He advocates that implied contract should be developed in all these respects to ensure that restitutionary justice is done by application of contractual principles where an element of the strict requirement for a contract is absent. Wrongs The traditional view of English law is that a wrong is a breach of a duty owed to "persons generally". For their part, civil lawyers see delicts as unlawful violations of general legal relations between persons. The major difference is the perspective from which such breaches/violations are analysed: duties broken by the wrongdoer for the common law, violated rights of the victim for the civil law.
This does not have a great impact on the topic under examination in this paper because both indicate some sort of wrongful behaviour categorised as a hazard for society. Yet, as we shall see, common lawyers tend to admit that breach of contract is a wrong. As has been said, although breach of contract cannot be considered to be of the same magnitude of wrongfulness as committing a tort or crime or even a breach of fiduciary duty, it is wrongful, as has been recognised for the purposes of economic duress. This illustrates the level of care which English lawyers take when qualifying breach of contract under the category "wrongs".
This suggests a distinction between different grades of wrongfulness which is taxonomically incorrect: breach of contract can be a wrong or not, but it cannot be "less" a wrong than other wrongs, tertium non datur. This kind of prudent approach is alien to civil lawyers, who found the exclusion of breach of contract from the law of delicts on the want of generality which characterises the breach in question: this does not engender the violation of a "social interest" because only a very specific group has an interest in the performance of the party in breach.
Hence, from the very beginning the contractual relationship affects only the parties to it, whereas a delict is an offence against the whole of society. Yet generality appears as a requirement in both the aforementioned definitions of wrongs and delicts; how can the outcome be so different? A plausible answer could be that the original meaning has been developed in English law up to a point at which its essence has changed. The requirement of generality has gradually disappeared from the basic definition which in its most recent form can be read thus: a wrong is the breach of a duty.
If "wrong" is defined as a breach of duty without any further qualification, its meaning is greatly enlarged: torts, equitable wrongs and breach of contract all find their cause in a breach of a duty, be it a duty owed to society, or to the other contracting party. A category of "wrongs" intended as breach of duty does not exist in civil law. This is why the question of the possible delictual character of a breach of contract, if raised, is dismissed in both of the civil law systems under comparison.
Thus, an analysis of restitution for delicts conducted from the perspective of, say, German law would ignore breach of contract. From the same perspective, an analysis of restitution for wrongs would hardly be conceivable, because German or Italian lawyers would consider "wrongs" to have the same meaning as "delict". Under this premise, a qualification of the topic as restitution for 'wrongs' appears to be most satisfactory from a comparative point of view and most precise as far as legal theory is concerned.
Conclusion To sum up, the claims by 'unjust enrichment' theorists that they have authority for their view contains elements of equivocation. There are many judges who speak of 'unjust enrichment', but much more is needed. Again, there are many academics, especially in the area of contracts, who are open to ideas of 'unjust enrichment' as a corrective to many of the problems of their disciplines; yet, very far from welcoming such writers as allies, they have been rebuffed.
Contract text writers who have added chapters on restitution have been brusquely told not to waste their time. And from the responses to the more innovative contractual theorists, it is clear that they are not welcome at all: 'unjust enrichment' theory asserts that there is a sharp line between liabilities voluntarily accepted and those involuntarily imposed, and so those who would bring unjust enrichment into contract are letting the side down by blurring this line.
So yet again, what looks like strong support for the 'unjust enrichment' approach seems to be unwelcome to the proponents of the theory. 'Restitution' is essentially a miscellaneous category, its various constituents united only by the fact that they have all been rejected from inclusion in other theories. Restitution consists of the left-overs of the law. Attempts to unite the material by reference to 'unjust enrichment' are therefore misguided. It does not follow, of course, that none of these left-overs is of any value.
What one set of theorists throws away, another may treasure: and such areas as subrogation and mistaken payments (to name but two) are, I believe, of considerable importance. Rather, the importance of 'restitution' is no more than the importance of its parts. Of course, it does not logically follow from the miscellaneous nature of restitution that there are no common themes, or underlying forms of order. Rather, there is no a priori reason to expect such order, and it would be rather surprising if it were present.
Arguments that there is some sort of order must be considered on their merits; but arguments that there must be some sort of order may be discounted. It is rather like the difference between a rubbish bin and a bottle bank. We might find order and value in either; it cannot be ruled out. But there is better reason to expect it in the latter. With the former, we know that those who put the stuff there thought it miscellaneous and valueless. They may have been wrong. But careful enquiry is needed.
Feeling themselves attacked on all sides, 'unjust enrichment' theorists have yet to give a very principled answer to any particular opposing point of view. There is a dim recognition that the 'restitution as miscellany' view is one which must be reckoned with. Yet no-one argues that restitution does or should include every residual form of liability (Birks 1985, p. 74), though the principle of selection is somewhat obscure. It is not for the 'miscellany' school to explain the 'point' of restitution, especially since they doubt whether there is one.
The existence of an academic subject called 'restitution' is a fact. But it is not for a school which doubts its bona fides to be told to explain its 'point'. What divides the two schools? They are united in believing that the topics conventionally regarded as within restitution have positive value, and amply merit the academic attention paid to them. They are united in their use of induction and generalisation as essential legal techniques. And they are agreed that talk of 'unjust enrichment' is a valuable part of legal and moral discourse. In an attempt to define how we differ, but some issues may be identified where the merits of 'unjust enrichment' approach, at least as currently practised, seem particularly in doubt.
1. Birks, "The Law of Unjust Enrichment: A Millennial Resolution",  Singapore JLS 318 2. Birks "Property and Unjust Enrichment: Categorical Truths"  NZLR 623 3. Birks, P. and Rose, F. (eds), (2000) Lessons of the swaps litigation (Oxford: Mansfield Press). 4. Birks, P. , (1985a) Introduction to the law of restitution (Oxford: Oxford University Press).