Kasher self-edits

In "Conversational Maxims and Rationality", Kasher, in his "Implicature", argues
that the relation between the Cooperative Principle and
the maxims of conversation is problematic (generally the
participants in a conversation do not have a mutual
purpose). He suggests replacing Grice's Cooperative
Principle with a rationality principal (achieving ends
with the most efficient means at the lowest costs).
Kasher argues that the maxims follow from this principle.