McGill Law Journal ~ Revue de droit de McGill
BOOK REVIEW
American Law Institute, Restatement of the Law Third: Restitution
and Unjust Enrichment, 2 vols (St Paul, Minn: American Law Insti-
tute, 2011), pp xxxvi, 670; pp xxxii, 745. ISBN 978-0-314-92962-4,
978-0-314-60468-2.
Lionel Smith *
The publication of the Restatement of the Law Third: Restitution and
Unjust Enrichment is an important accomplishment.1 Like all restate-
ments, it will have a significant influence on the development of the law,
within and without the United States. This particular restatement, more-
over, has the destiny of reviving a field that has long lain dormant in the
United States.
The subject of this restatement has a strange history in that country.
During the nineteenth century, the common law emerged from being a
science of pleading to a science of rights and obligations. Textbook writers
systematized much of it, often drawing on civilian learning. The common
law of unjust enrichment, however, resisted this trend, paradoxically be-
cause of the pleading history that should now have been left behind. Be-
fore the abolition of the forms of action, much of unjust enrichment was
pleaded through indebitatus assumpsit, which was also used to enforce a
great deal of what we would now call contract law. When the forms of ac-
tion were abolished, it was no longer necessary for lawyers to classify
grievances and claims in those outdated formal boxes.2 It was, however,
necessary for lawyers to classify them somehow. This is why it was so im-
* James McGill Professor of Law and Director, Quebec Research Centre of Private and
Comparative Law, Faculty of Law, McGill University. By way of disclosure, I note that I
am a member (elected 2007) of the American Law Institute and of the self-selecting
Members Consultative Group for the Restatement of the Law Third: Restitution and
Unjust Enrichment. I commented on some draft provisions and attended two meetings
at which drafts were discussed.
Lionel Smith 2012
Citation: (2012) 57:3 McGill LJ 629 ~ Rfrence : (2012) 57 : 3 RD McGill 629
1 Restatement (Third) of Restitution and Unjust Enrichment (2010) [R3RUE].
2 The classic account of this important stage in the history of the common law is FW
Maitland, Equity; Also the Forms of Action at Common Law: Two Courses of Lectures,
ed by AH Chaytor & WJ Whittaker (Cambridge: Cambridge University Press, 1929).
For a more concise version, see JH Baker, An Introduction to English Legal History, 4th
ed (London: Butterworths, 2002) ch 4 at 53ff.
630 (2012) 57:3 MCGILL LAW JOURNAL ~ REVUE DE DROIT DE MCGILL
portant that the great textbooks were written, to order and organize
thinking about the law of torts and the law of contracts. Through this sys-
tematizing period, the autonomy of unjust enrichment was ignored, and it
retained its old position as a kind of supplement to the law of contract,
even though obligations in unjust enrichment are imposed by operation of
law.
Andrew Kull, the reporter of the R3RUE, has shown the role played
by James Barr Ames in the process of reception into US common law of
the civilian idea of unjust enrichment, in the late nineteenth century.3
This set the stage for the first Restatement of Restitution, which played a
determinative part in the launch of restitution as an autonomous subject
of study in the common law world.4 Many other landmarks followed and
the subject is now thriving. Ironically, though, it nearly disappeared in
the United States. This may have been partly because of a general loss of
interest in the doctrinal study of law;5 although other basic fields such as
contracts, torts, and trusts did not have near-death experiences during
the twentieth century. In the 1980s, there was an effort to produce a Re-
statement Second of Restitution, but it was never finished.6 Andrew Kull
has suggested that as time passed US lawyers collectively forgot about
restitution.7
This is one of the reasons why the R3RUE is so important. It has the
didactic burden of re-educating US lawyers about one of the crucial parts
3 See Andrew Kull, James Barr Ames and the Early Modern History of Unjust Enrich-
ment (2005) 25:2 Oxford J Legal Stud 297. See also Lionel D Smith, The Province of
the Law of Restitution (1992) 71:4 Can Bar Rev 672 at 683.
