The thesis of this brief paper is straightforward, although not uncontroversial: The moral foundation of property, both as a concept and as an institution, is human flourishing. In the remainder of my remarks I will explain what I mean by human flourishing, as I use the term, and I will distinguish human flourishing from welfare as that term is commonly used today by economists and legal analysts. I will then briefly illustrate the approach through an example. Private property ordinarily triggers notions of individual rights, not social obligations. After all, the core function of private property, at least according to conventional lore, is to insulate individuals from the demands of society both in its organised political form and its non-political collective form. Of course, the common law has long recognised limits on the exercise of property rights, limits that grow out of the needs of others in cases of conflicting land uses. The obvious example is the common law of nuisance, which courts developed using the ancient maxim sic utere tuo ut alienum non laedas (“use your land in such a way as not to injure the land of others”) as their guiding principle. But such limits on property rights are considered the exception, not the rule, the periphery rather than the core. The core image of property rights, in the minds of many people, is that the owner has a right to exclude others and owes no further obligation to them. On this view trespass is the paradigmatic cause of action in the law of property. Hence if another intentionally commits trespass upon my land after I have refused permission to pass across it, the trespasser is properly liable for punitive damages even though only trivial damage was done to my property. That image is highly misleading. The right to exclude itself, thought by many to be the most important twig in the so-called bundle of rights, is subject to many exceptions, both at common law and by virtue of statutory or constitutional provisions. For example, the common law requires landowners to permit police to enter privately owned land to prevent a crime from being committed or to make an arrest. More generally, property owners owe far more responsibilities to others, both owners and non-owners, than the conventional imagery of property rights suggests. Property rights are inherently relational, and because of this characteristic, owners necessarily owe obligations to others. But the responsibility, or obligation, dimension of private ownership has been sorely under-theorised. In this brief paper I shall outline a theory of property that emphasises the obligations that owners owe to others, specifically, to certain members of the various communities to which they belong. These obligations vary in different contexts and at different times. As society has grown more complex and more interdependent, the obligations have thickened. Capturing all of these obligations under one theoretical umbrella, one may speak of a social-obligation norm that the law does and should impose on owners. This norm, I want to stress, in inherent in the concept of ownership itself. This is an important point because it means that when the law, whether by way of statutes, administrative action, or judicial decisions, announces some restriction on an owner’s use of her land or building, insofar as that announcement restates what is already part of the social-obligation norm, it is simply a legal recognition of a restriction that is inherent in the concept of ownership rather than being externally imposed and engrafted upon the owner’s bundle of right. The basis of this norm is human flourishing. The social-obligation theory builds on the claim that the basic purpose of property is to enable individual to achieve human flourishing. The theory further builds on Amartya Sen’s famous insight that flourishing is a matter of what a person is able to do rather than what he has. That is, the well-lived life should be measured by a person’s capabilities rather than by a person’s possession or by the satisfaction of his subjective preferences. Before developing the social obligation of ownership, I must first explain the foundational norm of human flourishing a bit further
