This dissertation examines the relations between philosophy and etymology in its broadest sense through an analysis of the different words for truth that, during the early history of philosophy, have given way to the singular concept of truth dominating philosophy: alētheia. By inspecting the fate of the related adjectives eteos, etumos, etētumos, the Democritean concept of eteē, the beginnings of etymology, the Socratic method of exetasis, and the repression and relatively recent reemergence of these a case is made for a more complex genealogy of philosophical truth, tightly related to the life of the philosopher and their capacity to speak truth. Through five examples, each representing a different strand of the etymological etymon, this dissertation reviews the rise of alētheia as philosophically dominant conception of truth in Ancient Greek epic and tragic literature and Socratic dialogues; the Democritean concept of eteē, its repression by Plato, and its rediscovery in the early work of Friedrich Nietzsche; the development etymology as a part of grammatical investigation, starting with Plato's Cratylus and its ancient reception; the Socratic method of exetasis and its brief afterlife in the theory of rhetorics; and finally the late lectures at the Collège de France of Michel Foucault, which offer a striking synthesis of the different themes lined out previously through his recapitulation of etumos logos and philosophy as a practice of parrhēsia. In conclusion, a short survey is given of the different post-Nietzschean approaches to the relation between philosophy and etymology – either through the development of etymological irreducibility in the work of Martin Heidegger and Jacques Derrida, or through the complete evacuation of truth from philosophy by Alain Badiou. A final, preliminary proposal is made to open up the research presented in form of an etics.