4 Restatement of the Law of Restitution: Quasi Contracts and Constructive Trusts (1936).
Lord Wright, then Master of the Rolls, immediately wrote a lengthy review ((1937) 51:2
Harv L Rev 369) and referred to it in an article (Sinclair v. Brougham (1938) 6:3
Cambridge LJ 305 at 322-23). Lord Denning later claimed that he brought it to the at-
tention of the House of Lords in 1941: AT Denning, The Restatement of the Law: Its
Place in the English Courts (1951) 37 ABA J 329 at 330-31. I am grateful to Shawn
Comeau-Gallimore for this reference.
5 See John H Langbein, The Later History of Restitution in WR Cornish et al, eds,
Restitution: Past, Present and Future: Essays in Honour of Gareth Jones (Oxford: Hart,
1998) 57 at 61-62.
6 The only publications are Restatement (Second) of Restitution (Tentative Draft No 1,
1983); Restatement (Second) of Restitution (Tentative Draft No 2, 1984).
7 To put it bluntly, American lawyers today (judges and law professors included) do not
know what restitution is. The subject is no longer taught in law schools, and the lawyer
who lacks an introduction to its basic principles is unlikely to recognize them in prac-
tice. The technical competence of published opinions in straightforward restitution cas-
es has noticeably declined; judges and lawyers sometimes fail to grasp the rudiments of
the doctrine even when they know where to find it (Andrew Kull, Rationalizing
Restitution (1995) 83:5 Cal L Rev 1191 at 1195 [Kull, Restitution] [footnotes omit-
ted]).
BOOK REVIEW ~ RECENSION COMPARATIVE
631
of private law. It is carefully crafted to fulfill this role. Andrew Kull is the
leading scholar of the law of restitution in the United States and has been
working on this project since the 1990s. He deserves tremendous credit
for taking an enormous body of complicated law and turning it into a se-
ries of seventy sections of clearly restated law, which, with the supporting
notes, fill two substantial volumes. This is a mighty work, and the worthy
fruit of many long years of careful scholarly devotion.
What is a restatement, and how is it created? The American Law In-
stitute (ALI) was founded in 1923 for the improvement of the law. It
counts some three thousand members, most of whom are practicing law-
yers, but many of whom are judges and law professors. Most of the mem-
bers are based in the United States, but some of them are not. The re-
statements are not its only publications, but they are numerous and well-
known.8 In principle, the author of a restatement is the ALI itself, alt-
hough most of the work is done by the reporter of any particular restate-
ment. The basic structure of a restatement is a series of numbered propo-
sitions, not wholly unlike a code. The propositions are set in heavy type,
and in the vernacular of the ALI, they are called the black letter. To take
an example:
69. Notice
(1) As used in this Restatement, the expression without no-
tice means without notice of the facts giving rise to the restitution
claim against which a defense is potentially interposed.
the fact or has reason to know it.
(2) A person has notice of a fact if the person either knows
(a) the person has received an effective notification of
(3) A person has reason to know a fact if
the fact;
(b) knowledge of the fact is imputed to the person by
statute (including provisions for notice by filing or recording)
or by other law (including principles of agency); or
(c) other facts known to the person would make it rea-
sonable to infer the existence of the fact, or prudent to con-
duct further inquiry that would reveal it.
8 The first restatement published was that of contracts, in 1932. The first round of re-
statements later added agency, conflict of law, judgments, property, security, torts, and
trusts. The second round began in the 1950s and continued into the 1980s. The third
round began to appear in the 1990s and is ongoing. Besides the restatements, other ALI
projects include model laws, the most important of which is the Uniform Commercial
Code, and sets of principles of the law relating to certain fields.
