Modern philosophers abandon the idea of the polis as highest form of human association and instead see the founding of city, (now the commonwealth), as a consequence of certain practical /natural circumstances that cannot be overcome by the individual alone. Hence, one must enter a political association or commonwealth. There are no families, no towns, no history, no culture, no common morality only individuals who must decide what is in their own best interest, i.e. if it is rational to join with others in this kind of cooperative venture, namely, a commonwealth or civil state.Hobbes and Rousseau see this challenge facing the individual, the social contract and the sovereign very differently. What are the similarities and differences between them? How do they employ the concept of equality in their approaches? If rational self-interest ties people to the commonwealth, is it sufficient to keep them together? What is their concept of political authority? Why should citizen's