"Justice as Fairness: Political not Metaphysical" is an essay by John Rawls, published in 1985.[1] In it he describes his conception of justice. It comprises two main principles of liberty and equality; the second is subdivided into fair equality of opportunity and the difference principle.
Rawls arranges the principles in "lexical priority," prioritizing in the order of the liberty principle, fair equality of opportunity and the difference principle. This order determines the priorities of the principles if they conflict in practice. The principles are, however, intended as a single, comprehensive conception of justice—"Justice as Fairness"—and not to function individually. These principles are always applied so as to ensure that the "least advantaged" are benefitted and not hurt or forgotten.
Rawls originally presented the theory in his 1971 book A Theory of Justice, subsequently expanding upon several of its themes in his later book titled Political Liberalism.