632 (2012) 57:3 MCGILL LAW JOURNAL ~ REVUE DE DROIT DE MCGILL
Within each section, the black letter text is followed by explanatory
comments, some of which include illustrations (usually adapted from ac-
tual cases), and by a Reporters Note, which seeks to show the basis in
case law for the preceding black letter proposition. And here is a critical
point: in principle a restatement restates the law; it summarizes and clari-
fies the law. It is not a legislative project, and unlike a model law, it is not
intended to lead to legislation. But where there are multiple strands in
the case law, a restatement usually takes a position on what is the better
view; and in some cases, the view that it promotes may be a minority ra-
ther than a majority view.
In its relationship to the case law, then, a restatement is rather like a
textbook: it purports to explain the case law, and it binds no court in any
technical sense. Like a textbook, its authority rests on the persuasiveness
of its arguments, and perhaps on the authority of its author. And on this
point, it is important to notice that the process by which a restatement is
written is not at all like that for a textbook. The reporter generates draft
text (black letter and supporting commentary), called a preliminary
draft; this text is circulated for comment among a self-selecting group of
ALI members, namely the Members Consultative Group, which exists for
each pending restatement. This group may also be invited to a meeting to
discuss the draft. When it is ready, the draft, now designated a council
draft, is submitted to the Council of the ALI, a body of thirty senior
members. The council may require amendments or revision, but when it
has approved the text, it becomes a tentative draft. This draft is availa-
ble to all members and is presented and discussed at an annual meeting
of the ALI. This leads to one of the most striking features of the process,
which is that the whole membership of the ALI must approve this draft;
the black letter will be presented, section by section, to a room of hun-
dreds of lawyers, any one of whom has standing to intervene and raise
questions on anything from the substantive rule that is proposed to the
choice of words or punctuation in the draft.9 Not surprisingly, the produc-
tion of the whole document takes years, but the result is that when it is
complete, it has the authority that comes from the successful negotiation
of this complex procedure.
This is why the restatements are cited on a daily basis in US courts.
They are also influential elsewhere. Because they cover the common law
of the whole United States, and because they are worded (at least in the
black letter) in a relatively concise and accessible way, the restatements
are often the easiest way to determine, to the extent such a thing is possi-
9 In some cases, the council may approve the bringing of a discussion draft, rather than
a tentative draft, to the annual meeting. This is for discussion without formal approval
and adds another stage in the production.
BOOK REVIEW ~ RECENSION COMPARATIVE
633
ble, what the US law is. Another important point about the restatements
is that because they are restating case law, they speak the language of the
cases, and this is part of the reason that they are so often cited. They ana-
lyze the law in a doctrinal voice, which is a common voice throughout the
civil law and most of the common law world, but which has all but van-
ished from top-tier US law journals.
The R3RUE shares this tradition. It is also important to signal some
of its particular innovations. One of the most striking is in relation to
what is often called disgorgementthat is, the possibility of a remedy for
a wrongful act which is measured not by the plaintiffs loss but by the de-
fendants gain. In 3, which falls in the opening subdivision that states
general principles, it is simply provided: A person is not permitted to
profit by his own wrong. Although this kind of response is most closely
associated with fiduciary obligations, it is a possibility that has been ac-
cepted by the common law of torts for some time, and it seems to have re-
cently attracted new attention in Canada.10 The R3RUE provides, in
40-44, a strong affirmation of the principle that people should not be al-
lowed to profit by wrongdoing. More daringly, in 39, the R3RUE pro-
vides that a plaintiff can in some circumstances have disgorgement of the
profits of a breach of contract. This is still a relatively unexplored field in
Canadian law, but there are good arguments for allowing such claims.11
It was a noted feature and achievement of the first Restatement of Res-
titution, reflected in its title, to bring together as a single subject doctrines
that are derived from both the common law and equity. The R3RUE seeks
to perfect this, at least as far as possible, inasmuch as it rarely makes ref-
erence to the jurisdictional source of particular doctrines.12 In some cases
it goes even further; for example, the idea that a plaintiff must come to
court with clean hands is traditionally understood not only as sourced in
equity but as limited to equitable claims, in the sense that a plaintiff
bringing a claim in tort or breach of contract is not subjected to any in-
10 See e.g. Serhan (Trustee of) v Johnson & Johnson (2006), 85 OR (3d) 665, 269 DLR (4th)
279 (Div Ct), leave to appeal to SCC refused, 31762 (April 12, 2007); Serhan (Trustee of)
v Johnson & Johnson [Settlement Agreement], 2011 ONSC 128, 79 CCLT (3d) 272.
