Achieving justice and eliminating injustice should, it is widely thought, be our first political priority. Philosophers have constructed theories of justice, theories about the values which should regulate our collective decision making. For example, Liberal Egalitarians like Rawls regard liberty, equality, democracy and scientific knowledge as the political values, the values that govern a just society.

I shall argue that there can be no philosophical theory of justice because the values which constitute any plausible conception of justice will be mutually independent. What unites these elements and gives them priority over non-political values is not their internal logic but rather contingent socio-historical facts about which values our community can coalesce around. This is the fragmentation of justice.

For many of us there is a particular direction in which human history ought to be moving, one defined by our conception of justice. In the 1990s, it seemed as if the arc of history bent towards liberal democracy. Such optimism has since dissipated but we should query the philosophical as well as the historical premise behind it: does political morality really recommend a single direction of travel to all of humanity? The fragmentation of justice suggests otherwise and I shall sketch a non-progressive picture of human history.