Mathematical Pluralism (Elements in the Philosophy of Mathematics), Cambridge University Press, 2024.

Mathematical pluralism is the view that there is an irreducible plurality of pure mathematical structures, each with their own internal logics; and that qua pure mathematical structures they are all equally legitimate. Mathematical pluralism is a relatively new position on the philosophical landscape. This Element provides an introduction to the position.




Everything and Nothing  (with Markus Gabriel), Polity, 2022.

Is it possible for reality as a whole to be part of itself?  Can the world appear within itself without thereby undermining the consistency of our thought and knowledge-claims concerning more local matters of fact?

This is a question on which Markus Gabriel and Graham Priest disagree. Gabriel argues that the world cannot exist precisely because it is understood to be an absolutely totality. Priest responds by developing a special form of mereology according to which reality is a single all-encompassing whole, everything, which counts itself among its denizens.  Their disagreement results in a debate about everything and nothing: Gabriel argues that we experience nothingness once we overcome our urge to contain reality in an all-encompassing thought, whereas Priest develops an account of nothing according to which it is the ground of absolutely everything.

A debate about everything and nothing, but also a reflection on the very possibility of metaphysics.


Explorer les contradictions, Les éditions Hermann, 2022.

Le principe de non-contradiction est un axiome logique fondamental, que les logiciens classiques ont érigé en loi de la pensée. Quelques paradoxes, comme ceux de l’autoréférence, suggèrent cependant que certaines contradictions seraient réelles. En travaillant sur ces énoncés incohérents ou contradictoires, les logiques paraconsistantes démontrent qu’il est parfois rationnel d’être incohérent. Et qu’il existe des énoncés qui ne sont ni-vrais-ni-faux ou d’autres qui sont à la fois vrais-et-faux. Jusqu’à quel point, dès lors, la cohérence peut-elle encore servir de critère à la vérité ?

Réunissant quelques textes phares de Graham Priest, l’une des têtes de file du mouvement paraconsistant moderne, le présent livre introduit le lectorat français aux problématiques soulevées par la paraconsistance et par la philosophie d’un des plus grands penseurs de ces cinquante dernières années.

Capitalism – its Nature and its Replacement: Buddhist and Marxist Insights, Routledge, 2022.

In this third decade of the 21st century, deep problems plague our world. Many people lack adequate nutrition, health care, and education, because–while there is enough wealth for everyone to meet these basic needs–most of it is tightly controlled by precious few. Global warming causes droughts, floods, rising sea levels, and soon the forced migrations of millions of people. In this book, philosopher Graham Priest explains why we find ourselves in this situation, defines the nature of the problems we face, and explains how we might solve and move beyond our current state. The first part of this book draws on Buddhist philosophy, Marx’s analysis of capitalism, and their complementary role in explaining our present crisis and the events that led us here. In the second part of the book, Priest turns to the much harder question of how one might go about creating a more rational and humane world. Here, he draws again on Buddhist and Marxist ideas as well as some key aspects of anarchist thought. His discussion of the need for bottom-up control of production, power, ideology, and an emerging awareness of our interdependence is a must-read for anyone who cares about the future of the planet and our latent capacity to care for each other.

What Can’t be Said: Paradox and Contradiction in East Asian Thought, Oxford University Press, 2021.

Typically, in the Western philosophical tradition, the presence of paradox and contradictions is taken to signal the failure or refutation of a theory or line of thinking. This aversion to paradox rests on the commitment-whether implicit or explicit-to the view that reality must be consistent.

In What Can’t be Said, Yasuo Deguchi, Jay L. Garfield, Graham Priest, and Robert H. Sharf extend their earlier arguments that the discovery of paradox and contradiction can deepen rather than disprove a philosophical position, and confirm these ideas in the context of East Asian philosophy. They claim that, unlike most Western philosophers, many East Asian philosophers embraced paradox, and provide textual evidence for this claim. Examining two classical Daoist texts, the Daodejing and the Zhaungzi, as well as the trajectory of Buddhism in East Asia, including works from the Sanlun, Tiantai, Chan, and Zen traditions and culminating with the Kyoto school of philosophy, they argue that these philosophers’ commitment to paradox reflects an understanding of reality as inherently paradoxical, revealing significant philosophical insights.

