Social contract theory is a major tenant of liberalism. Liberalism is defined as a general philosophy where the value of liberty must be measured as the highest political good in a society. Social contract theory works as one approach to legitimate liberty in society. For centuries theorists from Thomas Hobbes to John Rawls have tried to argue for a society using the theoretical concept of the social contract between all citizens and their state.
The social contract is merely a theoretical term. Therefore, an advantage to the social contract is the framework can be worked on in the abstract, meaning that theorists can create elaborate, just frameworks for society. This has allowed philosophers such as John Locke or political theorists such as John Rawls to vigorously work on the fairest, most just social contract. Although one might find theory or abstract thinking a disadvantage, historically speaking, these theorists have influenced liberalism as a whole. For example, it is hard to consider the American or French Revolution without the work of Thomas Hobbes, John Locke or Jean-Jacques Rousseau.
The Contract's Inclusiveness
The social contract's theoretical incentive is that a social contract strives for the fairest and most inclusive society. For example, Thomas Hobbes, 1588-1679, argued in his seminal work, "Leviathan," that political authority needs to be rested on one sole authority that all people consent toward. For Hobbes, human beings constantly war with each other over survival and resources, limiting each person's life and liberty. Through a legitimate government via a social contract, no war exists between people since all political power is rested in an entity, such as a government, that all people consent to. Hence, liberty is enhanced for all.
The Contract's Fairness
Proponents of social contract theory argue that many theorists create frameworks that are fairer than current society. The fairness comes from the fact that all people under a social contract framework would work toward a society where they or others would not be harmed from gross inequality. For example, John Rawls, 1921-2002, argued that social contract theory works by stating a position, or the Original Position in Rawls framework, where individuals would want to live in a society where they would not want gross inequality (political, social, economic) applied against them. Hence, everyone would want to live in a society where, for more or less, people are equal to each other thanks to a social contract.
The main and central advantage to social contract theory is the legitimation of government. When Thomas Hobbes first considered the idea of a social contract, it was when his country of England began the English Civil War. During the English Civil War, the monarchy of England was at war with proponents of the parliamentary system of England. For Hobbes, Locke or Rousseau, the idea of the social contract was to make sure a government could be agreed upon by all citizens to avoid all types of civil wars or tyrannies.