“The doctrine ex turpi causa has made its way into the law as an extension of a moral principle. If it is misused, the principle suffers. Moreover, its misuse is a symptom of a disease of thought that debilitates the law and morals. This is the failure to recognize that there is a fundamental difference between the law that expresses a moral principle and the law that is only a social regulation. If only in the growth of English law that distinction had been maintained, much of the arbitrariness and the absurdities in the cases I have cited would have been avoided. There is a dictum of Lord Wright’s which may some day be used as a foundation for a change of heart. Speaking of the maxim ex turpi causa, he said: ‘In these days there are many statutory offences which are the subject of the criminal law and in that sense are crimes, but which would, it seems, afford no moral justification for a court to apply the maxim’.Beresford v. Royal Insurance (1937), 2 KB. at 220.” Patrick Devlin, The Enforcement of Morals 60 (1968).
ex turpi causa
ex turpi causa (eks t[schwa]r-pIkaw-z[schwa]). [Latin] From an immoral consideration. • This phrase, a shortened form of the maxim ex turpi causa non oritur actio (“from an immoral consideration an action does not arise”), expresses the principle that a party does not have a right to enforce performance of an agreement founded on a consideration that is contrary to the public interest. [Cases: Action 4; Contracts 138(1).C.J.S. Actions §§ 29–30; Contracts §§ 280–281, 283–284, 290, 292, 300.]