The Fifth Corner of Four: an Essay on Buddhist Metaphysics and the Catuṣkoṭi, Oxford University Press, 2018.

Graham Priest presents an exploration of Buddhist metaphysics, drawing on texts which include those of Nāgārjuna and Dōgen. The development of Buddhist metaphysics is viewed through the lens of the catuṣkoṭi. At its simplest, and as it appears in the earliest texts, this is a logical/metaphysical principle which says that every claim is true, false, both, or neither; but the principle itself evolves, assuming new forms, as the metaphysics develops. An important step in the evolution incorporates ineffability. Such things make no sense from the perspective of a logic which endorses the principles of excluded middle and non-contradiction, which are standard fare in Western logic. However, the book shows how one can make sense of them by applying the techniques of contemporary non-classical logic, such as those of First Degree Entailment, and Plurivalent Logic. An important issue that emerges as the book develops is the notion of non-duality and its transcendence. This allows many of the threads of the book to be drawn together at its end. All matters are explained, in as far as possible, in a way that is accessible to those with no knowledge of Buddhist philosophy or contemporary non-classical logic.

Logic: a Very Short Introduction, Second (extended) edition, Oxford University Press 2017. (First edition, University Press, 2000.)

9780192893208_450Logic is often perceived as having little to do with the rest of philosophy, and even less to do with real life. In this lively and accessible introduction, Graham Priest shows how wrong this conception is. He explores the philosophical roots of the subject, explaining how modern formal logic deals with issues ranging from the existence of God and the reality of time to paradoxes of probability and decision theory. Along the way, the basics of formal logic are explained in simple, non-technical terms, showing that logic is a powerful and exciting part of modern philosophy.

Translated into Portuguese as Lógica para Começar, Temas & Debates, 2002. Translated into Spanish as Una Brevísima Introducción a la Lógica, Oceano, 2006. Translated into Czech, as Logica, Dokorán, 2007. Translated into Japanese, Iwanami Shoten, 2008. Translated into Chinese by Yilan Press, 2011. Translated in Farsi, Press?, 2007. Translated into Italian, Condice Edizioni, 2012. Translated into Turkish as Mantik, Dost Kitabevi, 2017.  Translated into Finnish, as Logiikka,  Niin & Näin, 2017.

Towards Non-Being, 2nd (extended) edition. Oxford University Press, 2016. (First edition, Oxford University Press, 2005.)

Towards Non-BeinTOWARDS NON-BEINGg presents an account of the semantics of intentional language–verbs such as ‘believes’, ‘fears’, ‘seeks’, ‘imagines’. Graham Priest tackles problems concerning intentional states which are often brushed under the carpet in discussions of intentionality, such as their failure to be closed under deducibility. Priest’s account draws on the work of the late Richard Routley (Sylvan), and proceeds in terms of objects that may be either existent or non-existent, at worlds that may be either possible or impossible. Since Russell, non-existent objects have had a bad press in Western philosophy; Priest mounts a full-scale defence. In the process, he offers an account of both fictional and mathematical objects as non-existent. The book will be of central interest to anyone who is concerned with intentionality in the philosophy of mind or philosophy of language, the metaphysics of existence and identity, the philosophy or fiction, the philosophy of mathematics, or cognitive representation in AI.

This updated second edition adds ten new chapters to the original eight. These further develop the ideas of the first edition, reply to critics, and explore new areas of relevance. New topics covered include: conceivability, realism/antirealism concerning non-existent objects, self-deception, and the verb to be.

One: Being an Investigation into the Unity of Reality and of its Parts, including the Singular Object which is Nothingness. Oxford University Press, 2014.


An original exploration of philosophical questions concerning the one and the many. Priest covers a wide range of issues in metaphysics—including unity, identity, grounding, mereology, universals, being, intentionality, and nothingness—and deploys the techniques of paraconsistent logic in order to offer a radically new treatment of unity. Priest brings together traditions of Western and Asian thought that are usually kept separate in academic philosophy: he draws on ideas from Plato, Heidegger, and Nagarjuna, among other philosophers.

