Grice's "10 comm"

One unpublication by Grice reads: "ten commandments."

Surely the maxims in "Logic and conversation" are "9"

1. make your contribution as informative as is required (for the current purposes of the exchange)
2. do not make your contribution more informative than is required
3. do not say what you believe to be false
4. do not say that for which you lack adequate evidence
5. be relevant
6. avoid ambiguity
7. avoid obscurity of expression
8. be brief (avoid unnecessary prolixity) [sic]
9. be orderly

But in "Presupposition and conversational implicature" he adds

10. frame whatever you say in the form most suitable for any reply that would be regarded as appropriate, or facilitate in your form of expression the appropriate reply

That gives us Moses's table of ten commandments, which is what Grice's "10 comm" was all about!

Or not!

Part of the complication in the numbering is Grice's use of maxim, submaxim and supermaxim. But the maxims simpliciter as those listed above.

He uses 'supermaxim' a maxim under which maxim (3) and maxim (4) fall. He states it as "Try to make a make your contribution one that is true."

He also uses 'supermaxim' to comprise maxim (6), maxim (7), maxim (8), maxim (9) and indeed maxim (10). He states it as "Be perspicuous [sic]!"