The character introduced by Hume (Enquiry Concerning the Principles of Morals, Sec. 9, Pt. 2), who observes the general rules of justice and honesty, but who takes advantage of exceptions that he can make when doing so benefits him. Many approaches to ethics require that there is something irrational about this behaviour and set out to show that it is akin to self-contradiction; Hume himself sensibly regards the character as simply odious.