This work is based on the degree thesis, entitled «The concept of Tragedy and its functioning in the aesthetic theories of Aristotle, Schelling and Nietzsche» (Η έννοια της Τραγωδίας και ο ρόλος της στην αισθητική, στον Αριστοτέλη, στον Schelling και στον Nietzsche) by Anastasia Gasia, delivered at the Department of Philosophy, University of Patras (2008). The purpose of the degree thesis was to explore the track and the role that the Greek tragedy curved, inside the philosophical thought, through the presentation, the analysis and the comparison of the aesthetic approaches of the above thinkers. The aesthetic theories were presented with reference to their historical frame, on one hand, in order to lighten the intellectual background on which the thought of these philosophers emerged and, on the other, in order to understand their role in the path of aesthetics. The particular interpretations on ancient Greek tragedy were selected due to the decisive role they played in the philosophical proceedings, with regard to the way of thinking on the essence and the value of art and of human existence, too.