Abstract
I examine the foundations of a just society using the lens of decision theory. The conception of just society is from an individual’s viewpoint: where would I rather live if I have an equal chance of being any individual? Three alternative designs for a just society are examined. These are: laissez-faire, maximin and social minimum. Two assumptions about human nature clarify the distinction among three societies. The first assumption is that a representative individual’s utility function is concave. The second assumption recognizes that redistribution to achieve equality reduces total wealth. A rational individual would prefer a society where one is free to maximize one’s expected utility. A social minimum that includes both the provision of essential human needs and equality of opportunity (education, healthcare, access to capital) for a flourishing life emerges as a candidate solution for the basic structure of society.