 In seeking justification for the requirement of informed consent, we may therefore not have one task, but many. We need to justify this powerful, relatively non-controversial core, as well as a weaker and more questionable rim. It is possible that the core stems directly from natural right, whereas the rim is merely instrumental or conventional. It is also possible that they both rely on the same ground, say, the value of autonomy, but touch on it in different measures. Even if the core of the requirement of informed consent commands high priority, other parts may turn out to be easily overridable by competing values, including the value of advancing scientific research.