Shakespeare's The Merchant of Venice has been widely read as a play about law and justice. Shylock's defeat, however, demonstrates that Venice is governed not so much by a law that safeguards human equality as by a social contract that highlights differences in terms of gender, race, and class. The Merchant of Venice consists of three sub-plots: the bond plot, the casket plot, and the ring plot. All of them deal with the social contract, which has been considered the foundation of social life and whose goal has been directed toward the common good. Today these concepts are confronted by critiques mainly from feminist and racial perspectives. It is generally recognized that the naturalization of the social contract has justified gender and racial inequality. Drawing upon Monique Wittig's theory of "the straight mind," this paper explores the social contract in the three sub-plots of The Merchant of Venice. The paper also analyzes Portia's role in this play to examine whether she has subverted the Venetian social contract or has submitted to it.