Philosophy Research Archives

Volume 5, 1979

Oliver A. Johnson
Pages 368-417

Ignorance and Irrationality
A Study in Contemporary Scepticism

The essay is an exposition and critical analysis of Peter Unger's book Ignorance: A Case for Scepticism (Oxford, 1975). In the introductory chapter my main object, in addition to defining terms, is to distinguish the two forms of scepticism Unger defends in Ignorance, which he calls, respectively, scepticism about knowledge and scepticism about rationality. Chapter II is devoted to an exposition, analysis, and evaluation of the latter and Chapter III of the former. In Chapter IV I consider a second-order argument that informs Unger's case throughout the book, his "ancestor language" hypothesis. In the final chapter I assess his scepticism as a whole and attempt to develop some of its implications concerning both the possibility and actuality of knowledge.