The knowledge base of empirical psychology is more expansive than ever before. So too is the impulse to integrate this factual knowledge into political theory. But how should this psychological turn be undertaken? What would a political psychology for political theorists look like? How could psychology credibly tackle the questions that political theorists characteristically ask, especially regarding the nature and consequences of prescriptive political judgment? In this thesis, I explore this issue through the framework of recent debates between political moralists—specifically, John Rawls, G. A. Cohen, and Peter Singer—and political realists—largely Bernard Williams. Deploying the insights of political realists, I argue that moralists cannot quarantine the relevance of psychological facts through the ideal of a 'pure' normative judgment. To explore what this empirical engagement might look like, I contrast these moralist ideals of judgment with Jonathan Haidt’s social intuitionism, which proposes a more affectively laden and pluralistic model of judgment. I then redeploy the insights of political realism to critique social intuitionism, to uncover its weaknesses from the perspective of existing political theory. Finally, to stabilize this critique, I lay out the framework for a reflexive political psychology, which acknowledges the co-constitutive relationship between the discipline of psychology and its subject matter: human psychology. This reflexive political psychology offers an agenda by which we can investigate the political usefulness of psychological and political theories.

Cette thèse vise à analyser, préciser et évaluer quel fut le rôle exact joué par Alexandre Koyré dans l'institutionnalisation de l'histoire des sciences aux Etats-Unis. Il s'agit de comprendre comment Koyré a renouvelé le paysage intellectuel dans lequel il s'insère au début des années 1940 et comment les historiens américains se sont approprié ses idées pour servir à la professionnalisation de l'enseignement de l'histoire des sciences aux États-Unis. / This dissertation aims at analyzing, specifying and estimating the exact role played by Alexandre Koyré in the institutionalization of the history of science in the United States. The goal is to understand how Koyré renewed the intellectual landscape in which he was inserted at the beginning of the 1940s, and how a number of American historians and philosophers did appropriate his ideas in their efforts to professionalize the history of science teaching in the United States.

