Cubism is no different from any other school of painting. The same principles and the same elements are common to all. The fact that for a long time cubism has not been understood and that even today there are people who cannot see anything in it, means nothing. I do not read English, and an English book is a blank to me. This does not mean that the English language does not exist, and why should I blame anyone but myself if I cannot understand what I know nothing about?

p. 319. - "Picasso Speaks," 1923