For Hobbes, the social contract is the necessary outflowing of reason in action. Conditions in the state of nature are solitary, poor, nasty, brutish, and short, and so to escape the state of nature, collective rationality is invoked to end the war of all against all. In this war, there is no room for the products of civilization, since the rights that do exist in nature only exist insofar as they serve a survival purpose. And of course, this does not describe collective survival, but rather individual survival. Everyone has the right to anything. This is not normative, but is a law that is established by necessity (due to the continuous conflict in the state of nature). The reason this law is invoked is because of the nature of Hobbesian agents. Hobbes supports his views on two points. First, he develops a lengthy and sophisticated account of psychology as being driven by underlying physical mechanisms.

It really is, for Hobbes, merely a matter of deduction. Since human beings are wholly materially objects, we can study how they operate in an exhaustive manner—that is, in the same way we examine other bodies in motion and create mathematical descriptions that always obtain in the physical world, so can we with humans. This is what Hobbes is after. It is this continued motion that sets the passions into play. And as a result of scarcity and equality, every solution to escape the state of nature will inevitably fail until agents realize (seemingly at the same time) that completely following the rights of nature is ultimately inimical to their interests, and so they consent to a compact, which creates the Leviathan, the source of order, stability, and is the ground of morality and justice. This contract creates asymmetric obligations, in that the right to revolution is not kept with the citizens. Instead, the only way to nullify the contract (individually) is if the sovereign utterly fails in protecting the lives of his subjects, for that exactly is the entire justification of the social contract, namely that the social contract is better than the state of nature, for in the state of nature, the state of war is continuous, and any other state of affairs created by the social contract is a state of peace.

Locke’s conception of the social contract, like Hobbes’, is based on the notion of consent, although Locke’s account is far more robust. On his view, the asymmetry dissolves, and citizens have the ability to revolt if the government refuses to abide by the terms of the contract, although he recognizes that this is fairly tendentious because there never is any clear delineation between when revolution is unacceptable versus acceptable. This will be explored later. The key difference between Hobbes and Locke is that Locke is very clear that morality is grounded in eternal law, which is revealed to us by the exercise of reason. Reason is the method by which we come to an understanding of natural law and its obligations. What causes us to form the state are the inconveniences that arise from the state of nature. Of course, in Locke’s time, the word ‘inconveniences’ was much stronger than it is today. Nevertheless, the state of nature is a state of perfect freedom, equality, and the laws of nature. Since the liberty afforded is not one of license, every individual has the right of executive power to enforce the laws of nature, even if aggression did not take place against that particular person. Acts of aggression result in alientation of rights through the state of awr. Thus, the aggressor can be treated like a wild animal—killed, if necessary. But partiality and the problems of the practical administration of justice drive tehe formation of the state, which must be formed through the free consent of the people because of self-ownership and equality.

The state, then, exists to promote the public good by being a neutral third party executor of justice, which is defined in terms of property rights, for that is what Locke’s analysis of rights I, namely that all rights are actually property rights, and so the most obvious model to adopt to respect at least a good number of our moral intuitions would be self-ownership, although since God is the ultimate owner, it is more like a derivative form of ownership that is constrained by God’s commands as revealed through the laws of nature.

Locke’s view has more plausibility just because of his grounding of morality. Regardless of whether one approves of his theistic foundations, other more modern thinkers have removed God from the equation and provided a purely secular account of natural law, so that should not overly count against him. Secondly, he does provide extra moral reasoning in the form of through experiments just in case one does not agree with the ontological foundations. His descriptive account of the state of nature also seems to be far more accurate—both anthropologically and philosophically, although it too is plagued with errors. In terms of relative standing, Locke’s account takes our moral sensibilities into account, provides an adequate description of the state of nature that is not predicated on wildly implausible metaphysical assumptions that includes an obsession with geometric axioms and deductive certainty afforded by them, and describes a transition that is not beset with a host of game-theoretic problems. Hobbes’ sovereign, on the other hand, is free to engage in whatever activities he chooses because his actions literally determine right and wrong. Thus, the sovereign is susceptible to the Euthyphro dilemma: is it good because he does it, or does he do it because it is good? Either option seems devastating to his account. Furthermore, his psychological conception of humans is very questionable, and so any conclusions reached should be shadowed in skepticism. He also fails to provide an adequate account of the transition out of the state of nature that is plausible (given the agents posited), and has no real basis for using terminology such as rights, justice, obligation, and  the like, since political philosophy is concerned with normative justification as opposed to mere historical or anthropological description, Hobbes’ account seems to lack the sort of force required in this endeavor.