The first principle, autonomy, entails that health care professionals should respect the autonomous decisions of competent adults. The second principle, beneficence, holds that they should aim to do good—i.e., to promote the interests of their patients. The third principle, nonmaleficence, requires that they should do no harm. Finally, the fourth principle, justice, holds that they should act fairly when the interests of different individuals or groups are in competition—e.g., by promoting the fair allocation of health care resources.