There is a general form of social contract theories, which is:

I chooses R in M and this gives I* reason to endorse and comply with R in the real world insofar as the reasons I has for choosing R in M are (or can be) shared by I*.^[5]

With M being the deliberative setting; R rules, principles or institutions; I the (hypothetical) people in original position or state of nature making the social contract; and I* being the individuals in the real world following the social contract.^[5]

Social contract formulations are preserved in many of the world's oldest records.^[6] The Indian Buddhist text of the second century BC Mahāvastu recounts the legend of Mahasammata. The story goes as follows:

In the early days of the cosmic cycle mankind lived on an immaterial plane, dancing on air in a sort of fairyland, where there was no need of food or clothing, and no private property, family, government or laws. Then gradually the process of cosmic decay began its work, and mankind became earthbound, and felt the need of food and shelter. As men lost their primeval glory, distinctions of class arose, and they entered into agreements with one another, accepting the institution of private property and the family. With this theft, murder, adultery, and other crime began, and so the people met together and decided to appoint one man from among them to maintain order in return for a share of the produce of their fields and herds. He was called "the Great Chosen One" (Mahasammata), and he received the title of raja because he pleased the people.^[7]

In his rock edicts, the Indian Buddhist king Asoka was said to have argued for a broad and far-reaching social contract.^{[citation needed]} The Buddhist vinaya also reflects social contracts expected of the monks; one such instance is when the people of a certain town complained about monks felling saka trees, the Buddha tells his monks that they must stop and give way to social norms.^{[citation needed]}

Epicurus in the fourth century BC seemed to have had a strong sense of social contract, with justice and law being rooted in mutual agreement and advantage, as evidenced by these lines, among others, from his Principal Doctrines (see also Epicurean ethics):

31. Natural justice is a pledge of reciprocal benefit, to prevent one man from harming or being harmed by another.

32. Those animals which are incapable of making binding agreements with one another not to inflict nor suffer harm are without either justice or injustice; and likewise for those peoples who either could not or would not form binding agreements not to inflict nor suffer harm.

33. There never was such a thing as absolute justice, but only agreements made in mutual dealings among men in whatever places at various times providing against the infliction or suffering of harm.^[8]

The concept of the social contract was originally posed by Glaucon, as described by Plato in The Republic, Book II.

They say that to do injustice is, by nature, good; to suffer injustice, evil; but that the evil is greater than the good. And so when men have both done and suffered injustice and have had experience of both, not being able to avoid the one and obtain the other, they think that they had better agree among themselves to have neither; hence there arise laws and mutual covenants; and that which is ordained by law is termed by them lawful and just. This they affirm to be the origin and nature of justice;—it is a mean or compromise, between the best of all, which is to do injustice and not be punished, and the worst of all, which is to suffer injustice without the power of retaliation; and justice, being at a middle point between the two, is tolerated not as a good, but as the lesser evil, and honoured by reason of the inability of men to do injustice. For no man who is worthy to be called a man would ever submit to such an agreement if he were able to resist; he would be mad if he did. Such is the received account, Socrates, of the nature and origin of justice.^[9]

The social contract theory also appears in Crito, another dialogue from Plato. Over time, the social contract theory became more widespread after Epicurus (341–270 BC), the first philosopher who saw justice as a social contract, and not as existing in Nature due to divine intervention (see below and also Epicurean ethics), decided to bring the theory to the forefront of his society. As time went on, philosophers of traditional political and social thought, such as Locke, Hobbes, and Rousseau put forward their opinions on social contract, which then caused the topic to become much more mainstream.^{[citation needed]}

Quentin Skinner has argued that several critical modern innovations in contract theory are found in the writings from French Calvinists and Huguenots, whose work in turn was invoked by writers in the Low Countries who objected to their subjection to Spain and, later still, by Catholics in England.^[10] Francisco Suárez (1548–1617), from the School of Salamanca, might be considered an early theorist of the social contract, theorizing natural law in an attempt to limit the divine right of absolute monarchy. All of these groups were led to articulate notions of popular sovereignty by means of a social covenant or contract, and all of these arguments began with proto-"state of nature" arguments, to the effect that the basis of politics is that everyone is by nature free of subjection to any government.

