Nesta pesquisa, busca-se analisar alguns aspectos da vinculação entre dois momentos da obra de Jean-Paul Sartre a partir da relação entre ontologia e história. O primeiro momento, marcado pela ontologia fenomenológica de O ser e o nada, apresentaria estruturas caracterizadas por uma a-historicidade; o segundo momento, marcado principalmente pela aproximação do marxismo e um grande peso dado à história, encontra-se principalmente em Questão de método e Crítica da razão dialética. Ao contrário das interpretações que afirmam a incompatibilidade entre esses dois momentos da obra de Sartre, mostra-se ao longo do texto que as estruturas da ontologia fenomenológica, se não apresentam uma formulação sobre a história, são uma abertura para ela, pois descrevem um processo de totalização de si do sujeito que o lança em uma totalização de totalizações a qual, por sua vez, é o próprio processo histórico. / This research aims to analyze some aspects of the link between two moments of Jean-Paul Sartre\'s philosophy regarding the relation between ontology and history. The first moment, marked by the phenomenological ontology of Being and Nothingness, would present structures characterized by a-historicity; the second moment, marked by an approach of Marxism and by a great weight being ascribed to history, is found mainly in Question of method and in Critique of dialectical reason. Contrary to the interpretations that sustain the existence of an incompatibility between these two moments of Sartre\'s thought, this work argues that the structures of phenomenological ontology, if they do not present a formulation about history, they nonetheless hold an opening towards it, since they describe a process through which the subject carries out a totalization of herself that throws her into a totalization of totalizations which, in turn, is the historical process itself.

Nesta pesquisa, busca-se analisar alguns aspectos da vinculação entre dois momentos da obra de Jean-Paul Sartre a partir da relação entre ontologia e história. O primeiro momento, marcado pela ontologia fenomenológica de O ser e o nada, apresentaria estruturas caracterizadas por uma a-historicidade; o segundo momento, marcado principalmente pela aproximação do marxismo e um grande peso dado à história, encontra-se principalmente em Questão de método e Crítica da razão dialética. Ao contrário das interpretações que afirmam a incompatibilidade entre esses dois momentos da obra de Sartre, mostra-se ao longo do texto que as estruturas da ontologia fenomenológica, se não apresentam uma formulação sobre a história, são uma abertura para ela, pois descrevem um processo de totalização de si do sujeito que o lança em uma totalização de totalizações a qual, por sua vez, é o próprio processo histórico. / This research aims to analyze some aspects of the link between two moments of Jean-Paul Sartre\'s philosophy regarding the relation between ontology and history. The first moment, marked by the phenomenological ontology of Being and Nothingness, would present structures characterized by a-historicity; the second moment, marked by an approach of Marxism and by a great weight being ascribed to history, is found mainly in Question of method and in Critique of dialectical reason. Contrary to the interpretations that sustain the existence of an incompatibility between these two moments of Sartre\'s thought, this work argues that the structures of phenomenological ontology, if they do not present a formulation about history, they nonetheless hold an opening towards it, since they describe a process through which the subject carries out a totalization of herself that throws her into a totalization of totalizations which, in turn, is the historical process itself.

Cette thèse d'algèbre commutative porte principalement sur la théorie de la profondeur. Nous nous efforçons d'en fournir une approche épurée d'hypothèse noethérienne dans l'espoir d'échapper aux idéaux premiers et ceci afin de manier des objets élémentaires et explicites. Parmi ces objets, figurent les complexes algébriques de Koszul et de Cech dont nous étudions les propriétés cohomologiques grâce à des résultats simples portant sur la cohomologie du totalisé d'un bicomplexe. Dans le cadre de la cohomologie de Cech, nous avons établi la longue suite exacte de Mayer-Vietoris avec un traitement reposant uniquement sur le maniement des éléments. Une autre notion importante est celle de dimension de Krull. Sa caractérisation en termes de monoïdes bords permet de montrer de manière expéditive le théorème d'annulation de Grothendieck en cohomologie de Cech. Nous fournissons également un algorithme permettant de compléter un polynôme homogène en un h.s.o.p.. La profondeur est intimement liée à la théorie des résolutions libres/projectives finies, en témoigne le théorème de Ferrand-Vasconcelos dont nous rapportons une généralisation due à Jouanolou. Par ailleurs, nous revenons sur des résultats faisant intervenir la profondeur des idéaux caractéristiques d'une résolution libre finie. Nous revisitons, dans un cas particulier, une construction due à Tate permettant d'expliciter une résolution projective totalement effective de l'idéal d'un point lisse d'une hypersurface. Enfin, nous abordons la théorie de la régularité en dimension 1 via l'étude des idéaux inversibles et fournissons un algorithme implémenté en Magma calculant l'anneau des entiers d'un corps de nombres. / This Commutative Algebra thesis focuses mainly on the depth theory. We try to provide an approach without noetherian hypothesis in order to escape prime ideals and to handle only basic and explicit concepts. We study the algebraic complexes of Koszul and Cech and their cohomological properties by using simple results on the cohomology of the totalization of a bicomplex. In the Cech cohomology context we established the long exact sequence of Mayer-Vietoris only with a treatment based on the elements. Another important concept is that of Krull dimension. Its characterization in terms of monoids allows us to show expeditiously the vanishing Grothendieck theorem in Cech cohomology.We also provide an algorithm to complete a omogeneous polynomial in a h.s.o.p.. The depth is closely related to the theory of finite free/projective resolutions. We report a generalization of the Ferrand-Vasconcelos theorem due to Jouanolou. In addition, we review some results involving the depth of the ideals of expected ranks in a finite free resolution.We revisit, in a particular case, a construction due to Tate. This allows us to give an effective projective resolution of the ideal of a point of a smooth hypersurface. Finally, we discuss the regularity theory in dimension 1 by studying invertible ideals and provide an algorithm implemented in Magma computing the ring of integers of a number field.