9.1.2.The danger of property

Recognition of new property interests 347

was stolen. For as long as they remain owner their claim will bind third parties such as you despite your lack of knowledge concerning the car’s provenance. You would consequently have no defence to an action in conversion brought by the legitimate owner and would have to make do with a personal claim against the (often disappeared) thief. Similarly, if you as the owner of an estate in land grant a legal easement (see Chapter 8) to me, my interest will attach to the land and bind whosoever purchases the estate from you irrespective of whether they knew about this interest burdening their estate (subject to the rules about registration we consider in Chapter 15). This might have very serious consequences for the purchaser if my easement is incompatible with the purpose for which he bought the estate in the first place.

We will consider elsewhere the various means by which these potential difficulties might be surmounted (see Chapters 14 and 15 below). However, it is necessary here to note that the traditional approach of property law to the problem (both in this jurisdiction and beyond – see Extract 9.2 below) has been to limit the number of different types of property interest that might exist. This is often referred to by the shorthand term numerus clausus which, literally translated, means ‘finite number’, in recognition of the limited list of property interests known to the law. Third parties are, in this way, protected from being surprised by novel interests that they could not possibly have foreseen. We will consider the legitimacy of this approach in section 9.4 below, but must now content ourselves with noting that the courts and legislature have, in the face of these concerns, taken an extremely cautious approach to the recognition of new property interests.

Thus a right holder’s interest will not be accorded the status of a property right if the interest can be adequately protected without making the interest binding on third parties. For example, in Hill v. Tupper (1863) 2 H&C 121; 159 ER 51 (see Extract 5.1 above), the owners of a canal entered into a contract with Hill granting him the ‘exclusive right’ to hire out boats on the canal. However, Tupper, a local publican, was allegedly hiring out boats on the same stretch of canal, and Hill consequently sued him for infringing his ‘exclusive right’ to do so. The court unanimously held that Hill’s exclusive right to hire was simply a contractual right between him and the owner of the canal which consequently gave him no rights against third parties such as Tupper. In contrast, the owner of the canal (who by definition did have a property interest in it) could prevent third parties such as Tupper trespassing onto the canal and in failing to do so breached his contract with Hill, who could sue him accordingly. Thus Hill’s interest could be adequately protected without the need to turn the ‘right to ply for hire’ into a new property interest in land.

9.1.3.The requirements of property

Before an interest can be accorded proprietary status, it must fulfil certain conditions. If it lacks certainty, potential transferees of the interest will be reluctant to assume it, as they will not know what they are getting. More importantly, potential