounds me, I persevere in activity, and I produce values.

146
Multitude: War and Democracy in the Age of Empire

Source: book Man's Search For Meaning