Unger argues for the extreme skeptical view that, not only can nothing ever be known, but no one can ever have any reason at all for anything. A consequence of this is that we cannot ever have any emotions about anything: no one can ever be happy or sad about anything. Finally, in this reduction to absurdity of virtually all our supposed thought, he argues that no one can ever believe, or even say, that anything is the case.
Review
"Oxford University Press has done well to reissue Ignorance, Peter Unger's first book in epistemology. Unger follows the argument to great depth, wherever it may lead, and the reader who follows along will be amply rewarded, which shows how impressively fresh and relevant this work remains after all these years."--Ernest Sosa, Brown University and Rutgers University.
"A powerful and profoundly original skeptical challenge. What you have to know-but if Unger is right, you don't-about ignorance. Anyone serious about epistemology should read it."--Fred Dretske, emeritus, Stanford University.
"A profoundly rewarding work, this is one of the most important studies in epistemology of the last fifty years. It should be read by any serious student in that field."--John Hawthorne, Rutgers University.
"Ignorance is, in my opinion, the best book in epistemology to appear in the last thirty years. It would be good for epistemology if every graduate student entering the field read and studied this classic."--Keith DeRose, Yale University.
http://www.amazon.com/Ignorance-Scep.../dp/0198244177