11 See Lionel D Smith, Disgorgement of the Profits of Breach of Contract: Property,
Contract and Efficient Breach (1994) 24:1 Can Bus LJ 121, which was adopted by the
House of Lords in allowing such a claim in AG v Blake, [2000] UKHL 45, [2001] 1 AC
268. In Canada, such a claim was allowed in Amertek Inc v Canadian Commercial Corp
(2003), 229 DLR (4th) 419 at para 467, 39 BLR (3d) 163 (Ont Sup Ct). On appeal, it was
held that the contract was not breached (Amertek Inc v Canadian Commercial Corp
(2005), 76 OR (3d) 241 at paras 133-35, 256 DLR (4th) 287 (CA)).
12 See Lionel Smith, Common Law and Equity in R3RUE (2011) 68:3 Wash & Lee L Rev
1185.
634 (2012) 57:3 MCGILL LAW JOURNAL ~ REVUE DE DROIT DE MCGILL
quiry as to his or her cleanliness. In 63, the R3RUE states the doctrine
as a general one, applicable to any claim for restitution.
63. Equitable Disqualification (Unclean Hands)
Recovery in restitution to which an innocent claimant would
be entitled may be limited or denied because of the claimants ineq-
uitable conduct in the transaction that is the source of the asserted
liability.
The overall approach inscribes itself firmly in the tradition of the re-
statements. The organization of the subject is largely by contextual cate-
gories. Groups of sections bear headings such as Transfers Subject to
Avoidance, Unrequested Intervention, and Restitution and Contract,
while individual sections include Mistaken Improvements, Mistake in
Gifts Inter Vivos, Duress, Judgment Subsequently Reversed or Avoid-
ed, and Illegality. Those who know the field will understand the state-
ment that the table of contents owes more to Goff and Jones13 or Mad-
daugh and McCamus14 than to the approach of Peter Birks15 or Andrew
Burrows.16 Birks sought analytical rigour and attempted to explain all of
the law of unjust enrichment according to a simple formula: the plaintiff
must show that the defendant was enriched, that the enrichment was at
the plaintiffs expense, and that there was some positive reason (mistake
or duress being examples) that the enrichment was unjust. Due to this
approach, he has had many followers. The formulation of the final ele-
ment in Canadian common law is that there must be no juristic reason
for the defendants enrichment and the corresponding deprivation of the
plaintiff. A lot of ink has been spilled on what this statement means, and
whether it is better or worse than the approach based on positive rea-
sons.17 Toward the end of his life, Birks himself changed his mind in fa-
vour of a version of the Canadian approach, describing this as a Dama-
scene conversion.18
13 Lord Goff of Chieveley & Gareth Jones, The Law of Restitution, 7th ed by Gareth Jones
(London, UK: Sweet & Maxwell, 2007).
14 Peter D Maddaugh & John D McCamus, The Law of Restitution, loose-leaf (consulted
on 25 January 2012), (Toronto: Canada Law Book, 2011).
15 Peter Birks, An Introduction to the Law of Restitution, revised ed (Oxford: Clarendon
Press, 1989); Peter Birks, Unjust Enrichment, 2d ed (Oxford: Oxford University Press,
2005) [Birks, Unjust Enrichment].
16 Andrew Burrows, The Law of Restitution, 3d ed (Oxford: Oxford University Press,
2011).
