Emerging nationalism was one of the primary forces in shaping change in Europe throughout the late 18th and into the 19th centuries, in no small part due to the enormous influence of Jean-Jacques Rousseau’s Of the Social Contract, Or Principles of Political Right, written in 1762 in France. Rousseau’s Social Contract attempted to answer the question, “is it possible to establish some just and reliable rule of administration in civil affairs?” Rousseau explicitly laid out that his essay was an attempt to find a justification for the institution of government over man—his bondage—since government is a fact of life, but that most governments seemed to be in possession of arbitrary authority. Given that governments and nations existed throughout the world, if man was going to be limited by them, there should naturally arises a tendency to question how this can be legitimate.
Rousseau believed that people would give up their freedom they enjoy in nature only in order that they secure their own advantage thereby. Rousseau denies that rights can be establish by facts, just as David Hume did; as such, he notes that the existence of slavery is not evidence enough to induce that slavery is a part of the natural order. Rousseau dispatches with the moral principle that might makes right, understanding that if this were true, right would add nothing to might, given that a change in one necessarily means a change in the other, which is a flimsy basis for a right.
Rousseau notes it is odd to extend the principle that an individual can alienate his freedom in exchange for subsistence—that is, to sell himself into slavery—to a king, since subjects do not depend on their king for their daily bread, rather the reverse is true. Men would not give up their freedom in order “that their property also shall be taken.” Rousseau ultimately denies even the ability to alienate one’s liberty and voluntarily become a slave, since this would be to renounce the very essence of humanity and be a self-contradictory proposition. Rousseau denies Dutch jurist Hugo Grotius’s claim that victors in war have the right to demand slavery from the subjects of their conquered for, since wars are between state and state, rather than between individuals, so the only spoils that rightfully belong to the victorious state are the possessions of the vanquished state; to assert otherwise is simply an extension of the earlier-refuted maxim that might makes right. 
In Chapter V, Rousseau attempts to establish what constitutes a people, or a nation, since Grotius asserts that a people can alienate itself to a king, meaning it had to have been a body politic already in order to have deliberated and made such a decision. If these individuals had not been a body politic, to establish authority over every one, every individual would have had to unanimously vote to give up their liberties, for the ability of a majority to bind a minority is only operative anterior to the creation of a body politic. Here, Rousseau elucidates his social contract theory, whereby men determine that the state of nature being harsh and unforgiving with each individual acting only with regard to his own self-interest, they would find it in their best interest to form an association capable of protecting their persons and property by using the “whole force of the community” to protect each individual member. Rousseau moves on in Chapter VII to note that a social compact having been agreed to, and a collective body having been formed, it is the sovereign which takes on the role of the individual, in that it under no obligation to be bound to itself, namely that it cannot “impose on itself a law it cannot transgress”; in essence, it is a body of unlimited authority. Rousseau also stipulates that individuals give up all rights to property they were in possession of to the State, which is of little significant to him because possession of property by the state is actually “more secure.”
Rousseau comes to the conclusion that it is nationhood, under the collective agreement that creates a republic, that defines a people; and all of the corresponding duties attendant to it are one’s highest political duties. In a footnote on page 171, Rousseau notes that although once a social contract has been agreed to, unanimity is no longer necessary to give force to the general will, it is necessary that everyone be able to vote on what actions the general will should take, because to do otherwise makes it an expression of a particular will rather than the true general will. Democracy, then, becomes an important aspect of the legitimacy of acts of the State in reflecting the general will of the people rather than the fancies of its leaders.
The significance of Rousseau’s Social Contract is that it gives parameters by which one can judge the legitimacy of governments in both their structure and substance. Governments must usually be democratic, because if they were not it means they are not attempting to ascertain the general will of the people. Similarly, leaders must act in accordance with the general will and those who contravene it are illegitimate; leaders who continue to act against popular sentiment have no right to rule under the social contract. Additionally, it seems to follow from Rousseau’s footnote on page 169 that government should redistribute wealth in order that they function efficiently, because too much inequality renders the social state only advantageous to the rich. Furthermore, Rousseau’s ideas significantly impacted the French Revolutionaries of the late 18th century, whose motto was Liberté, Égalité, Fraternité. These revolutionaries rejected the authority of the king since he was contravening the above-mentioned principles and subordinating the general will and common good to his own particular good. Equality and reciprocity, moving forward, become important foundations of Rousseau’s political philosophy and the modern nation-state. Rousseau’s ideas reflected and reinforced the movements in the late 18th century, such as in France, and those throughout the 19th century to create unitary states, in which the sovereign possessed full authority and plenary power, rather than enduring in the fragmented, decentralized situation many European nations like Germany had been in. This drive attempted to shed the arbitrary authorities of kings, princes, and other leaders by establishing anew a modern nation representative of the general will of the people rather than the special interest of the king.
 Jean-Jacques Rousseau, The Social Contract and The First and Second Discourses, ed. Susan Dunn (New Haven; London: Yale University Press, 2002), 155.
Ibid., 156. In Rousseau’s words: “Man was born free, and everywhere he is in chains….How has this change come about? I do not know. What can make it legitimate? I believe I can settle this question.”
 Ibid., 156-158. Likewise, Rousseau says, “If one is compelled to obey by force, there is no need to obey from duty’ and if one is no longer forced to obey, obligation is at an end.”
 Ibid., 159-161. The convention of taking slaves rather than killing enemy combatants presupposes a state of war and terminates at the establishment of peace, so this cannot justify an absolute authority of a ruler over his subjects either.
 Ibid., 162.
 Ibid., 163.
 Ibid., 167.
 Here, Rousseau says “Under bad governments, this equality is only apparent and illusory; it serves only to keep the poor in their misery and the rich in their usurpations. In fact, laws are always useful to those who possess and injurious to those that have nothing; whence it follows that the social state is advantageous to men only so far as they have something, and none of them has too much.”