 However, Mill’s perfectionist conception of happiness provides a more robust rationale against paternalism. For if a person’s happiness depends on her exercise of the capacities that make her a responsible agent, then a principal ingredient of her own good must include opportunities for responsible choice and self-determination. But then it becomes clear how autonomy is an important part of a person’s good and how paternalism undercuts her good in important and predictable ways. Mill may still not have an argument against successful paternalism, but his perfectionism gives him an argument that successful paternalism is much harder to achieve than one might have thought, because it is very hard to benefit an autonomous agent in ways that bypass her agency.