Abstract: This book examines and proposes a solution to the knowability paradox. The paradox derives from the proof that if all truths are knowable, then all truths are known, which was first published by Frederic Fitch in 1963. It identifies two problems created by Fitch’s proof: a perceived anti-realism and the paradox created by the proof. It is argued that although the two problems are related, a defence against the threat to anti-realism is no solution to the paradox. The neo-Russellian theory of quantification is considered the only acceptable solution to the paradox, since no other approach offers any hope of addressing the fundamental paradoxicality involved in asserting a lost logical distinction between actuality and possibility.

Keywords: knowability paradox, truth, Frederic Fitch, neo-Russellian theory of quantification, logic