A Scotsman put it very nicely a decade ago: see J.Thomson, Principle or Policy? The Judicial Development of the Law of Delict (2003) 56 Current Legal Problems 123, 125, correctly railing against “a jurisprudence not of rules but of reasons”.

Andrew

For what it is worth, I think the (only) justification for the illegality principle is that the law must be coherent. The law cannot say at the same time "X is criminal" and also "if you assert that you did X we will assist you by making an award in your favour." This leads to a formal rule, such as in Tinsley, which looks to see whether the claimant (or defendant) is seeking to rely upon his own illegality.

There are then a number of exceptions usually put in Latin (non in pari delicto, locus poenitentiae)), 

Lots of people dislike formalistic reasoning, they perceive it as 'legalistic'. So, many dislike cases turning on whether the presumption of resulting trust or the principle of advancement apply (eg the difference between Tinsley v Milligan and Tribe v Tribe). Clearly the substantive relative merits of the parties, and whether and if so how, the behaviour of people in the future will be altered is not taken into account on this approach.

I think formalism is a virtue not a vice. If nothing else, I am temperamentally averse to judges looking behind rules to the basket of policies they perceive as underlying them, weighing them up, and using their best guess as to what the best result should be.
________________________________________
From: Duncan Sheehan (LAW) [Duncan.Sheehan@uea.ac.uk]
Sent: 29 October 2014 17:23
To: Robert Stevens; ENRICHMENT@LISTS.MCGILL.CA
Subject: RE: Terpitude in the UK Supreme Court

Rob,

Yes, the result seems right.

That said, I happen to be lecturing Tinsley v Milligan on Friday and lest it be said that I'm not up to date - Lord Toulson's comments at para 64 are getting a mention. I am though in the habit of telling the students when I do the illegality lectures that I think Tinsley generally hopeless as a decision. Why is this a welcome reassertion then of Tinsley? What's so good about it?

Duncan

-----Original Message-----
From: Enrichment - Restitution & Unjust Enrichment Legal Issues
[mailto:ENRICHMENT@LISTS.MCGILL.CA] On Behalf Of Robert Stevens
Sent: Wednesday, October 29, 2014 2:41 PM
To: ENRICHMENT@LISTS.MCGILL.CA
Subject: Re: [RDG] Terpitude in the UK Supreme Court

1. The decision is clearly right.

2. It contains what is, in my view, a very welcome reassertion of the approach
in Tinsley v Milligan in reaction to some backsliding by the Court of Appeal that
had thrown the law into unprincipled uncertainty.

3. There is a bizarre failure to consider the fact that what was in issue was the
infringement of a *Canadian* patent.

So, the claimant brings a claim in London seeking to restrain the selling of a
product here as a violation of an English patent. An interlocutory injunction
was granted  with a cross undertaking to pay for losses caused.  When the
claim came to trial, it was held that the patent was invalid, and the claim is for
the lost sales in the interim.

Meanwhile, in separate proceedings in Canada, it was subsequently held
(after the conclusion of all the English proceedings) that there had been an
infringement of a Canadian patent by the defendants.

Does a claim in England based upon the undertaking to compensate for loss
fail for illegality because of the infringement of the Canadian patent?

Of course not.

Do we in England  give effect to the patent laws in every country in the world?
No.

The first question is one of private international law. If, say, the law of
Ruritania is that selling blue widgets in England is unlawful, do we recognise
that?

Not necessarily, no. That it is illegal according to Ruritanian law doesn't entail
that it is contrary to the *law* in England (*law* meaning all of English law,
including its choice of applicable law rules, not just its domestic law).

Do we give international effect to Canadian patent laws so as to render sales
in England unlawful (although violating no English patent)? Of course not, any
more than a Canadian court would or should give effect to an English patent
when it comes to the legality of sales in Ottawa. What connected these facts
to Canada? As far as I can see, the only connection was that one of the parties
was Canadian. Nice for them, but not enough to apply Canadian law to the
issue before an English court.

4. I am not entirely sure that something like the illegality principle never
applies to private law wrongs. So, if a defendant commits two breaches of
contract, I don't think he can resist a claim for damages based upon one of
them by arguing "but I also committed another breach, you could have
terminated for that one, so your damages are lower"  Kwei Tek Chao v British
Traders and Shippers Ltd [1954] 2 QB 459 (Devlin J). Or, more controversially, if
I repeatedly trespass on your land in the face of your protests, if you
subsequently failed to remove a danger on the land could I argue "you could
foresee my presence because you knew I was in the habit of trespassing, and
so should have taken steps to protect me."

5. On a wholly unrelated point, those who have not seen this letter from the
Chief Justice of the HCofA complaining about the unsolicited submission of
articles by academics may find this interesting.

http://www.scribd.com/doc/244558945/French-CJ-letter-to-law-deans


Rob

________________________________________
From: Gerard Sadlier [gerard.sadlier@gmail.com]
Sent: 29 October 2014 12:13
To: obligations@uwo.ca
Cc: ENRICHMENT@LISTS.MCGILL.CA
Subject: Terpitude in the UK Supreme Court

The UK Supreme Court today gave judgment in Les Laboratoires Servier &
Anor v Apotex Inc & Ors [2014] UKSC 55.

http://www.bailii.org/uk/cases/UKSC/2014/55.html

On a first skim reading of the decision, I am sure the result is right
- less so whether the distinction apparently drawn by the majority
between breaches of the public law of a state, which give rise to the
illegality defence  and private rights (patent rights in this case)
which do not is entirely convincing. I think the patent rights at
issue in the case themselves high-light that the sharp distinction
between public law and private rights which the Court appears to
envisage may not always be an easy one to draw.

Kind regards

Ger

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 of unjust enrichment. To subscribe, send "subscribe enrichment" in
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 send "signoff enrichment" to the same address. To make a posting to
 all group members, send to <enrichment@lists.mcgill.ca>. The list is
 run by Lionel Smith of McGill University, <lionel.smith@mcgill.ca>.

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This message was delivered through the Restitution Discussion Group, an international internet LISTSERV devoted to all aspects of the law of unjust enrichment. To subscribe, send "subscribe enrichment" in the body of a message to <listserv@lists.mcgill.ca>. To unsubscribe, send "signoff enrichment" to the same address. To make a posting to all group members, send to <enrichment@lists.mcgill.ca>. The list is run by Lionel Smith of McGill University, <lionel.smith@mcgill.ca>.