 If the myriad restrictions on clinical research were justified on the basis of hard paternalism they would represent restrictions on individuals’ autonomous actions. However, the data on the extent to which otherwise competent adults fail to understand what they need to understand to provide valid consent suggests that the limitations can instead be justified on the grounds of soft paternalism. This suggests that while the restrictions may limit the liberty of adult research participants, they do not limit their autonomy. In this way, one may regard many of the regulations on clinical research not as inconsistent with the libertarian ideal, but instead as starting from that ideal and recognizing that otherwise competent adults often fail to attain it.