SummaryAfter exposing certain confusions (between epistemological and ontological points of view, between two levels of the given, between that which represents and that which is represented, between elements and relations), 1 give a sketch of a non‐metaphysical realism which involves the construction of a world‐O, mainly by means of criteria of invariance and of independence of variables.This world‐O facilitates description of the relationships of sensations among themselves and with actions. It includes the subject objectivized with his subjectivity (subject‐O), which makes it possible to describe without difficulty the relationship (of a causal nature) between this subject and the world. This realism reconstructs as it were realism from an idealist standpoint, but allows for all the distinctions characteristic of realism: between illusion and reality, between that which represents and that which is represented, etc. Finally, the world‐O is not its own standard: the sensations for which it makes prediction are compared with those that are actually perceived, thus allowing its appropriateness to be