Full Idea
Grice particularly identified two maxims as guiding conversation: the maxim of 'quality' (that one should assert only what one believes to be true and justified), and of 'quantity' (one should not assert less than one can).
Gist of Idea
Key conversational maxims are 'quality' (assert truth) and 'quantity' (leave nothing out)
Source
report of H. Paul Grice (Presupposition and Conversational Implicature [1977]) by Stephen Read - Thinking About Logic Ch.3
Book Reference
Read,Stephen: 'Thinking About Logic' [OUP 1995], p.70
A Reaction
I think it would be very foolish to boldly embrace the second maxim when talking to strangers. If white lies are occasionally acceptable, then what is the status of the first 'maxim'? Is it a moral maxim?