“No court will lend its aid to a man who founds his cause of action on an immoral or an illegal act. If, from the plaintiff’s own stating or otherwise, the cause of action appears to arise ex turpi causa, or the transgression of a positive law of this country, there the court says that he has no right to be assisted. It is upon that ground the court goes; not for the sake of the defendant, but because they will not lend their aid to such a plaintiff. So if the plaintiff and defendant were to change sides, and the defendant was to bring his action against the plaintiff, the latter would then have the advantage of it; for where both are equally in fault, potior est condition defendentis.”
“The objection, that a contract is immoral or illegal as between plaintiff and defendant, sounds at all times very ill in the mouth of the defendant. It is not for his sake, however, that the objection is ever allowed; but it is founded in general principles of policy, which the defendant has the advantage of, contrary to the real justice, as between him and the plaintiff . . .”
“That principle has been applied again and again, for over 200 years. It is applicable in courts of equity as well as courts of law: see, e.g., the notes to Roberts v. Roberts (1818) Dan. 143, 150-151 and Ayerst v. Jenkins (1873) L.R. 16 Eq. 275, 283, per Lord Selborne L.C. In 1869 Mellor J. said that the maxim in pari delicto potior est conditio possidentis ‘is as thoroughly settled as any proposition of law can be:’ see Taylor v. Chester (1869) L.R. 4 Q.B. 309, 313. It is important to observe that, as Lord Mansfield made clear, the principle is not a principle of justice; it is a principle of policy, whose application is indiscriminate and so can lead to unfair consequences as between the parties to litigation. Moreover the principle allows no room for the exercise of any discretion by the court in favour of one party or the other.”
“These proposals, if enacted by Parliament, would introduce more flexibility into this area of the law (although without reintroducing a general public conscience discretion) . . . The present state of the law is as laid down by the majority of the House in Tinsley v Milligan[1994] 1 AC 340 . Any legislative change is likely to widen the test, not to narrow it.”
“To allow recovery in these cases would be to allow recovery for what is illegal. It would put the courts in the position of saying that the same conduct is both legal, in the sense of being capable of rectification by the court, and illegal. It would, in short, introduce an inconsistency in the law. It is particularly important in this context that we bear in mind that the law must aspire to be a unified institution, the parts of which - contract, tort, the criminal law - must be in essential harmony. For the courts to punish conduct with the one hand while rewarding it with the other, would be to create an intolerable fissure in the law’s conceptually seamless web…We thus see that the concern, put at its most fundamental, is with the integrity of the legal system.”
“Each case has to be considered on its merits. Nor must it be forgotten that the rule by which contracts not expressly forbidden by statute or declared to be void are in proper cases nullified for disobedience to a statute is a rule of public policy only, and public policy understood in a wider sense may at times be better served by refusing to nullify a bargain save on serious and sufficient grounds.”
“The maxim ex turpi causa expresses not so much a principle as a policy. Furthermore, that policy is not based upon a single justification but on a group of reasons, which vary in different situations.”
“The defence of illegality rests upon the foundation of public policy. ‘The principle of public policy is this…’ said Lord Mansfield by way of preface to his classic exposition of the defence in Holman v Johnson (1775) 1 Cowp 341, 343. ‘Rules which rest upon the foundation of public policy, not being rules which belong to the fixed or customary law, are capable, on proper occasion, of expansion or modification’: Maxim Nordenfelt Guns and Ammunition Co Nordenfelt[1893] 1 Ch 630 , 661 (Bowen LJ). So it is necessary, first, to ask “What is the aspect of public policy which founds the defence?” and, second, to ask ‘But is there another aspect of public policy to which application of the defence would run counter?’”