Priest on dialetheism: examination of some of his motivations and arguments

Hodjati, Seyyed Mohammad Ali; Farsian, Kasra

doi:10.30465/lsj.2019.5209

Priest on dialetheism: examination of some of his motivations and arguments

Document Type : Review

Authors

Seyyed Mohammad Ali Hodjati ¹

Kasra Farsian ²

¹ member of philosophy Dept.Tarbiat Modares University

² M.A. student in Dept. of Philosophy, Tarbiat Modares University

https://doi.org/10.30465/lsj.2019.5209

Abstract

Dialetheism is the view that some (and not all) contradictions are true. Since in classical logic the principle of impossibility of contradiction (the Law of Non-Contradiction, i.e., LNC) is widely accepted, the challenge between dialetheism and classical logic surely occurs. In this paper we have tried to explain the main problem of dialetheim and also examined Graham Priest’s arguments against LNC and his advocating to paraconsistent logic. Accordingly, Priest’s examples of dialetheic propositions in some systems such as Law, Natual and Formal Languages and Actual world are examined and criticized. The result is that if Priest’s argument be sound dialetheism may be acceptable.
Dialetheism is the view that some (and not all) contradictions are true. Since in classical logic the principle of impossibility of contradiction (the Law of Non-Contradiction, i.e., LNC) is widely accepted, the challenge between dialetheism and classical logic surely occurs. In this paper we have tried to explain the main problem of dialetheim and also examined Graham Priest’s arguments against LNC and his advocating to paraconsistent logic. Accordingly, Priest’s examples of dialetheic propositions in some systems such as Law, Natual and Formal Languages and Actual world are examined and criticized. The result is that if Priest’s argument be sound dialetheism may be acceptable.

Keywords

dialetheism

Priest

LNC

paraconsistent logic

Nabavi Lotfollah 1396 H.S). The Elements of Philosophical Logic. 2nd ed., Tarbiat Modares
University Press, 2010
Anderson, A, R, and Belnap, N, D. (1975). Entailment: the Logic of Relevance and Necessity.
Vol. 1. Princeton: Princeton University Press.
Gabbay, D, M, and Guenthner, F. (2007). Handbook o f Philosophical Logic. Vol. 14. (second
edition). Dordrecht: Springer press.
Priest, G (1979). «The Logic o f Paradox». Journal of Philosophical Logic 8, 219-241.
Priest, G (1984). «Semantic Closure». Studia Logica 43 (1), 117-129.
Priest, G (1998). «What is so bad about Contradictions». The Journal of Philosophy 95, 8, 410-
426.
Priest, G (2006).Tarski, A (1944). «The Semantic Conception of Truth and the Foundations of Semantics».
Philosophy and Phenomenological Research 4 (3), 341-376.
Tarski, A (1983). Logic, Semantics, Metamathematics : Papers from 1923 to 1938. (Second
Edition). J. Corcoran, ed.; J.H. W oodger, trans. Indianapolis: Flackett

In Contradiction. (Second Edition). New York: Oxford University Press.