Grice remembers

"someone hears a noise"  iff  "a (past) hearing of a nose is an elemnet in a t. t. s. which is a member of a series of t. t. s.'s such that every member of the series EITHER  would, given certain conditions, contain as al element a MEMORY of some EXPERIENCE which is an element in some previous member,  OR  contains as an element some experience a memory of which would, given certain conditions, occur as an element in some subsequent member;  there being no subject of members which is independent from all the rest."