Given the essentiality of peace and prosperity to the quality of human life, the significance of private property can hardly be ignored. Its greatest significance in the eyes of commentators, however, seems rooted in the impetus it gives to the liberty of the individual to pursue happiness – the highest good of human life and society regarded by Aristotle. According to Platt, private property first brings about the ownership of the individual over his own person which is doubtlessly by far the most substantial property in kind, while certainly not merely a property. Such ownership gives rise to the freedom of human person, without which the individual can hardly escape the fate of being either a soldier to be slaughtered on the battle field or a prisoner locked by the land he cultivates. The residents of the city were the first to enjoy this freedom. They are all equal in terms of civil rights. Then freedom was extended to those peasants who escaped their countryside prisons and lived in the city for more than a year. All of their obligations from their feudal bonds were legally released. They thus gained the status of freemen. Such freedom lured more and more peasants to flee the manor and flood into the city. Clearly, it is only a matter of time for all peasants to acquire ownership over their own person. H. Pirenne indicates that, free transaction of land went on shoulder by shoulder with personal freedom. Such free transaction is inevitable for it is simply impossible for any land to sit idle in a merchant community. (Note that the “freedom” these authors speak of is the one at the time of the municipality. It cannot be therefore expected to be precisely the same as the freedom we see today. It is nevertheless of grandeur. One may even argue that in some areas it is even greater than what we have today). Without the private ownership of land, the then second most substantial property, such free transaction does not seem possible. With such trend the individual’s ownership over the fruit of his labour inevitably came into being, which provides the individual with more leeway in personal flourishing. Bethell maintains that private property entails the autonomy of the individual to make his own life plans.
In Locke’s words, property rights enable the individual to pursue the way of life he sees best fit. Such liberty is of most importance for the satisfaction of the deepest human desire – happiness. It is therefore central to the existence and maintenance of society. It can be seen that, for Locke, liberty constitutes the most profound justification of property rights. And, grounded in his theory of liberty, Locke developed his theory of property rights. Since the doctrine of natural law is the philosophical foundation of all of Locke’s thoughts, it thus also constitutes the ultimate foundation of his theory of property rights. According to Professor Glen Fox, the doctrine of natural law has inspired a variety of theories of property rights in Lockean liberalism and modern libertarianism, all arguing for unqualified property rights from different angles. For this reason, he categorizes them into the natural law tradition of property rights theories.
The idea of liberty is seemingly of extraordinary resonance. This resonance, however, does not seem to have rendered the idea of private property immune to criticisms, despite the intimate connection between it and liberty in the eyes of many commentators. It has always been confronted with challenges ever since its emergence. On the other hand, however, it does prevent the early opponents of property rights from attacking the idea itself. These opponents do not ground their rejection to private property on its contribution to liberty. Quite the contrary, they assert that private property jeopardizes liberty. It is the cause for society to establish a political authority which is a chain we impose on our own neck, asserts Jean-Jacques Rousseau. Karl Marx recognizes that some form of private property is necessary. The private ownership of the means of production, however, must be eliminated, for it reduces the worker to “an appendage of the machine”. Such notions initially attracted a surprisingly sizable audience. The size of Marx’s audience is especially remarkable. It is large enough to give rise to communist regimes, first in Russia, and then in many nations and regions across a fairly large portion of the world. Such attraction, however, soon faded after these regimes had revealed their exceeding cruelty that brutally supresses individual liberty.
 Aristotle, The Nicomachean ethics. (London: Penguin Books, 2004), 1095a, 20.
 Rutherford Platt, Land Use and Society –Geography, Law, and Public Policy, revised ed. (London: Island Press, 2004) pp. 77.
 H. Pirenne, Medieval Cities: Their Origins and the Revival of Trade, (Princeton: Princeton University Press), p.10.
 Tom Bethell, The Noblest Triumph-Property and Prosperity through the Ages, (New York: St. Martin’s Press, 1988), p.10
 John Locke, “Second Treatise of Government” in Two Treatise of Government, Ed., Peter Laslett, (Cambridge: Cambridge University Press, 2008), II, p. 77.
 Glenn Fox, The Origins, Nature, and Content of the Right to Property: Five Economic Solitudes, (Ottawa: Canadian Journal of Agricultural Economics, Volume 60, Issue 1, March 2012), pp. 15-22.
 Jean-Jacques Rousseau, “Discourse on the Origin of Inequality” in The Basic Political Writings, trans. Donald A. Cress (Indianapolis: Hackett, 1987), pp. 69-70.
 Karl Marx and Friedrich Engels, “The Communist Manifesto” in Selected Writings, ed. Lawrence H. Simon (Indianapolis: Hackett, 1994), p. 164.