L’objectif de cette thèse est de fournir un cadre théorique pour l’analyse philosophique des pratiques classificatoires en sciences. La classification, définie comme étant un geste épistémique dont l’objectif est de fournir une description du monde par découpage et discrimination, et par mise en relation des catégories ainsi formées, est un point de rencontre naturel entre philosophie et sciences. La tradition des espèces naturelles, considérée en philosophie des sciences comme la principale approche disponible pour l’analyse des pratiques classificatoires, est toutefois lacunaire. Dans le cadre de cette thèse, je démontre les faiblesses de cette approche et le besoin de mobiliser d’autres ressources épistémologiques pour penser la classification. À cet effet, je m’inspire de travaux en philosophie de la mesure s’inscrivant dans un courant de pensée que j’appelle le cohérentisme historique. Ces approches mettent l’accent sur les pratiques inférentielles et sur la charge théorique des observations en plus d’insister sur le dynamisme scientifique et la multitude de facteurs qui l’influencent (principe de respect, impératif de progrès, développements théoriques, nouveaux outils [mathématiques ou matériels], nouvelles données, histoire du champ disciplinaire, structure sociale de la recherche, etc.). Une fois ce cadre d’analyse épistémologique présenté en détail, je le mobilise pour étudier un ensemble de pratiques classificatoires en sciences, soit les pratiques phylogénétiques contemporaines. La phylogénétique est la discipline biologique qui vise à retracer les liens généalogiques qui unissent les êtres vivants. Les gènes et organismes sont ainsi regroupés au sein d’unités taxonomiques qui sont par la suite mises en relation. Ce champ disciplinaire a longtemps été associé de façon intime et exclusive au modèle arborescent, lui-même associé à la théorie de l’évolution par voie de sélection naturelle : les liens phylogénétiques entre organismes sont généralement représentés sous la forme d’un arbre, soit l’Arbre du vivant. Or, les dernières décennies ont vu émerger, au sein de la discipline, un compétiteur : le modèle réticulé. En analysant les différences et similarités qui lient ces deux types de modèles (modèles arborescents et modèles réseaux), je démontre que la transition d’un modèle à l’autre n’influence que superficiellement la pratique puisque la majorité de ses déterminants demeure inchangée. En bref, cette thèse présente un cadre d’analyse philosophique pour appréhender les pratiques classificatoires en sciences. J’importe des principes et des outils issus de travaux de la philosophie de la mesure afin de développer une philosophie de la classification qui comble les lacunes de la tradition des espèces naturelles. En s’ancrant dans ce que j’appelle le cohérentisme historique, cette thèse contribue non seulement à la bonne compréhension des pratiques classificatoires d’un point de vue épistémologique, mais aussi à la bonne compréhension des pratiques phylogénétiques contemporaines et de l’importante transition qui éloigne cette discipline de son modèle classique, soit l’Arbre du vivant. / The main objective of this dissertation is to offer a philosophical framework for the analysis of scientific classificatory practices. Classification, here defined as an epistemic action that describes the world by breaking down phenomena into categories and by establishing relevant relationships between these categories, is a natural bridge between philosophy and science. The tradition of natural kinds, which is currently the main approach in philosophy of science for analysing classificatory practices, has important shortcomings when it comes to epistemologically analyzing scientific classification. In this dissertation, I highlight these weaknesses and the consequent need to develop a novel framework for tackling classificatory practices. To achieve this, I draw on an existing trend in philosophy of measurement, which I coined historical coherentism. This approach is centered on the analysis of inferential practices and stresses the importance of the theoretical charge of observations. It also focuses on the dynamic nature of scientific fields and on the variety of factors that determine scientific progress (principle of respect, imperative of progress, theoretical developments, mathematical and material innovations, new data, the history of a field of research, the social structure of the scientific community, etc.). After the detailed presentation and exploration of this epistemological framework, I use it to tackle a set of scientific classificatory practices, namely contemporary phylogenetic practices. Phylogenetics is the biological discipline that aims to reconstruct the genealogical relationships uniting living beings. Genes and organisms are grouped into operative taxonomic units, and these units are then connected within a system. Since its inception, phylogenetics has been intimately tied to tree-based models, with these tree-based models themselves tied to the theory of evolution by means of natural selection: the phylogenetic system connecting all living organisms takes the form of a tree, the Tree of Life. In the last few decades, however, an alternative type of models has gained more attention and support within the field: network-based models. Using historical coherentism, I analyze the differences and similarities between the two competing types of models (tree-based models and network-based models) and show that the transition from one to the other only superficially changes phylogenetic practices. Indeed, many factors that constrain these practices remain unchanged whether researchers use tree-based or network-based models. In short, this thesis presents a philosophical framework for the analysis of classificatory practices in sciences. I use various principles and tools imported from the philosophy of measurement to develop a philosophy of classification that covers the weaknesses of the tradition of natural kinds. By anchoring my work in historical coherentism, I contribute not only to our understanding of classificatory practices, from an epistemological perspective, but also to a better understanding of contemporary phylogenetic practices and of the significant transition that leads this discipline away from its classical model, the Tree of Life.

A critical investigation of the public/private distinction as it has been conceived in Anglo-American political thinking in the second half of the 20th century. A broadly held consensus has developed amongst many theorists that public/private does not refer to any single determinate distinction or relationship but rather to an often ambiguous range of related but analytically distinct conceptual oppositions. The argument of this thesis is that if we approach public/private in the search for analytic or conceptual clarity then this consensus is correct. Against this I propose that a number of the most dominant invocations of the distinction can be understood to express public/private as an irreducibly political dialectic that mediates the relationship between the subjective and objective side of social and political life. By locating these conceptually diverse invocations within a broader and more determinate framework of the historical development and contestation of the boundaries which establish the conditions for subjectivity, as the assertion of political agency, on the one hand, and which demarcate, police and defend these particular boundaries, as part of the objectively given character of social life and institutional organisation, on the other hand, then a more determinate character to public/private can be recognized. I then seek to explore the capacity of this model to capture and explain the peculiar post-war problematisation of public/private amongst a number of new left thinkers in Britain and America.