English law

(a) The basic options for the legal system

Unjustified enrichment is not a contextual category: it does not deal with one particular aspect of life, but tends to crop up in a broad variety of widely divergent circumstances.^[4557] An error made in the course of discharging a contract of sale may give rise to an unjustified enrichment claim, but so can the break-up of a "de facto" marriage or the unauthorized use of someone else's photograph in a TV commercial.

® Cf.. for example. BGHZ 40. 272 sqq.; BGHZ 68. 276 (2771; BGHZ 72. 246 (248 sq.1; BGHZ 82, 28 (30); cf. further Otto Muh], "Wandlungen im Bereicherungsrecht und die Rechtsprechung des Bundesgerichtshofs", in: De iustitia et iure, Festgabe für Ulrich von Liibtow (1980), pp. 547 sqq.

³³⁵ More recently, attempts to establish a uniform formula for all enrichment claims have been revived, but they have, so far, not had any influence on the courts; cf especially Christian-Michael Kaehler, Bereicherungsausglekh und Vindikation.

³⁵⁷ Cf. also Zweigert/Kotz/Weir, p. 208: "The layman can make nothing of the expression, and can hardly be blamed for it."

^5M Cf. Birks, Restitution, p. 20.

such an abstract level that it does not, in itself, lead to greater legal certainty either. Some form of typological fragmentation must therefore occur, certain structural refinements and conceptual tools have to be developed and a stable pattern of analysis be agreed upon, an indispensable harness preventing Pomponius' "natural justice" from running wild. Modern German law has, obviously, been following the latter of these two courses. Scores of legal writers are sternly marching on, with the heavy tread of German scholarship, through the enrichment forest:^{[4559] * * * * [4560] meticulously mapping the great trunk road 812, conscientiously exploring complex side-paths and penetrating with the most unrelenting scrupulousness the remotest corners of the dreaded third-party enrichment jungle. [4561] So elaborate are the discussions that one may well ask whether the matter has not been taken too far and whether the results of all the theoretical efforts are really worth the trouble.[4562]}

(b) Rearing the backward child

English law, on the other hand, traditionally presents an entirely different picture.^[4563] Bedevilled by historical accident and legalistic fiction,^[4564] the law of restitution^[4565] has remained something of a backward child of the legal family.³⁶⁵ An amorphous and somewhat muddled multitude of restitutionary remedies at law and in equity have come to be recognized over the centuries and are still entrenched in modern English law.³⁶⁶ "My Lords", as Lord Diplock stated emphatically in 1978,³⁶⁷

"there is no general doctrine of unjust enrichment recognised in English law.

It is, essentially, the fear of an indeterminate liability that motivates judicial pronouncements such as this. But there have also been courageous attempts to shake off the fetters of the past, to extricate the

'money had and received', 'money paid', 'quantum meruit', and 'quantum valebant'. Each of these counts had its own set of rules for determining whether recovery was allowable, and unless the plaintiff brought his or her action within one of them the action was bound to fail, except in the rare instance where a court of equity could step in to dojustice according to the particular circumstances of the case. A regrettable by-product of the employment of indebitatus assumpsit to remedy restitutionary claims was the importation of the 'implied contract' notion, whereby a claim could succeed only if the defendant could be said to have impliedly promised to grant it. This idea of a fictional contract impeded the development of the English law of restitution from the middle of the eighteenth century to the middle of the twentieth. It prevented plaintiffs from recovering against defendants when the contract between them was ultra vires, it barred actions against defendants who were too young or mentally imbalanced, and it restricted damages recoverable from a tortfeasor. Indeed, it could be said that the whole subject of quasi-contract, and of its modern manifestation, restitution, has suffered from its identification with the term 'contract' in much the same way as the subject of constructive trusts has been badly handicapped by its identification with the concept 'trust'."

For a detailed analysis of the development of implied assumpsit, see Simpson, History, pp. 489 sqq. On unjust enrichment and the concept of quasi-contract in English law, cf. Dawson, op. cit., note 119, pp.

³⁶¹ On the relationship between restitution and unjust enrichment, see Birks, Restitution, pp. 16 sqq. ("Restitution and unjust enrichment identify exactly the same area of law. The one term simply quadrates with the other"). Is there a historical link with the restitution doctrine of the Spanish scholastics of the late Middle Ages (possibly via Grotius and Viscount Stair)? Cf. the suggestion by Coing, p. 191; cf, also supra, note 320.

³⁶⁵ Birks, Restitution, pp.

³³⁵ For a comprehensive discussion, see Goff and Jones, Restitution, pp. 69 sqq.

³⁶⁷ Orakpo v. Manson Investments Ltd. [1978] AC 95 (HL) at 104. unjust enrichment principle from its "quasi-contractual" niche and to break through to a general enrichment action. Such attempts date back to Lord Mansfield's famous ruling in Moses v. Macferlan, according to which "the defendant, upon the circumstances of the case, is obliged by the ties of natural justice and equity" to render restitution.^[4566] More recently, Sir Robert Goff and Gareth Jones, in their leading textbook on the law of restitution, have expressed the view that the law "is now sufficiently mature for the courts to recognize a generalized right to restitution".^[4567] The "predominant principle", under which the restitu- tionary remedies have to be brought home, consists in their opinion of three elements: "firstly, that the defendant has been enriched by the receipt of a benefit; secondly, that he has been so enriched at the plaintiffs expense; and thirdly, that it would be unjust to allow him to retain the benefit."^[4568] Lord Denning must be mentioned as a further prominent protagonist of the unjustified enrichment doctrine in the judicial sphere,^[4569] and so must be, among the academic writers, Professor Birks of Oxford.^[4570] Generally speaking, the opinion appears to be gaining ground these days that the recognition of generalized principles of enrichment liability does not necessarily lead to anarchy, but is in fact the only way of sorting out the present mess.^[4571] Yet, there are also indications that it is not a general enrichment action which will mark the end of all endeavours to rationalize this branch of the law.

V.