These arguments, however, relied on a corporatist theory found in Roman law, according to which "a populus" can exist as a distinct legal entity. Thus, these arguments held that a group of people can join a government because it has the capacity to exercise a single will and make decisions with a single voice in the absence of sovereign authority—a notion rejected by Hobbes and later contract theorists.

The first modern philosopher to articulate a detailed contract theory was Thomas Hobbes (1588–1679). According to Hobbes, the lives of individuals in the state of nature were "solitary, poor, nasty, brutish and short", a state in which self-interest and the absence of rights and contracts prevented the "social", or society. Life was "anarchic" (without leadership or the concept of sovereignty). Individuals in the state of nature were apolitical and asocial. This state of nature is followed by the social contract.

The social contract was seen as an "occurrence" during which individuals came together and ceded some of their individual rights so that others would cede theirs.^[11] This resulted in the establishment of the state—a sovereign entity like the individuals (now under its rule) used to be, which would create laws to regulate social interactions. Human life was thus no longer "a war of all against all".

The state system, which grew out of the social contract, was, however, also anarchic (without leadership). Just as the individuals in the state of nature had been sovereigns and thus guided by self-interest and the absence of rights, so states now acted in their self-interest in competition with each other. Just like the state of nature, states were thus bound to be in conflict because there was no sovereign over and above the state (more powerful) capable of imposing some system such as social-contract laws on everyone by force. Indeed, Hobbes' work helped to serve as a basis for the realism theories of international relations, advanced by E. H. Carr and Hans Morgenthau. Hobbes wrote in Leviathan that humans ("we") need the "terrour of some Power" otherwise humans will not heed the law of reciprocity, "(in summe) doing to others, as wee would be done to".^[12]

John Locke's conception of the social contract differed from Hobbes' in several fundamental ways, retaining only the central notion that individuals in a state of nature would willingly come together to form a state. Locke believed that individuals in a state of nature would be bound morally, by the Law of Nature, in which man has the "power... to preserve his property; that is, his life, liberty and estate against the injuries and attempts of other men". Without government to defend them against those seeking to injure or enslave them, Locke further believed people would have no security in their rights and would live in fear. Individuals, to Locke, would only agree to form a state that would provide, in part, a "neutral judge", acting to protect the lives, liberty, and property of those who lived within it.^[13][14]

While Hobbes argued for near-absolute authority, Locke argued for inviolate freedom under law in his Second Treatise of Government. Locke argued that a government's legitimacy comes from the citizens' delegation to the government of their absolute right of violence (reserving the inalienable right of self-defense or "self-preservation"), along with elements of other rights (e.g. property will be liable to taxation) as necessary to achieve the goal of security through granting the state a monopoly of violence, whereby the government, as an impartial judge, may use the collective force of the populace to administer and enforce the law, rather than each man acting as his own judge, jury, and executioner—the condition in the state of nature.^{[citation needed]}

Jean-Jacques Rousseau (1712–1778), in his influential 1762 treatise The Social Contract, outlined a different version of social-contract theory, as the foundations of society based on the sovereignty of the "general will".

Rousseau's political theory differs in important ways from that of Locke and Hobbes. Rousseau's collectivist conception is most evident in his development of the "luminous conception" (which he credited to Denis Diderot) of the "general will". Summarised, the "general will" is the power of all the citizens' collective interest—not to be confused with their individual interests.

