Sometimes it seems as if we do what we think or know that we should not do. At least as often, it seems as if we do things when we think or know we could do something better. What is going on inside of us, when we perform such apparently akratic actions? How, if at all, are such actions expressive of our agency? Are some such actions actually akratic? Socrates is famously said to have denied that akratic actions were possible. Plato is famously supposed to have developed a theory of the soul to explain how they were after all possible, and Aristotle has a still different treatment of akratic actions, which makes use of his insights about practical knowledge and natural science. More recent theories have renewed the puzzle, but hardly solved it. In this lecture, we'll work our way through both the ancient and contemporary debates about how to characterize and understand akrasia, what's wrong with it, and how it can be cured.This Vorlesung complements both the Hauptseminar on Practical Truth and the Proseminar on Knowing How, Understanding, and Wisdom: all three bear directly on debates about phronesis, and so on Aristotelian Ethics. Students are therefore encouraged to attend either or both of those in conjunction with this Vorlesung, though neither participation in those courses nor interest in phronesis is required.