Socratic philosophy and Christian religion encourage the belief that justice is timeless. In fact few ideas are more ephemeral.
John Rawls’s theory of justice has dominated Anglo-American philosophy for a generation. It seeks to develop an account of justice that works only with widely accepted moral intuitions of fairness and relies at no point on controversial positions in ethics. The fruit of this modesty is a pious commentary on conventional moral beliefs.
Followers of Rawls avoid inspecting their moral intuitions too closely. Perhaps this is just as well. If they scrutinised them, they would find they had a history – often a rather short history. Today everyone knows that inequality is wrong. A century ago everyone knew that gay sex was wrong. The intuitions people have on moral questions are intensely felt. They are also shallow and transient to the last degree.
The egalitarian beliefs on which Rawls’s theory is founded are like the sexual mores that were once believed to be the core of morality. The most local and changeable of things, they are revered as the very essence of morality. As conventional opinion moves on, the current egalitarian consensus will be followed by a new orthodoxy, equally certain that it embodies unchanging moral truth.
Justice is an artefact of custom. Where customs are unsettled its dictates soon become dated. Ideas of justice are as timeless as fashions in hats.