Cass Sunstein and Richard Thaler have been arguing for what they named libertarian paternalism (henceforth LP). Their proposal generated extensive debate as to how and whether LP might lead down a full-blown paternalistic slippery slope. LP has the indubitable merit of having connected the best of the empirical psychological and sociological evidence to public and private policy making. It is unclear, though, to what extent the implementation of policies so constructed could enhance the capability for the exercise of an autonomous citizenship. Sunstein and Thaler submit it that in most of the cases in which one is confronted with a set of choices, some default option must be picked out. In those cases whoever devises the features of the set of options ought to rank them according to the moral principle of non-maleficence and possibly to that of beneficence. In this paper we argue that LP can be better implemented if there is a preliminary deliberative debate among the stakeholders that elicits their preferences, and makes it possible to rationally defend them.