17 See e.g. Mitchell McInnes, Making Sense of Juristic Reasons: Unjust Enrichment After
Garland v. Consumers Gas (2004) 42:2 Alta L Rev 399; Lionel Smith, Demystifying
Juristic Reasons (2007) 45:2 Can Bus LJ 281.
18 Birks, Unjust Enrichment, supra note 15 at xii.
BOOK REVIEW ~ RECENSION COMPARATIVE
635
The R3RUE will have none of this approach. The opening proposition
in 1 states that [a] person who is unjustly enriched at the expense of
another is subject to liability in restitution. There is no general analytical
formula for the elements of a claim in unjust enrichment; there are only
the manifold, context-specific statements of liability conditions. Kull sets
out one such formula and makes his view plain: Formulas of this kind
are not helpful, and they can lead to serious errors. They lend a specious
precision to an analysis that may be simple or complicated but which at
any rate is not susceptible of this form of statement.19
This pragmatic approach runs through the whole work. Another ex-
ample relates to a subject already mentionedgain-based remedies for
wrongdoing. It is very difficult to understand how these can be seen as
cases of unjust enrichment, and most of the literature rejects such a view.
The plaintiffs claim is founded on the wrong; the claim does not get off
the ground without showing the wrong. But unjust enrichment is an au-
tonomous source of liability precisely because it does not require the plain-
tiff to show any wrongdoing. It does not depend on the breach or in-
fringement of a prior entitlement; if it did, it would itself be a tort. Thus,
the cases of gain-based remedies for wrongdoing are part of the law of
wrongs, including, perhaps, the wrong of breaching a contract. They raise
a purely remedial question as to whether the plaintiff should be allowed
to demand the defendants gain. In such a case, the elements of the not-
wrong of unjust enrichment are immaterial.20 Indeed, as noted above, it
is increasingly common to also reject the word restitution for cases of
gain-based remedies for wrongdoing; the plaintiff is not seeking a giving
back but a giving up of a gain that generally did not come from the plain-
tiff but from a third party. Hence the trend toward the word disgorge-
ment, which even the R3RUE adopts in this context.21 But even those
who reject this word tend to agree on the fundamental analytical distinc-
19 R3RUE, supra note 1, 1 cmt d.
20 The same facts may give rise to both kinds of liability, as where the plaintiff transfers
money to the defendant due to the defendants fraud; this example is both a tort and an
unjust enrichment. I am concerned with cases where the plaintiff is the victim of a
wrong but did not transfer wealth to the defendant.
21 The R3RUE frequently uses the word disgorgement to refer to gain-based remedies
for wrongdoing, and this even appears in the black letter of 51(4): The object of resti-
tution in such cases is to eliminate profit from wrongdoing while avoiding, so far as pos-
sible, the imposition of a penalty. Restitution remedies that pursue this object are often
called disgorgement or accounting. However, the term is not used in opposition to
restitution, to mean giving up rather than giving back. Rather, in the R3RUE it is
used as a subset of the wider idea of restitution. Restitution means any remedy that
takes away the defendants gain and disgorgement appears to refer to restitution in
those cases where the defendant has committed a wrong, even though these cases are
also considered cases of restitution for unjust enrichment in the R3RUE.
636 (2012) 57:3 MCGILL LAW JOURNAL ~ REVUE DE DROIT DE MCGILL
tion between restitution for wrongs, which does not depend on the cause
of action in unjust enrichment, and restitution for unjust enrichment,
which does so depend.22
The R3RUE will have none of this either. Kull, of course, is perfectly
aware of the debates but takes the view that they are irrelevant in practi-
cal terms. He notes that [n]othing practical turns on this disagreement
except the identification of the applicable period of limitations … . Ordi-
narily, a complaint that alleges profitable wrongdoing by the defendant
states a claim for restitution of unjust enrichment as well as a claim for
damages in tort.23 This argument is at least doubtful; many scholars (not
to mention the Supreme Court of Canada) believe that unjust enrichment
depends on an unjust transfer from plaintiff to defendant. Why should it?
