Nous partons du constat que l’actuelle urgence écologique (réchauffement climatique, crise de la biodiversité, pollutions) constitue notre condition historique durable. Causée par des activités économiques et sociales identifiables, elle engage la pérennité de multiples espèces vivantes et met en question l’avenir de notre espèce. Cette thèse de philosophie interroge le concept d’espèce humaine, saisi sous l’angle de la naturalité évolutive et écologique, pour prendre acte de la fin de sa version pré-darwinienne sans rouvrir la route au biologisme racialiste et aux délires hiérarchiques criminels que ce dernier a accompagnés. L’enjeu théorique est d’élaborer une ontologie de l’espèce humaine, qui ne cède pas aux mystifications naturalisantes, mais fournisse des repères pour affronter l’urgence écologique. Cette ontologie se forge avec Hans Jonas et Robert Antelme, deux auteurs marqués par l’expérience du nazisme, qui aident à formuler un monisme dialectique non réductionniste, dont puisse dériver une éthique de la vie dans le monde, de la reconnaissance et de la solidarité élargies. La conviction qui guide ce travail est que l’urgence écologique est politique en ce que s’y joue la projection de destins collectifs. Contre la tentation de sauver l’espèce humaine (ou certaines de ses portions) via des « augmentations » biotechnologiques prétendant la faire passer au-delà de la catastrophe ou au-delà d’elle-même, tout en esquivant notre responsabilité présente, nous soutenons que la considération des « limites planétaires », où se diffractent spectre de la mort et désir de pouvoir, appelle un travail sur les conditions d’habitabilité humaine et non-humaine de ce monde, dans lequel l’expérience démocratique trouve matière à se renouveler sans céder à la panique. / The starting point of my study is the observation that the current ecological emergency (global warming, biodiversity crisis, pollution) shapes our long-term historical condition. The ecological emergency, which results from identifiable economic and social activities, threatens the continued sustainability of a wide range of species and places the future of our species in jeopardy. My dissertation in philosophy consequently explores the concept of human species, which I address from the point of view of its evolving and ecological naturality. In so doing, I intend to take note of the end of a pre-Darwinian definition, and at the same time I refuse to pave the way for any racialist biologism and for the criminal hierarchies it brought about. What is at stake here for theoretical research is the elaboration of an ontology of human species, which will not give in to any deceptive naturalizing doctrine and will provide us with landmarks to face the ecological emergency. This ontology builds upon two authors, Hans Jonas and Robert Antelme, who endured the experience of Nazism. Their works are central to elaborate a non-reductionist dialectical monism, which can generate an ethics of our life in the world and an ethics of greater recognition and extended solidarity. I argue that the ecological emergency is political in so far as it is the future of collective destinies which is at stake. My approach dismisses the urge to save the human species – or parts of it - by resorting to biotechnological enhancements which would supposedly help our species to step beyond the catastrophe or even beyond “humanity” while shirking our responsibility here and now. I accordingly claim that deeper consideration of planetary boundaries - as well as the spectre of death and the desire for power they imply - calls for a work on the conditions in which humans and non-humans can properly inhabit the world and the democratic experience can be renewed without giving way to panic.

The dissertation argues that the development of the British abolition movement was based on the abolitionists' perception that their actions were kairotic; they attempted to shape their own kairos by taking temporal events and reinterpreting them to construct a kairotic process that led to a perceived fulfillment: abolition. Thus, the dissertation examines the rhetorical strategies used by white abolitionists to construct an abolitionist kairos that was designed to produce salvation for white Britons more than it was to help free blacks. The dissertation especially examines the three major texts produced by black persons living in England during the late eighteenth centuryIgnatius Sancho's Letters of the Late Ignatius Sancho (1782), Ottobauh Cugoano's Thoughts and Sentiments on the Evil of Slavery (1787), and Olaudah Equiano's The Interesting Narrative of the Life of Olaudah Equiano, or Gustavus Vassa, the African (1789)to illustrate how black rhetoric was appropriated by whites to fulfill their own kairotic desires. By examining the rhetorical strategies employed in both white and black rhetorics, the dissertation illustrates how the abolitionists thought the movement was shaped by, and how they were shaping the movement through, kairotic time. While the dissertation contends that the abolition movement was rhetorically designed to provide redemption, and thus salvation, it illustrates that the abolitionist's intent was not merely to save the slave, but to redeem blacks first in the eyes of white Christians by opening blacks to an understanding and acceptance of God. Perhaps more importantly, abolitionists would use black salvation to buy back their own souls and the soul of their nation in the eyes of God in order to regain their own salvation lost in the slave trade. But ironically, they had to appear to be saving others to save themselves. So white abolitionists used the black narratives to persuade their overwhelmingly white audience that slavery was as bad for them as it was for the African slave. And in the process, a corpus of black writing was produced that gives current readers two glimpses of one world.