Full Idea
The possibility of making certain of what we already know suggests that knowing a proposition does not entail its being certain.
Gist of Idea
We can make certain of what we know, so knowing does not entail certainty
Source
Robert Audi (Epistemology: contemporary introduction [1998], VIII p.220)
Book Reference
Audi,Robert: 'Epistemology: a contemporary introduction' [Routledge 1998], p.220