In unjust enrichment, the defendant is being made liable without having
done anything wrong; this needs justification. The justification is that the
defendant is only being required to return some enrichment that, for some
reason or other, he should not have got. He is not, like a typical tort de-
fendant, being required to reach into his own pocket. It follows from this
distinction that in a case in which the defendant has committed a profita-
ble wrong, but the profit was not acquired from the plaintiff, there is no
unjust enrichment in the technical sense. This scenario includes the very
typical case in which the defendant misappropriates the plaintiffs proper-
ty and makes some profitable or expense-saving use of it. The only claim
is the claim based on the wrong.
The R3RUE does not view unjust enrichment as a body of law charac-
terized by liability without wrongdoing. It characterizes the law of restitu-
tion as the law of liability for gains:
Restitution is the law of nonconsensual and nonbargained bene-
fits in the same way that torts is the law of nonconsensual and
nonlicensed harms. Both subjects deal with the consequences of
transactions in which the parties have not specified for themselves
what the consequences of their interaction should be. The law of
torts identifies those circumstances in which a person is liable for in-
jury inflicted, measuring liability by the extent of the harm; the law
of restitution identifies those circumstances in which a person is lia-
22 See e.g. Peter BH Birks, A Letter to America: The New Restatement of Restitution,
online: (2003) 3:2 Global Jurist Frontiers 2
this text that sought unsuccessfully to influence the drafting of the R3RUE, Birks re-
jected the word disgorgement but continued to insist that restitution claims that are
based on wrongs cannot be understood as based on unjust enrichment. See also Douglas
Laycock, The Scope and Significance of Restitution (1989) 67 Tex L Rev 1277. Lay-
cock, the leading scholar of remedies in the US, was closely involved in the development
of the R3RUE. Kull set out his disagreement with Laycock on this point in Kull,
Restitution, supra note 7 at 1222-26.
23 R3RUE, supra note 1, 1 cmt e.
BOOK REVIEW ~ RECENSION COMPARATIVE
637
ble for benefits received, measuring liability by the extent of the
benefit.24
I would describe this characterization as a minority view, and one dif-
ficult to defend. The law of torts is not only concerned with harm and loss;
it is concerned with the infringement of rights. We know this because it
reacts to infringements of rights even if they do not lead to harm. This
particularity is why torts sometimes lead to nominal damages, to injunc-
tions, and to the disgorgement of wrongful gains. But this passage is im-
portant because it suggests that the basic organizational categories, resti-
tution and tort, are built on remedies, and not on causes of action or
sources of obligation. This difference is why, in the R3RUE, any case in-
volving a gain-based remedy is a case of restitution, and, it seems to fol-
low, any case of restitution is a case of unjust enrichment. The R3RUE
states that
there are significant instances of liability based on unjust enrich-
ment that do not involve the restoration of anything the claimant
previously possessed. The most notable examples are cases involving
the disgorgement of profits, or other benefits wrongfully obtained, in
excess of the plaintiffs loss. …
In short, most of the law of restitution might more helpfully be
called the law of unjust or unjustified enrichment. … When used in
this Restatement to refer to a theory of liability or a body of legal
doctrine, the terms restitution and unjust enrichment will gener-
ally be treated as synonymous.25
But liabilities need justification. Some arise from wrongdoing; those in
unjust enrichment do not. Where a defendant has made a gain that has
not come from the plaintiff, why should he give it to the plaintiff? He can
only be made to give it up if he has gained it by wronging the plaintiff.
