AbstractThe “welcome return” to “substantive political philosophy” that Rawls's A Theory of Justice was said to herald has resulted in forty years of proposals seeking to show that philosophical reflection leads to the demonstrable truth of almost every and any conceivable view of the justice of property rights. Select any view—from the justice of unregulated capitalist markets to the most extreme forms of egalitarianism—and one will find that some philosophers have proclaimed that rational reflection uniquely leads to its justice. This is, I believe, a sort of ideological thinking masquerading as philosophizing. In this paper, using some tools from game theory as well as experimental findings, I seek to sketch a non-ideological approach to the question of the justification of property rights. On this approach the aim of political philosophy is, first and foremost, to reflect on whether our social rules of property are within the “optimal eligible set” of rules acceptable to all.