[A]nyone who applies to another a standard of which he would complain if it were applied to himself has no moral grounds for his complaint. He is being both immoral and illogical. It follows, then, that the Golden Rule formulates a fundamental requirement of justice, that everyone's conduct must be judged by the same standards, and that no one has, in general, any warranted claim to a special or privileged position. It is therefore at the basis of the Principle of Justice, that what is right or wrong for one person must be right or wrong for any similar person in similar circumstances. Stated differently but equivalently: What is right for one person cannot be wrong for another, unless there is some relevant difference in their natures or circumstances.
(Marcus G. Singer, "The Golden Rule," Philosophy 38 [October 1963]: 293-314, at 302)