Kulls approach seems to be that this scenario is a case in which the gain
24 Ibid, 1 cmt d.
25 Ibid, 1 cmt c. This suggests that there is some part of restitution that is not about un-
just enrichment, but it is not clear from this passage what that part might be. However,
the answer may lie in 38(2)(b). This deals with the case where a plaintiff performs his
part of a contract, or some of it, and then finds that the other party commits a breach of
contract that allows the plaintiff to treat the contract as discharged. The usual view is
that this plaintiff can sue for damages based on the value of the contract, or (perhaps
subject to some limitations) ignore the contract and sue in unjust enrichment for the
value of the enrichment conferred. Treating that second claim as one in unjust enrich-
ment means that it lines up conceptually with what would happen even if the contract
had been void or unenforceable, so that no claim for contract damages could possibly lie
(see e.g. Deglman v Guaranty Trust Co of Canada, [1954] SCR 725, [1954] 3 DLR 785).
The R3RUE, however, takes the view that in the case of the breached contract, the se-
cond claim is a contractual claim for a special measure of damages, not a claim in un-
just enrichment. See the introductory note before 37 and also 38, cmt a. The claim,
therefore, is classified as a claim for restitution arising from contract.
638 (2012) 57:3 MCGILL LAW JOURNAL ~ REVUE DE DROIT DE MCGILL
must be given up. As such, it is a case of liability in restitution, and thus a
case of unjust enrichment, and thus we can understand it as arising out-
side of the law of wrongs. But this seems to be lifting one up by ones boot-
straps; where does the liability come from if not from the wrong? At least,
Kulls approach is inconsistent with one that separates torts from unjust
enrichment by saying that the law of torts is about wrongs, while the law
of unjust enrichment does not depend upon wrongdoing. Kull, of course, is
perfectly aware that on his approach the majority of unjust enrichment
cases do not involve wrongdoing; but his categories make it impossible for
him to identify this as a defining feature of unjust enrichment, as the very
thing that separates it from the law of torts. And as we have seen, if one is
interested in unjust enrichment as an autonomous source of obligations,
one cannot define it as the law of restitution. That only ducks the definitional
or justificatory question of where obligations to make restitution come from.
Not that he minds. This, it seems, is exactly why he does not need an
analytical formula that will delineate the shape of liability in unjust en-
richment. The subject is defined and delineated by the availability of res-
titution. The availability of restitution is explored casuistically, via the
examination of a range of contextual factors that differ from situation to
situation. It is not the role of the R3RUE to develop a theory of unjust en-
richmentof why it exists and what are its precise boundariesbut ra-
ther to help lawyers and courts grapple with cases and to provide a set of
principles to guide them.26 Those who seek an overarching theory will not
find it here. This, after all, is a restatement. Its mission is to restate this
enormous body of law in a way that fits it together logically and accessi-
bly. Without any doubt, in this mission it succeeds.
26 In other words, Kull is not interested in theoretical debates except to the extent that
they have practical implications. We have already seen that in speaking of the question
whether a claim for a gain-based remedy for wrongdoing is a claim based on the wrong
or a claim in unjust enrichment, Kull writes, Nothing practical turns on this disagree-
ment except the identification of the applicable period of limitations (R3RUE, supra
note 1, 1 cmt e). One might also ask about rules relating to private international law,
and perhaps substantive defences such as change of position, which may also differ be-
tween causes of action. More broadly, it is in the situation of the brand new case, which
does not quite fit any previous category or which raises a novel permutation, that an
overall theory of unjust enrichment may be of great practical use. See e.g. the discus-
sion in Peel (Regional Municipality) v Canada, [1992] 3 SCR 762 at 789, 98 DLR (4th)
140, where McLachlin J. said, for the majority, [N]ew situations can arise which do not
fit into an established category of recovery but nevertheless merit recognition on the ba-
sis of the general rule. Although he was speaking of applied psychology, I believe that
Kurt Lewins observation also applies to law: [T]here is nothing so practical as a good
theory (Field Theory in Social Science: Selected Theoretical Papers (New York: Harper
& Row, 1951) at 169).