Although Rousseau wrote that the British were perhaps at the time the freest people on earth, he did not approve of their representative government, nor any form of representative government. Rousseau believed that society was only legitimate when the sovereign (i.e. the "general will") were the sole legislators. He also stated that the individual must accept "the total alienation to the whole community of each associate with all his rights".^[15] In short, Rousseau meant that in order for the social contract to work, individuals must forfeit their rights to the whole so that such conditions were "equal for all".^[16]

[The social contract] can be reduced to the following terms: Each of us puts his person and all his power in common under the supreme direction of the general will; and in a body, we receive each member as an indivisible part of the whole.^[17]

Rousseau's other writings assert that his striking phrase that man must "be forced to be free"^[18] should be understood^{[according to whom?]} this way: since the indivisible and inalienable popular sovereignty decides what is good for the whole, if an individual rejects this "civil liberty"^[19] in place of "natural liberty"^[19] and self interest, disobeying the law, he will be forced to listen to what was decided when the people acted as a collective (as citizens). Thus the law, inasmuch as it is created by the people acting as a body, is not a limitation of individual freedom, but rather its expression. The individual, as a citizen, explicitly agreed to be constrained if, as a private individual, he did not respect his own will as formulated in the general will.

Because laws represent the restraint of "natural liberty",^[19] they represent the leap made from humans in the state of nature into civil society. In this sense, the law is a civilizing force. Therefore, Rousseau believed that the laws that govern a people help to mould their character.

Rousseau also analyses the social contract in terms of risk management,^[20] thus suggesting the origins of the state as a form of mutual insurance.

While Rousseau's social contract is based on popular sovereignty and not on individual sovereignty, there are other theories espoused by individualists, libertarians, and anarchists that do not involve agreeing to anything more than negative rights and creates only a limited state, if any.

Pierre-Joseph Proudhon (1809–1865) advocated a conception of social contract that did not involve an individual surrendering sovereignty to others. According to him, the social contract was not between individuals and the state, but rather among individuals who refrain from coercing or governing each other, each one maintaining complete sovereignty upon him- or herself:

What really is the Social Contract? An agreement of the citizen with the government? No, that would mean but the continuation of [Rousseau's] idea. The social contract is an agreement of man with man; an agreement from which must result what we call society. In this, the notion of commutative justice, first brought forward by the primitive fact of exchange, ... is substituted for that of distributive justice ... Translating these words, contract, commutative justice, which are the language of the law, into the language of business, and you have commerce, that is to say, in its highest significance, the act by which man and man declare themselves essentially producers, and abdicate all pretension to govern each other.

Building on the work of Immanuel Kant with its presumption of limits on the state,^[21] John Rawls (1921–2002), in A Theory of Justice (1971), proposed a contractarian approach whereby rational people in a hypothetical "original position" would set aside their individual preferences and capacities under a "veil of ignorance" and agree to certain general principles of justice and legal organization. This idea is also used as a game-theoretical formalization of the notion of fairness.

David Gauthier's "neo-Hobbesian" theory argues that cooperation between two independent and self-interested parties is indeed possible, especially when it comes to understanding morality and politics.^[22] Gauthier notably points out the advantages of cooperation between two parties when it comes to the challenge of the prisoner's dilemma. He proposes that, if two parties were to stick to the original agreed-upon arrangement and morals outlined by the contract, they would both experience an optimal result.^[22][23] In his model for the social contract, factors including trust, rationality, and self-interest keep each party honest and dissuade them from breaking the rules.^[22][23]

Philip Pettit (b. 1945) has argued, in Republicanism: A Theory of Freedom and Government (1997), that the theory of social contract, classically based on the consent of the governed, should be modified. Instead of arguing for explicit consent, which can always be manufactured, Pettit argues that the absence of an effective rebellion against it is a contract's only legitimacy.

Rousseau argued that societal laws are upheld by the collective will of the citizens whom they represent. Thus, in obeying laws, the citizen "remains free." Within elections, the will of the establishment is the will of the collective. Barring corruption, the legitimacy of the democratic government is absolute.^[24]

In every real democracy, magistracy is not an advantage, but a burdensome charge which cannot justly be imposed on one individual rather than another. The law alone can lay the charge on him on whom the lot falls. For, the conditions being then the same for all, and the choice not depending on any human will, there is no particular application to alter the universality of the law.

