The Phenomenology of Aristotle in Heidegger’s ‘Sein und Zeit: the Phenomenon of Aletheuein in the Concept of Eigentlichkeit

Tese arquivada ao abrigo da Portaria nº 227/2017 de 25 de Julho-Registo de Grau EstrangeiroIn the existential analysis of Dasein, Heidegger’s phenomenology is driven by the presence of Aristotle’s phenomenological nature of thought and its phenomenological possibilities. This study examines the early Heidegger’s retrieval of Aristotle’s a¹lhqeu¿ein in his inquiries at Marburg and the articulation of this notion in the concept of Eigentlichkeit in Sein und Zeit (1927). Turning to Aristotle’s analysis of faino/menon and lo/goj, Heidegger’s project in Marburg is motivated by the return to Aristotle in order to retrieve and exhibit a¹lhqeu¿ein as the phenomenon that articulates the research on factical Dasein in the world. In undertaking this kind of phenomenological reflection, Heidegger is not trying merely to clarify his own stance in relation to Aristotle, but he is also in fact reactivating the Greek (Aristotelian) sense of phenomenology retrieving Aristotle’s view on philosophical research. It is shown that the phenomenological description of Dasein to which Heidegger appeals in Being and Time is not a ‘project’ of his philosophy, but rather it arises as a possibility on the basis of the possibilities inherent in thinking (and so language) as such. In Sein und Zeit, the theme of Eigentlichkeit is situated from the beginning within Aristotle’s teleology and traced back to Aristotle’s understanding of life and pra½cij, since it is based upon the phenomenon of a¹lhqeu¿ein as the basic trait of human activity. It is argued that the point in revealing the practical foundation of Aristotle’s modes of a¹lhqeu¿ein is essentially to find out what it means for Dasein to be a form of ki/nhsij that opens up the possibility of authenticity in human being. In this pursuit, it becomes possible not only to regard authenticity as a form of a©lhqeu¿ein or articulative disclosing of being-in-the-world, but also as a temporal phenomenon whose origin is to be found in the Aristotelian ki¿nhsij and nouÍj underlying its core notion: Entschlossenheit. On the basis of this concept it is argued that authenticity cannot be determined nor exhausted by being-towards-death but, rather, by the most far-reaching possibility of a¹lhqeu¿ein: historicity