[pt] O objetivo da dissertação é analisar criticamente o uso do conceito do Antropoceno pela linha crítica de teoria das Relações Internacionais. Isso se faz com um foco específico na origem do conceito em Ciência do Sistema Terrestre (CST), e através de uma discussão geral sobre autoridade científica atribuída à ciência moderna e suas conexões com práticas de world-making, entendidas especificamente como cosmologias científicas, e em relação com mobilização de propostas na política internacional. Nesse sentido, a discussão explora a construção de CST e propõe a formulação do Antropoceno como relacionada com os comprometimentos políticos dessa disciplina – a partir daí, sugere-se o uso da problematização Foucaultiana como forma de análise das soluções políticas ao Antropoceno propostas pela disciplina. A seguir, a dissertação conecta as Ciências do Sistema Terrestre com outros momentos de desenvolvimento da ciência moderna com o âmbito de mover uma discussão geral sobre o poder de uma autoridade científica legitimar formas de política internacional através de práticas de world-making. Com isso, a discussão expande em dois mundos e formulações de política internacional possíveis advindos de distintas interpretações do Antropoceno. Finalmente, no que se refere à literatura de Relações Internacionais, a dissertação avalia como a apropriação do conceito de Antropoceno a partir de CST é realizada, prestando atenção especificamente na chamada por uma mudança na ontologia da disciplina e na relação entendida como desejável entre teoria e prática política presente na literatura, ambos elementos associados à CST. Por último, a noção de problematização é retomada para se analisar as soluções políticas e intelectuais propostas pela literatura Crítica de Relações Internacionais em sua mobilização do Antropoceno. / [en] This dissertation attempts to critically analyze the mobilization of the concept of the Anthropocene by Critical International Relations literature. It does so with a particular focus on the origins of the concept within Earth System Sciences (ESS), and within a more general discussion over the scientific authority of modern science and its connections to practices of world-making - discussed specifically in terms of scientific cosmologies - and propositions over international politics. As such, the discussion explores the construction of ESS and the formulation of the Anthropocene as related to the political commitments of the discipline and proposes the use of the Foucauldian problematization to analyze the political solutions stemming from the discipline. Then, the dissertation connects Earth System Sciences to other scientific endeavors, in a different historical context in order to move a more generalized discussion on the power of scientific authority to inform international politics through world-making practices. With that, the discussion lays out two possible worlds and political implications stemming from interpretations of the Anthropocene. Finally, within IR literature the dissertation assesses how the appropriation of the Anthropocene is conducted, paying particular attention to the call for an ontological shift within the discipline and to the specific relationship between theory and political action present in the literature, both elements connected to ESS. At last, the notion of problematization is brought back in order to analyze the intellectual and political solutions brought forth by Critical IR in their mobilization of the Anthropocene.

Cette thèse est une enquête d'histoire et de philosophie des sciences sur l'hypothèse Gaïa (HG) proposée par Lovelock et Margulis dans les années 1970. L'examen historique de l'élaboration d'HG et de sa très riche réception dans diverses disciplines scientifiques (climatologie, biogéochimie, géochimie, biologie de l'évolution, écologie et sciences de la complexité) et au sein des mouvements environnementalistes nous conduit à montrer qu'une ambiguïté majeure sur le statut d'HG grève la littérature : qu'est-ce qu'HG ? Nous montrons qu'HG a été considérée tantôt comme une hypothèse, tantôt comme une théorie, tantôt comme un programme de recherche, tantôt comme une philosophie de la nature. Chacune de ces lectures est ensuite examinée. Nous proposons une caractérisation épistémologique et historique d'HG montrant qu'HG ne doit pas être interprétée comme une hypothèse devant être confrontée de manière directe aux faits, mais comme une théorie élaborée avec des modèles. Nous clarifions alors le rôle et le statut méthodologique des modèles et théories d'HG ainsi que les concepts et hypothèses fondamentales qui les sous-tendent. La reconnaissance de Gaïa comme un système constitué des vivants et de l'environnement avec lequel ils interagissent a été l'origine de la constitution d'un nouveau programme de recherche: les sciences du système Terre. Nous proposons une histoire et une caractérisation de ce programme, repérons les déplacements philosophiques qu'il a opérés à propos des concepts de vie, d'environnement et de nature puis analysons les liens entre les conceptions que Lovelock a de Gaïa et les prescriptions environnementales qu'il a prononcées au nom de Gaïa. / The Gaia hypothesis (GH) proposed in the 1970's by Lovelock and Margulis is here analyzed from a history and philosophy of science perspective. The historical analysis of GH's elaboration and rich reception across various disciplines (climatology, biogeochemistry, geochemistry, evolutionary biology, ecology and complexity sciences) and within environmentalist movements leads me to argue that a major ambiguity plagues the relevant literatures: what is GH? I show that GH has been considered as a hypothesis, as a theory, as a research program, or as a philosophy of nature. Each of these interpretations is then analyzed. An epistemological and historical characterisation of GH shows that GH should not be interpreted as a hypothesis which ought to be confronted directly to empirical facts, but as a theory elaborated with models. I elucidate the methodological role and status of GH's models and theories before clarifying the concepts and expliciting the fundamental hypotheses underlying these models and theories. The recognition of Gaia as a system constituted of living organisms and the environment with which they internet led to the constitution of a new research program: the Earth system sciences. I offer a history and a characterisation of this research program, specify the philosophical shifts it brought about concepts such as life, the environment and nature and I analyze the relationships between Lovelock's conceptions of Gaia and the environmental prescriptions he pronounced in the name of Gaia.