Rules for the Distinction of the Normal from the Pathological

Abstract

Observation conducted according to the preceding rules mixes up two orders of facts, very dissimilar in certain respects: those that are entirely appropriate and those that should be different from what they are — normal phenomena and pathological phenomena. We have even seen that it is necessary to include both in the definition with which all research should begin. Yet if, in certain aspects, they are of the same nature, they nevertheless constitute two different varieties between which it is important to distinguish. Does science have the means available to make this distinction?