Persons of diminished capacity, especially those who are still legally competent but are de facto incompetent should still be able to participate in moderately risky research projects that benefit the class of persons with similar diseases. It is argued that this view can be supported with a modified communitarianism, a philosophy ofmedicine that holds that health care is a joint responsibility that meets foundational human needs. The mechanism for obtaining a substituted consent I call ``community consent,'' and distinguish this from (...) the usual family or surrogate consent for treatment. Care givers are included in the community that might consent for an individual who has no identifiable family members. (shrink)