Social Contract Theory, is one of the oldest philosophical theories on the origin of state .The original inspiration for this notion is said to have derived from the bible, covenant between God and Abraham and later by the Sophists in Greece, but it is mostly brought up by the writings of Thomas Hobbes, John Locke, and Jean-Jacques Rousseau. The social contract is moral and/or political obligation dependent upon a contract or agreement between the people to form society. The social contract theory has three main stages of progression, namely- state of nature, contract or covenant and civil society. These three stages provide the basic differences between the theories of Thomas Hobbes, John Locke, and Jean-Jacques Rousseau.
THOMAS HOBBE’S THEORY OF THE SOCIAL CONTRACT
Thomas Hobbes (1588-1679) was an English philosopher and political thinker. The English civil war became the back drop for all his writings. In the context of a number of overlapping conflicts Hobbes wrote various versions of his political theory, begning with The elements of Law (1630s),De Cive(1642),and Leviathan (1651). 
According to Hobbes, the state of nature represented the interactions of human beings with each other in the absence of any kind of relations of political authority. In other words the state of nature represented a state of war. Hobbes believed that the human beings in the state of nature were concerned only with their desires  . The human nature here was selfish. No person was superior over the other. Hobbes further said that the desire to acquire power never ended and thus it aggravated the state of war where everyone was trying to ensure that no one will stop them from fulfilling their desires of glory. Thus creating a situation favorable for long-term projects, like farming, industry, etc. became impossible. It was a situation of continuous fear and violence.
“In such condition there is no place for industry, because the fruit thereof is uncertain: and consequently no culture of the earth; no navigation, nor use of commodities that may be imported by sea; no commodious building; no instruments of moving and removing such things as require much force; no knowledge of the face of the earth; no account of time; no arts; no letters; no society; and which is worst of all, continual fear, and danger of violent death; and the life of man, solitary, poor, nasty, brutish, and short.”
Such a state called for some laws to be enforced. Hence the need arose to have an authority that would enforce the laws of nature and help man to fulfill his desires in a more efficient way. This led to the signing of the Social Contract between men leading to the formation of a state as well as a sovereign. In such a state or commonwealth, as stated by Hobbes, men authorized a particular individual or a group of individuals to perform all actions. Moreover men also gave up certain rights on a condition that such rights were also given up by the entire multitude.
“A commonwealth is said to be instituted, when a multitude of men do Agree, and Covenant, every one, with every one, that to whatsoever Man, or Assembly of Men, shall be given by the major part, the Right to Present the Person of them all (that is to say, to be their Representative); every one, as well he that Voted for it, as he that Voted against it, shall Authorize all the Actions and Judgments , of that Man, or Assembly of Men, in the same manner, as if they were his own, to the end, to live peaceably amongst themselves, and be protected against other men.”
Hobbes sovereign had absolute authority. His judgments and actions could not be questioned as this sovereign was not a part of the social contract. Opposing this sovereign meant opposing oneself as this sovereign represented the people itself. The only right that men had against this sovereign was the right to life or self-preservation.
JOHN LOCKE’S THEORY OF THE SOCIAL CONTRACT
Initially, although John Locke (1632-1704) believed in the absolute power of the monarchy and religious uniformity, his stance changed drastically later. His changed stance is best put forward in the work Two Treatises of Government.
Unlike, Hobbes for whom the state of nature is a state of war, Locke’s state of the nature is the state of peace, Good Will, Mutual Assistance, and Preservation.’  His theory brings out that man is a wise, sociable being who can judge the ill effects of going to war with men. It can be noted that Locke’s has positive view of the state of nature and of human beings.
Locke brings in the concept of private property which in all probability leads to inequalities of wealth. In order to ensure the security of the natural laws, and the inequality of wealth, man to enter into a community governed by a set of laws and the government. Locke disbelieves in censorship by the state, and says that state must exist and function separately from the people. The main goal of state is to ensure personal safety and protection of personal property rights. If it fails so he empowered people to revolt against the state, and, to go for a revolution if it abuses its authority.
Hence unlike Hobbes, Locke’s government is not absolute. Its powers are limited to an extent where it starts encroaching on public good.
JEAN JACQUES ROUSSEAU’S THEORY OF THE SOCIAL CONTRACT
Jean Jacques Rousseau (1712-1778) remains one of the first thinkers to offer us a strong critique of modern social and political institutions in the name of the modern values of equality, liberty and democracy. 
Rousseau’s theory on the state of nature shows in progressive stages how men, from behaving like animals, transform themselves into a society. This society, according to Rousseau, is not civil at all as it gives rise to more corruption and negative feelings in Man’s mind. Thus Rousseau’s view point differs from Hobbes or Locke who believe in the transformation of men from the state of nature to a more ‘civil’ society. Rousseau in his theory favours men in the state of nature in which they only have natural differences rather than having political, social or economic differences. But “however we have no moral liberty in the state of nature, because we have not yet developed a moral sense. This moral sense can only be born in society, and we need to establish a society in which, not only do we preserve the liberty of the state of nature, but also provide the conditions for us to achieve moral freedom.”  So in order to solve this problem men enter into a social contract. The new political entity which is formed as a result of this contract reflects and works for the general will. This general will leads to the protection of individual liberty which as a corollary leads to the removal of economic, social and political inequality. Thus; Rousseau says; that it is only because of this general will that the sovereign is indivisible, inalienable and infallible.  Because of this people are ready to lay down even their right to self-preservation. This concept, as clearly seen, is a stark contrast to Hobbes and Locke’s theory.
In this way one sees that all three – Hobbes, Locke and Rousseau differ in their theories of the Social Contract. All three of them start off by describing the state of nature and man’s progression into ‘civil’ society. But, however, the reasons which force man into such a society differ from one author to the other. This, in turn, leads them to have a contrasting view point on the powers and duties of the sovereign as well the state. Despite the differences in their viewpoints, their theories have one common thread running through them which reflects that The Social Contract is the best way to maintain peace and order. Though this end propagated by them is the same, the means and prerequisite conditions differ.