My aim is to present a conception of justice which generalizes and carries to a higher level of abstraction the familiar theory of the social contract as found,say,in locke,Rousseau and Kant,in order to do this we are not to think of the original contract as one to enter a particular society or to set up a particular from of goverment.Rather,the guiding idea is that the principles of justice for the basic structure of society are the object of the original agreement.They are the principles that free and rational persons concerned of further their own interests would accept in an imtial position of equality as defining the fundamental terms of their association .These principles are to regulate all further agreement,they specify the kinds of social cooperration that can be entered into and the forns of government that can be established.this way of regarding the principles of justice I shall call justice as fairness