They are the maxims of quality, quantity, relevance and manner.
- Quality: speakers should be truthful. They should not say what they think is false, or make statements for which they have no evidence.
- Quantity: a contribution should be as informative as is required for the conversation to proceed. It should be neither too little, nor too much. (It is not clear how one can decide what quantity of information satisfies the maxim in a given case.)
- Relevance: speakers' contributions should relate clearly to the purpose of the exchange.
- Manner: speakers' contributions should be perspicuous: clear, orderly and brief, avoiding obscurity and ambiguity.