John Rawls and the Difference Principle

John Rawls (1921–2002) was born and brought up in Baltimore, Maryland. His father was a lawyer and his mother a chapter president of the League of Women Voters. He entered Princeton University at the outbreak of the Second World War and, on completing his degree, joined the US army and served in New Guinea and the Philippines. He was in the Pacific when the US dropped its atomic bomb on Hiroshima in August 1945, an act which he later described as a “grave wrong against (the) civilian population” (1999). He said that since his late teens he had been concerned about moral questions and the religious and philosophical basis on which they might be answered, and that the three years he spent in the US Army in World War II led him to be also concerned about political questions. After the war he returned to Princeton, spent a year in Oxford and moved to Cornell, MIT and, in 1962, to Harvard, where he taught for thirty years. His students included the philosophers, Onora O’Neill and Christine Korsgaard.

His first papers in political philosophy appeared in the 1950s and “A Theory of Justice” in 1971. This book is generally regarded as the greatest contribution to political philosophy in the 20th century, and led to a renewed surge of interest in the subject. After 1971 he continued to expand on and modify his views. His most significant later work is “Political Liberalism” (1993).

In “A Theory of Justice” (1971) he advances three principles: the principle of justice (everyone has a right to a fully adequate scheme of basic rights and liberties), the fair opportunity principle (everyone is entitled to fair equality of opportunity with respect to offices and positions) and the difference principle (inequalities are justified only if they are to be to the greatest benefit of the least advantaged members of society). Despite the egalitarian nature of his “Theory of Justice” Rawls recognized that if especially creative individuals are paid better then this could benefit society in the following way: such inequalities can be tolerated, but not if everyone else benefits (a commonly held view) but only if the worst off benefit as much as possible. This is the crucial point of the difference principle, which was Rawls’s single most important original idea.

In order to arrive at these principles Rawls devised an intriguing thought experiment, a hypothetical social contract, which is reached by putting people into an “original position”. The idea here is that if people are asked to consider how society should best be run, what the principles of justice should be, then they will try to set things up to their own advantage. So, for instance, a rich person will opt for low taxes for the rich, but a poor person would want higher taxes for the rich. However if these two people are behind a “veil of ignorance” and don’t know how much money they each have, they will choose a more generally fair tax system. Behind the veil of ignorance people are unaware of anything that might bias their views on the kinds of principles of justice they would prefer. They continue to act in their own self-interest, but do not know anything about their gender, ethnicity, economic resources, social class, individual tastes and interests, and conception of the good. So it is their ignorance of these sources of bias which makes them impartial (Wolff, 2012: 241).

In his later book, Political Liberalism (1993) Rawls drew a distinction between liberalism as a philosophy of life and liberalism as a set of less wide-ranging political principles. Many liberals have seen liberalism as a means to making possible a certain way of life, but in the kind of liberal society which Rawls envisaged he did not set out a notion of what the good life should be, but appealed instead to more general principles of fairness, reciprocity and mutual respect. Rawls, who was strongly influenced by the Kantian notions of reason and autonomy or self-determination, thought that rational citizens should be free to choose their own “conception of the good”, but could agree on these general principles regardless of their views on religion, morality and human nature, and so come to what he called an “overlapping consensus”. What ensured the stability of a modern pluralistic society structured as Rawls has suggested is the fact that the principles of justice reflect the shared understanding of citizens as rational, free and equal.

Rawls has been criticized by Michael Sandel (1998) who has argued that we all have deeply embedded social ties of loyalty which we have not chosen, but which inevitably arise from the social circumstances in which we have grown up, and that Rawls does not take this sufficiently into consideration in his theory of justice. Sandel argues further that a just society should be based to a lesser extent on individual freedom and be orientated more towards the common good.

In his last book, The Law of Peoples (1999) Rawls tried to apply some of his ideas to the sphere of international relations between liberal and non-liberal states. He describes the two main ideas which motivate this book and which, he thinks, might help to create a “realistic utopia”:

  • One is that the great evils of human history—unjust war and oppression, religious persecution and the denial of liberty of conscience, starvation and poverty, not to mention genocide and mass murder—follow from political injustice, with its own cruelties and callousness …
  • The other main idea, obviously connected with the first, is that, once the gravest forms of political injustice are eliminated by following just (or at least decent) social policies and establishing just (or at least decent) basic institutions, these great evils will eventually disappear. (1999: 6–7)

Rawls’ theory of justice, and especially his difference principle, have influenced both political philosophy and political practice, especially in some European countries, where a generation of politicians who have read Rawls has come to power and has implemented policies specifically designed to help the poorest in society.

Paul Crichton
London, 21 June 2013


Rawls, J., 1971, A Theory of Justice, Cambridge: Harvard University Press.  
Rawls, J. 1993, Political Liberalism, New York: Columbia University Press.

Rawls, J. (1999) The Law of Peoples, Cambridge: Harvard University Press.

Sandel, M.  (1998) Liberalism and the Limits of Justice, Cambridge: Cambridge University Press. 

Wolff, J. (2012) Jonathan Wolff on John Rawls on Justice in: Philosophy Bites Back, Oxford: Oxford University Press.