Full Idea
What is reality? Perhaps there isn't any such thing at all. It is but a working hypothesis which we try, our one desperate forlorn hope of knowing anything.
Gist of Idea
There may be no reality; it's just our one desperate hope of knowing anything
Source
Charles Sanders Peirce (Reasoning and the Logic of Things [1898], III)
Book Reference
Peirce,Charles Sanders: 'Reasoning and the Logic of Things', ed/tr. Ketner,K.L. [Harvard 1992], p.161
A Reaction
I'm not quite sure why the hope is 'forlorn'. We have no current reason to doubt that the hypothesis is working out extremely well. Lovely idea, though.