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Personal and proprietary interests

5.1. Characteristics of proprietary interests

In this chapter, we outline the distinctive features of property interests and how they differ from non-proprietary interests in things. Most of these points come up again in other chapters (some of them in more detail): the object of this chapter is to draw together some recurrent themes.

5.1.1. General enforceability

We saw in Chapter 2 that the essential characteristic that distinguishes proprietary interests in things from non-proprietary interests is their range of enforceability. A non-proprietary interest is essentially bilateral: generally only one other person is under a duty correlative to the right held by the right holder. A proprietary interest, on the other hand, is generally enforceable: if I hold a property right, everyone in the world (or, in the case of some types of right, everyone in the world except a privileged class) has a correlative duty. The classic illustration of the general enforceability principle is provided by the decision in Hill v. Tupper, extracted below, where the court held that, where a canal company which had (among its other rights in the canal) an exclusive right to put pleasure boats for hire on the canal, transferred that right to Hill, Hill became entitled to prevent the canal company from also putting boats on the canal for hire, but was not entitled to prevent Tupper, a stranger, from doing so. One of the ingredients of the canal company’s proprietary interest in the canal was a proprietary right to put pleasure boats for hire on the canal, but it could not break that right off from its proprietary bundle in such a way that the right remained proprietary when transferred to Hill. As against the canal company, Hill had the exclusive right to put pleasure boats on the canal (so, for example, he could require the canal company to prevent anyone else doing so) but it was enforceable only against the canal company, not against Tupper. It was a personal right, not a property right.

The principle that a proprietary interest is generally enforceable is as near absolute as any principle in English property law. Its obverse – that non-property interests in things are enforceable only bilaterally – requires some qualification, however. First, contract and constructive trust rules may allow a non-proprietary

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