Full Idea
We cannot forsake all of our beliefs and start over again, because then we could not know how to start.
Gist of Idea
We can't start our beliefs from scratch, because we wouldn't know where to start
Source
J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.1)
Book Reference
Pollock,J.L./Cruz,J: 'Contemporary Theories of Knowledge (2nd)' [Rowman and Littlefield 1999], p.66
A Reaction
A point with which it is hard to disagree, but even Descartes agreed with it (Idea 3604). Presumably all your beliefs can take it in turn to be doubted, while others are held true, or you can whittle the beliefs which can't be abandoned down to a minimum.
Related Idea
Idea 3604 When rebuilding a house, one needs alternative lodgings [Descartes]