Until recently, the ethical nature of public health has been implicitly assumed rather than explicitly stated. Increasingly, however, society is demanding explicit attention to ethics. This demand arises from: technological advances that create new possibilities, and with them, new ethical dilemmas; new challenges to health such as the advent of human immunodeficiency virus; abuses of power, such as the Tuskegee study of syphilis; and an increasingly pluralistic society in which we can no longer simply adopt the values from a single culture or religion, but we must work out our common values in the midst of diversity. What does it mean to "work out our common values in the midst of diversity" across cultures and religions? How can we go about this? What are the public health implications of different cultural and religious values and ethics?