 The libertarian claim that valid informed consent is necessary and sufficient to justify exposing research participants to risks for the benefit of others seems to imply, consistent with the first principle of the Nuremberg Code, that research with individuals who cannot consent is unethical. This plausible and tempting claim commits one to the view that research with children, research in many emergency situations, and research with the demented elderly all are ethically impermissible. One could consistently maintain such a view but the social costs of adopting it would be great. It is estimated, for example, that approximately 70% of medications provided to children have not been tested in children, even for basic safety and efficacy (Roberts, Rodriquez, Murphy, Crescenzi 2003; Field &amp; Behrman 2004; Caldwell, Murphy, Butow, and Craig 2004). Absent clinical research with children, pediatricians will be forced to continue to provide frequently inappropriate treatment, leading to significant harms that could have been avoided by pursuing clinical research to identify better approaches.