Naturalistic       Metaphysical                Metaphysical
      |               nonteleological             teleological
      |                    |                             |
   Hobbes                |                             |
      |                 Locke                      Bentham
   Hume                  |                             |
     ||                 Rousseau                       |
     ||                    |                          Mill
     ||                  Kant                          |
     ||                    |                             |
     ||                  Rawls      +-----------------+  |
     ||                    | |      |                 |  |
     ||                    | +------+               Harsanyi
     ||                    V                          V  V
     ||              +-----------------------+      +------------------------+
     |+------------> |egalitarianism         |      |utilitarianism          |
     |               +-----------------------+      +------------------------+
     +--------------------------------------------------------^






              This shows how various thinkers arrived
              at  one or the other of the rival social
              contract theories.

Source : Game Theory and the Social Contract: vol2 by Ken Binmore