Lloyd's Maritime and Commercial Law Quarterly
Book Reviews
UNJUST ENRICHMENT. Peter Birks, QC, DCL, FBA, Regius Professor of Civil Law, Fellow of All Souls College, Oxford. Oxford University Press, Oxford (2003) xxx and 268 pp, plus 6 pp Index. Paperback £25
.
Unjust Enrichment
recants much of An Introduction to the Law of Restitution
(1985), the work that firmly entrenched Professor Birks as the top of the table some 20 years ago. It is, in that respect, a remarkable book. One struggles to identify another scholar of similar stature so dramatically shifting direction. In the circumstances, the mere fact of change will generate a certain amount of consternation and condemnation. Birks’ new beliefs will prove unsettling for many who subscribed to his earlier views, especially those who substantially took matters on faith. Critics, in contrast, will be delighted by the opportunity to characterize the revisions as admissions of error and perhaps evidence of an inherently flawed project. But, in truth, both reactions will miss the point. The academic objective is not doggedly to maintain arguments for the sake of consistency or reputation, but rather continually to question and investigate with the aim of better understanding one’s subject. And from that perspective, Unjust Enrichment
represents a refreshing refusal to rest on the past.
Of course, not everything in Unjust Enrichment
is new. Much has been carried over or merely lightly revised (eg, an incontrovertible benefit may be recognized if the defendant received a benefit from which he either has realized, or is reasonably likely to realize
, a financial gain) (p 50). And even among the more substantial departures from Introduction
, some will already be familiar to those working in the field. That certainly is true of the first and, depending upon the audience, perhaps also the second, of the three principal areas of renunciation that Birks identifies in the preface to Unjust Enrichment
: (1) multi-causality, (2) the claimant’s expense, and (3) the unjust element (p xiv).
It has been six years since Birks recanted the quadration thesis (“Misnomer,” in W. Cornish et al.
(eds), Restitution: Past, Present & Future
(1998) 1), by which he previously insisted that “restitution” and “unjust enrichment” cover precisely the same territory—he former being exclusively and invariably triggered by the latter. While Birks now interprets “unjust enrichment” narrowly in terms of the three-part cause of action that bears that name (with the result that Unjust Enrichment
does not address instances of “unjust enrichment by wrongdoing,” in which the defendant is required to give up a benefit acquired through breach of an obligation), he broadly defines “restitution” as any response that is measured by reference to the defendant’s gain. Restitution consequently is said to be “multi-causal” insofar as it may be prompted by any of the four species of causative events in Birks’ private law taxonomy: unjust enrichment, wrongs, consent and miscellaneous other. The merits of that approach have already been debated in detail (A. Burrows, “Quadrating Restitution and Unjust Enrichment: A Matter of Principle” [2000] Restitution L Rev 257; M. McInnes, “Restitution, Unjust Enrichment and the Perfect Quadration Thesis” [1999] Restitution L Rev 118).
Birks’ first renunciation is largely a matter of semantics and structure. His second has much greater capacity to effect substantive changes. Reflecting the orthodox belief of the time, Introduction
, 351–355, said that restitution for unjust enrichment (as opposed to “restitution,” or
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