Why and How Contract could be possible: Consideration from the Perspective of Rawls and Buchanan

The classic contract explained why and how contract could be possible through a preoccupation with state of nature.Contrast to it,Rawls insists that state of nature couldnt guarantee a undistracted contract.Then,his hypothesis is preoccupied with original position,and admits some people to make any fundamental principle,in the case of this condition,the contract chosen by some relevant participant must be justice.James M.Buchanon,while,who immediately appeals to take account of people's strategy behavior and games by no means of any hypothesis.He claims that people's mutual benefited contract would be constructed so far as participants have made certain of property right and acknowledged their equal status of otherness.