400 B.C. Aristotle lays out the golden mean. This theory states that right courses of action always avoid extremes. Basically, moderation is the key to ethical behavior, according to Aristotle.More on Aristotle and the golden mean through The Window
20's A.D. Jesus Christ articulates "Do unto others as you would have them do unto you" maxim. This idea seems sensible and is accepted by most modern Americans, but is not without its share of disputable issues.
More on The Golden Rule, by Harry J. Gensler, S.J. of John Carroll University
1785 Immanuel Kant advances categorical imperative. As Kant put it, "Act on the maxim that you would want to become universal law." His theory emphasized acting upon principles that people would find universally acceptable.
More on categorical imperative, from the Internet Encyclopedia of Philosophy
1865 John Stuart Mill proposes utilitarianism. This idea parallels the democratic idea of majority rule, placing emphasis on "the greatest good for the greatest number." This method of discernment goes hand in hand with the concept of 'the people's right to know,' which mainly supports reporting on both positive and negative governmental activity.
More on utilitarianism, by Prof. C.D. Kay of Wofford University
1903 John Dewey advances pragmatism. He argued that the virtue of moral decisions had to be judged by their results. One problem with this system is that no one can be absolutely certain whether their actions will have positive or negative results, and for whom.
More on pragmatism, from the Internet Encyclopedia of Philosophy
1919 Hutchins Commission urges media to be socially responsible. This group studied mass media in the 1940's, concluding that journalists and other media persons should make decisions that responsibly serve society. The main problem here is that people's ideas of how society is most responsibly served differ very greatly.
More on Hutchins Commission, from University of Illinois at Urbana-Champaign
1971 John Rawls advances veil of ignorance. According to Rawls, choosing what is right requires blindness to social position and other discriminating factors. It requires that all people and situations be given an equal hearing and the same consideration.
More on the veil of ignorance, by Prof. C.D. Kay of Wofford University