Experimentation is, properly speaking, nothing more than the decomposition of a phenomenon into its elements. One removes them in succession, and observes what is lacking, in order to identify the role of each of these elements in the total production of the phenomenon.

Translated by Hebbel H. Hoff, Lucienne Guillemin and Roger Guillemin, The Cahier Rouge of Claude Bernard (p. 36), Schenkman Publishing Co. 1967