A contractarian approach to problems of ethics asks what solution could be agreed upon by contracting parties, starting from certain idealized positions (for example, no ignorance, no inequalities of power enabling one party to force unjust solutions upon another, no malicious ambitions). The idea of thinking of civil society, with its different distributions of rights and obligations, as if it were established by a social contract, derives from Hobbes and Rousseau . The utility of such a model was attacked by Hume, who asks why, given that no historical event of establishing a contract took place, it is useful to allocate rights and duties as if it had; he also points out that the actual distribution of these things in a society owes too much to contingent circumstances to be derivable from any such model. Similar positions in general ethical theory (sometimes called contractualism) see the right thing to do as one that could be agreed upon in a hypothetical contract. See also consent, Rawls.
Philosophy dictionary. Academic. 2011.