Abstract EN:

Until the XVIth century, the notion of interest is nearly non existent in the representations of the world and of action. From the XVIth century and during all the XVIIth, it enlarges its uses as far as it becomes the notion we can't avoid nor refute nowadays. Through the study of its most important promoters, from Guichardin to Leibniz, and assuming that its introduction provides a solution that enables them to work out new problems they have to face, this work shows that the notion of interest is not a psychological motivation that would lead to the representation of a selfish man nor to the mere introduction of the utilitarian paradigm. The analysis of its uses (whether it's used to solve economic, moral or political problems), of its objects and subjects, of its qualities (either descriptive or normative, either particular or general) and of its ambivalent effects (utility, prejudice), enables to show that its stake is wider, in so far as the modelling of the reality is concerned. Interest works as a principle of action, as a corrective variable. It allows to get the phenomenons under control, to get a phenomenal representation of the relationships between the man and his world around. Its extension leads to an upgrading of tangible world, that gives the representation of value a new start, and appraises them throughout concurrence. Therefore, it takes part in the construction of modernity.