Realism's 'truth' as embodied in painting and literature now solely consists of things capable of being seen by the eye or heard by the ear. Realism is concerned only with the external shell of nature. People content with the discoveries they have made ignore the fact that there are other things to be discovered, even broader avenues to be explored. They have found bacteria, but not what they consist of.

OKK 1760 (Nice, January 1892); as quoted in Edvard Much – behind the scream, Sue Prideaux; Yale University Press, New Haven and London, 2007, p. 81