Although to this day some doubt remains about whether we can find, in Greek philosophy, a concept that corresponds to the latin notion of the will, nobody seems to question the fact that the greek philosophers were the first to try to understand the phenomenon which today we call weakness of the will – and that they called akrasia. Although the first philosopher employed this term when discussing the problem was Aristotle (EN VII.1), the first philosophical discussion about akrasia is to be found in Plato’s Protagoras. In this dialogue, the phenomenon that is discussed is called being defeated by pleasures. As we know, Socrates denies that such a thing is even possible and affirms his famous paradox according to which nobody errs willingly. This works main goal is to compare the problem of akrasia in Plato and Aristotle, so that we can better understand something which is still a matter of great dissent: how much of the Socratic explanation of the phenomenon is accepted by Aristotle and how much of it is discarded? In order to answer this question, Ive tried to highlight the differences that separate the authors in what concerns both their description of akrasia and the way they conceive the voluntary act. Ive also dedicated the introduction of the work to a discussion about two plays of Euripides, Hyppolitus and Medea, with the objective of shedding some light in what we might perhaps call the pre-philosophical roots of the problem.