Clinical research with adults who are unable to provide informed consent has the potential to improve understanding and care of a number of devastating conditions. This research also has the potential to exploit some of society's most vulnerable members. Recently, a number of task forces and individual writers have proposed guidelines to ensure that such research is both possible and ethical. Yet, there is widespread disagreement over which safeguards should be adopted. In the present paper, I consider to what extent these disagreements can be resolved by appeal to a general account of the interests of subjects who are unable to consent and the conditions that must be satisfied for research enrollment to constitute exploitation of their inability to make their own decisions.