A Romalpa clause provides that, even after delivery, the seller retains title to goods agreed to be sold, until payment of the price of those goods or, in many cases, until payment of all sums due to the seller from the buyer. Its object is that, should payment not eventuate, the goods, though in the buyer's possession, are still the seller's property and available for resale by him. In the Scottish appeal of Armour v. Thyssen Edelstahlwerke A. G.1 the House of Lords encountered this example of a Romalpa clause:

It has long been established that the (involuntary) alienation which occurs when a bankrupt's estate vests in his trustee severs any beneficial joint tenancy, with the effect that the trustee holds the co-owned property as a beneficial tenant in common.1 The timing of such severance is of vital interest to unsecured creditors and the other coowners alike. If a beneficial joint tenant dies before severance is deemed to have taken place, his unsecured creditors are unable to claim against any share of the property, for it is an essential characteristic of joint tenancy that each joint tenant is entitled to the whole interest or estate, but only for his lifetime: upon the death of a joint tenant, his potential “share” accrues to those remaining in accordance with the right of survivorship. If, however, a co-owner dies after his interest has been severed, his share of the property is available for distribution among his creditors. Where a jointly-owned home is the debtor's only substantial asset, the distinction is crucial.

It is a commonplace that statements of legal doctrine sound both more determinate and more authoritative than they necessarily are. And this must be especially true of the maxims of equity,1 which possess a peculiarly Delphic quality, wrapped as they are in metaphor, grandly unqualified, and acknowledging no authority but transcendent wisdom. Therein may have lain their particular usefulness to the law.2 But therein too lies a worry. For it follows that reasoning based on a maxim especially facilitates the introduction of unarticulated valuejudgments; and indeed that such reasoning carries an unusually high risk of actual error, as the judges themselves miss their way.

The issue of miscarriages of justice1 has been at the heart of much recent discourse—legal, political and social—concerning the English criminal justice system. Indeed the crisis of confidence in the system has prompted attempts to re-establish legitimacy, which include such tried and tested methods as changes of personnel,2 and the appointment of a wide-ranging Royal Commission 3 which followed the attempt to quell the disquiet by the more focused May Inquiry.4 Much of the concern has arisen from the conduct of terrorist trials in Britain in the mid-1970s, the most important and significant 5 of which for the purposes of this paper were the trials of groups of terrorist suspects commonly known as the Birmingham 6,6

This article examines a variety of legal systems with a view to assessing the role currently played within each of them by the principle of unjust enrichment. By focusing on the characteristic features of unjust enrichment claims it seeks to demonstrate that, although there are significant differences between the ways in which different countries handle such claims, there is also much that those systems have in common. While under the common law the principle of unjust enrichment has endured a long struggle for recognition, in civil law systems it has been acknowledged for centuries. This may be because in civil law countries the principle has been expected to play only a residual, and therefore non-threatening, role in the law of obligations while in common law countries it has been called upon, if at all, to serve as the basis for the whole of the law of restitution. We should not assume, however, that all common law systems share one set of characteristics while all civil law systems share another. In some respects there is more in common between systems drawn from each category than there is between systems drawn from the same category. Mixed legal systems, as one might expect, tend to display characteristics drawn from both.