© 2019

Ultralogic as Universal?

The Sylvan Jungle - Volume 4

  • Zach Weber

Part of the Synthese Library book series (SYLI, volume 396)

Table of contents

  1. Front Matter
    Pages i-xxxii
  2. Richard Routley
    Pages 1-121
  3. Richard Routley
    Pages 123-133
  4. Richard Routley
    Pages 135-160
  5. Richard Routley
    Pages 161-183
  6. Back Matter
    Pages 195-205

About this book


Ultralogic as Universal? is a seminal text in non-classcial logic. Richard Routley (Sylvan) presents a hugely ambitious program: to use an 'ultramodal' logic as a universal key, which opens, if rightly operated, all locks. It provides a canon for reasoning in every situation, including illogical, inconsistent and paradoxical ones, realized or not, possible or not. A universal logic, Routley argues, enables us to go where no other logic—especially not classical logic—can.

Routley provides an expansive and singular vision of how a universal logic might one day solve major problems in set theory, arithmetic, linguistics, physics, and more. It circulated in typescript in the late 1970s before appearing as the Appendix to Exploring Meinong's Jungle and Beyond. With engaging, forceful prose, unsparing criticism of entrenched institutions, and many tantalizing proof sketches (is the Axiom of Choice a theorem of naive set theory?), Ultralogic? has had a major influence on the development of paraconsistent and relevant logic.

This new edition makes this work available for a modern audience, newly typeset and corrected, along with extensive notes, and new commentary essays.


Paraconsistent logic Dialetheism Inconsistent mathematics Relevant logic Foundations of mathematics Foundations of science

Authors and affiliations

  1. 1.(deceased)ToowoombaAustralia

Editors and affiliations

  • Zach Weber
    • 1
  1. 1.Department of PhilosophyUniversity of OtagoDunedinNew Zealand

About the editors

Richard Routley/Sylvan (1935-1996), a New Zealand born philosopher, who was a research fellow at the Australian National University at the time of his death, rose to prominence for his work in the development of Relevance Logic, Deep Ecology and a revised and improved Meinongian ontology known as “noneism.”  An iconoclastic figure in Australian philosophy, Routley/Sylvan’s legacy thrives in the views of students and colleagues worldwide.

Zach Weber is a senior lecturer in philosophy at the University of Otago. His work is on paraconsistent logic and its applications in mathematics and philosophy.

Bibliographic information