According to other social contract theorists, when the government fails to secure their natural rights (Locke) or satisfy the best interests of society, citizens can withdraw their obligation to obey or change the leadership through elections or other means including, when necessary, violence. Locke believed that natural rights were inalienable, and therefore the rule of God superseded government authority, while Rousseau believed that democracy (majority-rule) was the best way to ensure welfare while maintaining individual freedom under the rule of law. The Lockean concept of the social contract was invoked in the United States Declaration of Independence.^[26]

Ideas related to the social contract theory, particularly those of John Locke, intellectually inspired the United States Declaration of Independence. His ideas on every individual’s’ right to ‘life, liberty, and property’ as well as the people’s ‘right to revolt’ were particularly influential.

Locke’s idea that everyone has the right to 'life, liberty, and property' inspired the founding document. The Declaration posits, “We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness”^[27]. The terms ‘life, liberty and the pursuit of happiness’ reflect the ideas of John Locke, who argued for human beings’ natural rights to ‘life, liberty, and property.’ In The Second Treatise of Government, Locke has asserted that “the state of Nature (...) teaches all mankind who will but consult it, that being all equal and independent, no one ought to harm another in his life, health, liberty or possessions^[28]. Since the “state of nature,” which largely means the condition in which humans used to live before civilization^[29], teaches humans to learn that all were born “equal and independent,” Locke emphasizes the inherent equality that exists among human beings, which is reflected in the Declaration's idea that "all men are created equal." Furthermore, Locke argued that men “have rights to life, (...) liberty, or possessions” and that “no one ought to harm another” in these rights. Since the rights to ‘life’ and ‘liberty,’ which constitute two of the three essential rights protected under the social contract, are repeated in the Declaration, Locke’s idea on the natural rights of human beings proves to be influential. As the John Locke Foundation, an independent and nonprofit think tank, establishes, "Locke’s influence can be seen throughout the Declaration of Independence" through the phrase “life, liberty, and the pursuit of happiness.” ^[30]

Locke’s idea of ‘the right to revolt’ was also influential. The Declaration posits that, when the natural rights of human beings are violated under the social contract, “it is the Right of the People to alter or to abolish it, and to institute new Government”^[31]. The usage of the word “right” not only shows how people should be allowed to revolt, but have a moral obligation to overthrow a tyrannical government. In a similar vein, Locke posited that people have ‘the right to revolt’ when their natural rights are violated. According to the philosopher, “Whenever the legislators endeavour to take away and destroy the property of the people, or to reduce them to slavery under arbitrary power, they put themselves into a state of war with the people, who are thereupon absolved from any farther obedience” and gain the “right to resume their original liberty”^[32]. In short, if a government becomes tyrannical, such as by infringing on people’s right to property or on their freedoms, its constituents gain the freedom to overthrow the government at will. This aligns closely with the Declaration’s assertion that people gain the right to “abolish” and to “institute” a new government, showing another way in which Locke's ideas pertaining to the social contract intellectually inspired the Declaration^[33].

Thomas Jefferson, one of the main authors of the Declaration, wrote in a 1825 letter that “Locke,” along with figures such as “Aristotle, Cicero, (...) [and] Sidney,” served as great intellectual foundations for the Declaration, as the text’s “authority rests then on the harmonising sentiments” of such writers^[34]. An explicit mention of Locke’s name, adding to the letter’s admission that his influence proved to be significant in serving as an inspiration for the text, further strengthens the claim that Locke's ideas, particularly those pertaining to the social contract, inspired the Declaration.

