This thesis examines a number of events which are usually understood to act as methods by which people might acquire a new title to a chattel. It analyses the rules of English law that govern the acquisition of title following: (1) the taking possession of a chattel; (2) the mixture of identical chattels; (3) the natural production of a chattel from another; and (4) the manufacture of a new chattel. Each of these problems received extensive attention in the key Roman texts, and are discussed in modern textbooks on personal property law. Nonetheless, there remains a great deal of uncertainty in relation to these events, both as a matter of the substantive rules of English law which govern them, and as a matter of the underlying justifications of those rules.

It is the primary aim of the thesis to remedy that uncertainty, by offering accounts of the law governing each of our four events. Those accounts begin by setting out the most accurate description of English law that can be offered. Where the law can be stated with precision, the thesis aims to offer the best justification of its rules that can be found. If it is demonstrated instead that the law is unclear, the thesis prescribes how the law should develop in future.

In Chapters 2 and 3, the event of taking possession is considered. It is argued that the rule that the first possessor of an unowned chattel becomes that chattel’s owner is best justified on the grounds that interference with the chattel by others may interfere with the goals that the possessor has adopted and intends to use the possessed chattel to pursue. Similar concerns suggest that the law has good reason to recognise the existence of a legal interest of the same content as that of an owner in the possessor of a chattel that is already owned by another. Alternative justifications of the law governing the event of taking possession that are prominent in the modern literature are shown to be unconvincing. In Chapters 4, 5 and 6, uncertainty is shown to exist in the rules of law that govern mixture, natural production and manufacture. In the case of the first of these events, it is unclear what kind of legal interest is created; in the case of the latter two events, it is unclear in whom the legal interest that the event creates vests. The thesis argues that a mixture ought to lead to co-ownership of the mixed chattels; that a natural production should lead to the newly created chattel falling into the same proprietary condition as the chattel from which it was produced; and that a newly manufactured chattel ought to be owned by its manufacturer. These prescriptions are made primarily by building upon the goals-based justification of the rules governing the taking of possession.