- [A]ny musician who has not experienced - I do not say understood, but truly experienced - the necessity of dodecaphonic music is USELESS. For his whole work is irrelevant to the needs of his epoch.
- Emphasis in the original. From "Eventuellement..." (1952), translated as "Possibly..." in Stocktakings from an Apprenticeship, Oxford: Oxford University Press, 1991, p.113. ISBN 0193112108
- Creation exists only in the unforeseen made necessary.
- From "Eventuellement..." (1952), translated as "Possibly..." in Stocktakings from an Apprenticeship, Oxford: Oxford University Press, 1991, p.133 ISBN 0193112108
- Stupid, stupid, stupid!
- On the music of Giuseppe Verdi. Quoted in Boulez: Composer, Conductor, Enigma by Joan Peyser, New York: Schirmer Books, 1976.
- Proceeding from the simple fact that I think, I tried to find out how a musical language could be built from scratch.
- The most elegant way of solving the opera problem would be to blow up the opera houses.
- The aim of music is not to express feelings but to express music. It is not a vessel into which the composer distills his soul drop by drop, but a labyrinth with no beginning and no end, full of new paths to discover, where mystery remains eternal.
- Revolutions are celebrated when they are no longer dangerous.