In this chapter, I challenge the confidence that has been placed in hard and, in particular, soft paternalistic measures in the field of behavioural public policy. I consider the four limitations that have been proposed to human reasoning – i.e. limited imagination, willpower, objectivity and technical ability – but ultimately conclude that these are insufficient justification for paternalistic intervention, for two principal related reasons. First, it is impossible for a policy maker to discern what people desire in their own lives, and second, so long as they are not harming others, people should be free to pursue their own desires. The vision for the future of behavioural public policy that I propose here is thus consistent with classical liberal, and in particular, Millian thought: i.e. aim to educate people on the pros and cons of their actions and inactions so that they are better equipped to live the lives they wish to lead, but do not interfere directly in guiding them towards any particular end.