Full Idea
Foundationalists place the foundations of knowledge at a point where they are in principle accessible only to the individual knower. They cannot be 'shared' with another person, or with oneself at a later time.
Gist of Idea
Foundations seem utterly private, even from oneself at a later time
Source
Martin Kusch (Knowledge by Agreement [2002], Ch. 8)
Book Reference
Kusch,Martin: 'Knowledge by Agreement' [OUP 2004], p.99
A Reaction
Kusch is defending an extremely social view of knowledge. Being private to an individual may just he an unfortunate epistemological fact. Being unavailable even to one's later self seems a real problem for foundational certainty.