Is Truth a Lie? Perspectives on the Semantic Paradoxes

Abstract

The article offers a short opinionated introduction to the semantic paradoxes and to some of the main competing theories about them. The article starts with clarifying the notion of semantic paradox and with providing a sketch of the history of the semantic paradoxes. After introducing the phenomenon of self-reference and the principles of truth exploited by the semantic paradoxes, the article proceeds to presenting in detail the most famous such paradox, the Liar paradox. With the Liar paradox on the table, the article classifies solutions to it according as to whether they revise our traditional conception of truth or our traditional conception of logic. As for solutions of the former kind, the article discusses in particular theories that replace the property of truth with a hierarchy of properties that partially resemble truth and theories that attribute truth to sentence tokens rather than sentence types. As for solutions of the latter kind, the article discusses in particular theories that reject the law of excluded middle, theories that reject the law of non-contradiction and theories that reject (what the article calls) the principle of persistence.

Key words: non-classical logics, Liar paradox, semantic paradoxes, truth.