The Logical Paradoxes - Ep. 2.1: The liar paradox

Item: The Logical Paradoxes - Ep. 2.1: The liar paradox
Rating: 4
Author: PostSingularity Institute

by Graham Priest

Humanities, Social Sciences & Thought Philosophy & Ethics QDTTopics in philosophy QDTLPhilosophy: logic

🎙 Graham Priest 👥 5K 📅 May 28, 2020 ⏱ 13 min 👁 446 📄 expert opinion 🧭 2026-08-17

Available in: English (current) Français

Keywords

liar paradoxdialetheismself-referencetruthcontradiction

Summary

In this episode, Graham Priest discusses the liar paradox as a key argument for dialetheism, the view that some contradictions are true. He explains that the paradox arises from a sentence that asserts its own falsity, leading to a contradiction if it is true or false. Priest argues that after 2,500 years of discussion, no consensus exists on solving the paradox, and he suggests that the paradox may be a genuine argument for a true contradiction. He distinguishes between semantic and set-theoretic paradoxes, noting the historical context from ancient Greece to modern mathematics. The conversation is part of a series on contradiction, with Priest defending dialetheism against traditional objections. He emphasizes that the paradox is not a mere puzzle but a serious logical issue central to understanding truth. The discussion is introductory but assumes some familiarity with philosophical logic.

139 words

Critical Evaluation

Value of the Information & Strength of the Argument

The video provides valuable insights into the liar paradox and its role in dialetheism. Priest’s argumentation is clear and well-structured, presenting the paradox and its implications without oversimplifying. He effectively explains why the paradox remains unresolved and why dialetheism offers a plausible solution. The discussion is grounded in historical and contemporary logical research, making it a solid introduction to the topic.

70 words

Title / Content Match

The title accurately reflects the content, which focuses on the liar paradox as an example of logical paradoxes.

Quality & Reliability

8/10

The video features Graham Priest, a leading logician and philosopher, discussing the liar paradox and dialetheism. The content is well-structured and grounded in historical and contemporary logical research, but it is primarily an expert opinion rather than a peer-reviewed study.

Key Moments

Markers derived by PSI from the transcript: the creator did not define chapters.

Cited Sources

Complete playlist: The Logical Paradoxes — The playlist containing this episode and related discussions.

Concurring Sources

Stanford Encyclopedia of Philosophy: Dialetheism — Supports the view that dialetheism is a serious philosophical position.

Contribution & Novelties

This video offers a concise and accessible introduction to the liar paradox and dialetheism, presented by a leading expert. It clarifies the paradox’s structure and its historical significance, making it a valuable resource for students and enthusiasts. The discussion highlights the lack of consensus and presents dialetheism as a viable solution.

Pour aller plus loin :

Liar paradox - Wikipedia — Provides a comprehensive overview of the paradox and its history.
Dialetheism - Stanford Encyclopedia of Philosophy — An authoritative entry on dialetheism, including arguments and objections.
Graham Priest - Wikipedia — Background on the philosopher and his contributions to logic.

101 words

Radar Profile

The radar profile shows high scores in quality and reliability, with moderate scores in quantity and technical level, indicating a focused and expert-driven discussion rather than a broad overview.

Reliability 8/10