Full Idea
We are like sailors who must rebuild their ship out on the open sea, never able to dismantle it in a dry-dock and reconstruct it there out of the best materials.
Gist of Idea
We must always rebuild our ship on the open sea; we can't reconstruct it properly in dry-dock
Source
Otto Neurath (Protocol Sentences [1932]), quoted by Alex Orenstein - W.V. Quine Ch.8
Book Reference
Orenstein,Alex: 'W.V. Quine' [Princeton 2002], p.177
A Reaction
This is the classic statement of the anti-foundationalist picture of knowledge. It is often quoted by Quine. A tricky issue. I have a lot of sympathy with Bonjour's rationalist foundationalism.