An underlying assumption in most conversational exchanges seems to be that the participants are co-operating with each other. This principle, together with four maxims that we expect our c to obey, was first described by the philosopher Paul Grice. The co-operative principle is stated in the following way: "Make your conversational contribution such as is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged" (Grice, 1975: 45) Supporting this principle are four maxims, often called the "Gricean maxims