Alethic undecidability and alethic indeterminacy

Abstract

The recent, short debate over the alethic undecidability of a Liar Sentence between Stephen Barker (Barker 2012, 2014) and Mark Jago (Jago 2016) is revisited. It is argued that Jago’s objections succeed in refuting Barker’s alethic undecidability solution to the Liar Paradox, but that, nevertheless, this approach may be revived as the alethic indeterminacy solution to the Liar Paradox. According to the alethic indeterminacy solution, there is genuine metaphysical indeterminacy as to whether a Liar Sentence bears an alethic property, whether truth or falsity. While the alethic indeterminacy solution is presented here, and some revenge cases are considered and addressed, the primary aim of this paper is to revive and defend this underexplored and auspicious approach to solving the Liar Paradox.