The Cooperative Principle
A conversation "works" because the participants abide by certain rules and conventions.
H.P.Grice (1975) saw cooperation between the participants as the fundamental principle underlying conversation.
The Four Maxims
H.P.Grice developed his idea of the cooperative principle by identifying four specific maxims (rules or conventions) which he said participants in a conversation usually follow.
1. The Maxim of Quantity
In making a contribution to a conversation, you should say neither more nor less that is required.