This dissertation shows how Martin Heidegger and Michel Foucault, by questioning the very understanding of the subject-object relationship on which all epistemology is grounded, challenge two of its most cherished beliefs: 1. Thought and knowledge are essentially activities on the part of the subject understood anthropologically or transcendentally. 2. The history of knowledge exhibits teleological progress towards a better and more comprehensive account of its objects. In contrast to traditional epistemology, both Heidegger and Foucault show how thought and knowledge are (...) not just acts, which can be attributed to the subject but also events which elude any such subjective characterization. They also show us how the history of knowledge exhibits ruptures when the very character of knowledge undergoes drastic transformation in the course of history. The dissertation concludes by hinting at how these new accounts of thought and knowledge have the potential to shake the very foundations of epistemology and lead us to a new framework for discussing the most basic questions of epistemology, towards an epistemology of ruptures. (shrink)