An early critic of social contract theory was Rousseau's friend the philosopher David Hume, who in 1742 published an essay "Of Civil Liberty". The second part of this essay, entitled "Of the Original Contract",^[35] stresses that the concept of a "social contract" is a convenient fiction:

As no party, in the present age can well support itself without a philosophical or speculative system of principles annexed to its political or practical one; we accordingly find that each of the factions into which this nation is divided has reared up a fabric of the former kind, in order to protect and cover that scheme of actions which it pursues. ... The one party [defenders of the absolute and divine right of kings, or Tories], by tracing up government to the DEITY, endeavor to render it so sacred and inviolate that it must be little less than sacrilege, however tyrannical it may become, to touch or invade it in the smallest article. The other party [the Whigs, or believers in constitutional monarchy], by founding government altogether on the consent of the PEOPLE suppose that there is a kind of original contract by which the subjects have tacitly reserved the power of resisting their sovereign, whenever they find themselves aggrieved by that authority with which they have for certain purposes voluntarily entrusted him.

Hume argued that consent of the governed was the ideal foundation on which a government should rest, but that it had not actually occurred this way in general.

My intention here is not to exclude the consent of the people from being one just foundation of government where it has place. It is surely the best and most sacred of any. I only contend that it has very seldom had place in any degree and never almost in its full extent. And that therefore some other foundation of government must also be admitted.

The legal scholar Randy Barnett has argued^[36] that, while presence in the territory of a society may be necessary for consent, this does not constitute consent to all rules the society might make regardless of their content. A second condition of consent is that the rules be consistent with underlying principles of justice and the protection of natural and social rights, and have procedures for effective protection of those rights (or liberties). This has also been discussed by O. A. Brownson,^[37] who argued that, in a sense, three "constitutions" are involved: first, the constitution of nature that includes all of what the Founders called "natural law"; second, the constitution of society, an unwritten and commonly understood set of rules for the society formed by a social contract before it establishes a government, by which it does establish the third, a constitution of government. To consent, a necessary condition is that the rules be constitutional in that sense.

The theory of a tacit social contract holds that by remaining in the territory controlled by some society, which usually has a government, people give consent to join that society and be governed by its government if any. This consent is what gives legitimacy to such a government.

Other writers have argued that consent to join the society is not necessarily consent to its government. For that, the government must be set up according to a constitution of government that is consistent with the superior unwritten constitutions of nature and society.^[38]

The theory of an implicit social contract also goes under the principles of explicit consent.^[39] The main difference between tacit consent and explicit consent is that explicit consent is meant to leave no room for misinterpretation. Moreover, you should directly state what it is that you want and the person has to respond in a concise manner that either confirms or denies the proposition.

According to the will theory of contract, a contract is not presumed valid unless all parties voluntarily agree to it, either tacitly or explicitly, without coercion. Lysander Spooner, a 19th-century lawyer who argued before the Supreme Court of the United States and a staunch supporter of a right of contract between individuals, argued in his essay No Treason that a supposed social contract cannot be used to justify governmental actions such as taxation because government will initiate force against anyone who does not wish to enter into such a contract. As a result, he maintains that such an agreement is not voluntary and therefore cannot be considered a legitimate contract at all. As an abolitionist, he made similar arguments about the unconstitutionality of slavery in the US.

Joseph Kary asserts that Modern Anglo-American law, like European civil law, is based on a will theory of contract, according to which all terms of a contract are binding on the parties because they chose those terms for themselves. This was less true when Hobbes wrote Leviathan; at that time more importance was attached to consideration (meaning a mutual exchange of benefits necessary to the formation of a valid contract) and most contracts had implicit terms that arose from the nature of the contractual relationship rather than from the choices made by the parties. Accordingly, it has been argued that social contract theory is more consistent with the contract law of the time of Hobbes and Locke than with the contract law of the present time and that certain features in the social contract which seem anomalous, such as the belief that people are bound by a contract formulated by their distant ancestors, would not have seemed as strange to Hobbes' contemporaries as they do to people today.^[40]