From an objective point of view, Book IX of the Laws is concerned with the foundation of moral responsibility, a central issue in Plato s theory of punishment, which couples the socratic thesis that no one commits evil willingly, with the practical necessity for a gradation of penalties, which is derived from the traditional distinction between voluntary and involuntary crimes. Distinguishing two independent aspects of wrongdoing – damage and injustice – Plato argues that the former requires only atonement, whereas punishment is conceived as a measure to improve the soul, affected by disordered emotions or ignorance, causes of injustice. This question also presents a subjective aspect: from the agent’s point of view, in his relation with himself and disregarding the social advantages of justice, is there any reason to be fair? For Plato, injustice tears the soul’s harmony, preventing the internal dialogue of a person with himself and affecting his capacity to think. In his later dialogues, as Plato’s conceptions about the sources of evil evolve, it remains clear that punishment for injustice does not depend on the soul’s survival after death, but springs from a universal law according to which like clings to like, a principle which determines that evil induces the wicked to live with evil, disrupting his inner life.