The Outer Limits of Reason

The Outer Limits of Reason

What Science, Mathematics, and Logic Cannot Tell Us

By Noson S. Yanofsky

An exploration of the scientific limits of knowledge that challenges our deep-seated beliefs about our universe, our rationality, and ourselves.

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An exploration of the scientific limits of knowledge that challenges our deep-seated beliefs about our universe, our rationality, and ourselves.

Many books explain what is known about the universe. This book investigates what cannot be known. Rather than exploring the amazing facts that science, mathematics, and reason have revealed to us, this work studies what science, mathematics, and reason tell us cannot be revealed. In The Outer Limits of Reason, Noson Yanofsky considers what cannot be predicted, described, or known, and what will never be understood. He discusses the limitations of computers, physics, logic, and our own thought processes.

Yanofsky describes simple tasks that would take computers trillions of centuries to complete and other problems that computers can never solve; perfectly formed English sentences that make no sense; different levels of infinity; the bizarre world of the quantum; the relevance of relativity theory; the causes of chaos theory; math problems that cannot be solved by normal means; and statements that are true but cannot be proven. He explains the limitations of our intuitions about the world—our ideas about space, time, and motion, and the complex relationship between the knower and the known.

Moving from the concrete to the abstract, from problems of everyday language to straightforward philosophical questions to the formalities of physics and mathematics, Yanofsky demonstrates a myriad of unsolvable problems and paradoxes. Exploring the various limitations of our knowledge, he shows that many of these limitations have a similar pattern and that by investigating these patterns, we can better understand the structure and limitations of reason itself. Yanofsky even attempts to look beyond the borders of reason to see what, if anything, is out there.


Out of Print ISBN: 9780262019354 424 pp. | 6 in x 9 in 118 b&w illus.


$19.95 T ISBN: 9780262529846 424 pp. | 6 in x 9 in 118 b&w illus.


  • Yanofsky takes on this mindboggling subject with confidence and impressive clarity. He eases the reader into the subject matter, ending each chapter with further readings. His book is a fascinating resource for anyone who seeks a better understanding of the world through the strangeness of its own limitations and a must-read for anyone studying information science.

    Publishers Weekly, (starred review)

  • Yanofsky provides an entertaining and informative whirlwind trip through limits on reason in language, formal logic, mathematics—and in science, the culmination of humankind's attempts to reason about the world.

    The New Scientist

  • In my view, Outer Limits is an extraordinary, and extraordinarily interesting, book. It is a cornucopia of mind-bending ideas.

    Raymond S. Nickerson


  • The scope of the material covered is so wide, and the writing so clear and intuitive, that all readers will learn something new and stimulating.

    Thomas Colin

    Leonardo Reviews


  • Yanofsky has brought together insights about quantum mechanics, logic, and mathematics under one rubric. Very few others could pull that off. This book has the potential to be a classic.

    Prakash Panangaden

    School of Computer Science, McGill University


  • Winner, 2013 American Publishers Award for Professional and Scholarly Excellence (PROSE Award) in Popular Science & Popular Mathematics, presented by the Professional and Scholarly Publishing Division of the Association of American Publishers