Logic. Sterling [Nook Book], 2010

9781402782138_p0_v1_s260x420Logic is often perceived as having little to do with the rest of philosophy, and even less to do with real life. In this engaging and accessible introduction, Graham Priest shows how wrong that conception is. He explores the philosophical roots of the subject, explaining how modern formal logic deals with issues ranging from the existence of God and the reality of time to paradoxes of probability and decision theory. Along the way, Priest lays out the basics of formal logic in simple, nontechnical terms.

[Note that this is an illustrated version of Logic: a Very Short Introduction.]

An Introduction to Non-Classical Logic: From If to Is. Cambridge University Press, Second Edition, 2008.

9780521670265This revised and considerably expanded Second Edition edition brings together a wide range of topics, including modal, tense, conditional, intuitionist, many-valued, paraconsistent, relevant, and fuzzy logics.

Part 1, on propositional logic, is the old Introduction, but contains much new material.
Part 2 is entirely new, and covers quantification and identity for all the logics in Part 1.

The material is unified by the underlying theme of world semantics. All of the topics are explained clearly using devices such as tableau proofs, and their relation to current philosophical issues and debates are discussed.

Students with a basic understanding of classical logic will find this book an invaluable introduction to an area that has become of central importance in both logic and philosophy. It will also interest people working in mathematics and computer science who wish to know about the area.

Part 1 was published as Introduction to Non-Classical Logic by CUP in 2001, and has been translated into German as Einführung in die nicht-klassische Logik, Mentis, 2008.

Doubt Truth to be a Liar. Oxford University Press, 2006.

9780199263288Dialetheism is the view that some contradictions are true. This is a view which runs against orthodoxy in logic and metaphysics since Aristotle, and has implications for many of the core notions of philosophy.

Doubt Truth to Be a Liar explores these implications for truth, rationality, negation, and the nature of logic, and develops further the defense of dialetheism first mounted in Priest’s In Contradiction.

In Contradiction: A Study of the Transconsistent. Oxford University Press, Second (Extended) Edition, 2006. (First edition, Martinus Nijhoff, 1987.)

9780199263295_450This book advocates and defends the view that there are true contradictions (dialetheism), a view that has flown in the face of orthodoxy in Western philosophy since Aristotle’s time.

The book has been at the centre of the controversies surrounding dialetheism ever since the first edition was published in 1987. This text contains the second edition of the book. It expands upon the original in various ways, and also contains the author’s reflections on developments over the last two decades.

Beyond the Limits of Thought. Oxford University Press, Second (extended) Edition, 2002. (First edition published by Cambridge University Press, 1995.)


This is a philosophical investigation of the nature of the limits of thought. Drawing on recent developments in the field of logic, Graham Priest shows that the description of such limits leads to contradiction, and argues that these contradictions are in fact veridical.

Beginning with an analysis of the way in which these limits arise in pre-Kantian philosophy, Priest goes on to illustrate how the nature of these limits was theorised by Kant and Hegel. He offers new interpretations of Berkeley’s master argument for idealism and Kant on the antimonies. He explores the paradoxes of self reference, and provides a unified account of the structure of such paradoxes. The book concludes by tracing the theme of the limits of thought in modern philosophy of language, including discussions of the ideas of Wittgenstein and Derrida.

Translated into Romanian as Dincolo de limitele gândirri (trs. Dimitru Gheorghiu), Paralela 45, 2007. The first edition was published by Cambridge University Press in 1995.

On Paraconsistency (with R. Routley). Research Report #l3, Research School of Social Sciences, Australian National University l983.

logicmetaphysics_coverReprinted as the introductory chapters of Paraconsistent Logic, G. Priest, R. Routley and J.  Norman (eds.), Philosophia Verlag, 1989. Translated into Romanian as chapters in I. Lucica (ed.), Ex Falso Quodlibet: studii de logica paraconsistenta (in Romanian), Editura Technica, 2004.