In this paper, we investigate how the life and work of Louis Rougier relate to the broader political dimension of logical empiricist philosophy. We focus on three practical projects of Rougier in the 1930s and 1940s: first, his attempts to integrate French-speaking philosophers into an international network of scientific philosophers by organizing two Unity of Science conferences in Paris; second, his role in the renewal of liberalism through the organization of the Walter Lippmann Colloquium; and third, his attempts at political (...) negotiations between Great Britain and the Vichy regime during the Second World War. These activities of Rougier in the 1930s and 1940s have so far never been discussed as part of a unified project on his part. Based on our investigations of these practical projects of Rougier, we argue that his relation to logical empiricist philosophers should primarily be understood on the level of action. His projects aimed to proliferate the concrete improvement of society and the lives of its citizens by expunging all metaphysical questions and speculations from the sphere of social discourse. Rougier conceived logical empiricist philosophers as allies to achieve such practical effects in society. (shrink)

L’emploi par Poincaré de la notion de convention au sujet des hypothèses géométriques signale un déplacement par rapport aux problématiques traditionnelles. La découverte des géométries non euclidiennes montre qu’il n’y a pas de cadre spatial unique ; plusieurs systèmes sont possibles. On affirme ainsi l’existence d’un aspect essentiel de la connaissance qui ne dérive pas des faits et ne relève ni de l’inné ni de l’intuition. L’introduction de la notion de convention, dont il s’agit de prendre la mesure, ouvre la (...) voie à une prise en compte des facteurs décisionnels en science. Nous nous proposons, dans cet article, d’analyser l’argumentation de Poincaré en reconstruisant sa position face aux doctrines de Kant et de Mill.By understanding geometrical hypotheses as conventions, Poincaré significantly alters the traditional philosophical discussion of space. The discovery of non-Euclidean geometries proves that there is not a single spatial framework ; several systems are possible. Thus, there is an essential feature of knowledge that derives neither from empirical facts nor from intuition or innate understanding. The introduction of the notion of convention, whose significance is at issue here, provides a way of understanding the element of free choice in science. This article aims at analyzing Poincaré’s reasoning, by contrasting his viewpoint with that of Kant and Mill. (shrink)