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Shadows of the Mind: A Search for the Missing Science of Consciousness Hardcover – 1 Oct 1994

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Product details

  • Hardcover: 473 pages
  • Publisher: Oxford University Press; First UK EDITION edition (1 Oct 1994)
  • Language: English
  • ISBN-10: 0198539789
  • ISBN-13: 978-0198539780
  • Product Dimensions: 15 x 3.3 x 23 cm
  • Average Customer Review: 4.7 out of 5 stars  See all reviews (3 customer reviews)
  • Amazon Bestsellers Rank: 286,933 in Books (See Top 100 in Books)
  • See Complete Table of Contents

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About the Author

About the Author: Roger Penrose is the Rouse Ball Professor of Mathematics at the University of Oxford. He is the author of The Emperor's New Mind, which was a New York Times bestseller and was awarded the UK's 1990 COPUS Prize for science writing. In 1988, he received the internationally prestigious Wolf Prize for physics, shared with Stephen Hawking, for their joint contribution to our understanding of the universe.

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1 of 1 people found the following review helpful By Alan Rivière on 29 April 2013
Format: Hardcover
Shadows of The Mind by Sir Roger Penrose is a difficult read. It is not for everybody. It requires a strong background in mathematics and the physical sciences. The reward is a fascinating peek at the science of human consciousness.

This book is a follow-up of Sir Penrose's first book The Emperor's New Mind. It is divided into two parts. In Part I, using Gödel's incompleteness theorems as he did in his first book, Sir Penrose argues that the human mind, unlike an electronic computer, is non-algorithmic and hence non-computational. In plain English, artificial intelligence based on electronic computers is impossible, no matter how advanced computers become. His argument is terribly dry and mathematical. The point I took from Sir Penrose's argument here is that the human mind works in a way distinctly different from that of an electronic computer. His non-computational thesis is contrary to mainstream theories that the mind emerges from the brain as a result of complex computations at the synapses of the neurons.

The book becomes interesting in Part II, where Sir Penrose explains the "puzzle mysteries" and "paradox mysteries" as well as various aspects of quantum mechanics. But the most fascinating is his theory of how consciousness arises at the human brain, which he co-developed with Dr. Stuart Hameroff, an anesthesiologist and a professor at the University of Arizona. The theory is later called Orchestrated Objective Reduction or Orch-OR. Basically Orch-OR proposes that consciousness is the result of the self-collapse of a quantum wavefunction induced by quantum gravity at the microtubules of the neurons. The theory of Orch-OR complies with Sir Penrose's non-computational aspect of the human mind.
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2 of 3 people found the following review helpful By Prometheus on 3 Jun 2001
Format: Hardcover
Penrose's book expels the myths surrounding artificial intelligence and in doing so also reveals a great deal of physics to the layman. He gives an expose of the twin pillars of modern theoretical physics, namely quantum theory and relativity and uses this scientific knowledge to justify his views on the nature of consciousness. A sequel to his previous book "The Emperor's New Mind", Penrose covers subjects as diverse as superstring theory and brain neurology, in an attempt to justify his conviction that algorithmic computers cannot truly achieve artificial intelligence or consciousness. Along the way, "Shadows of the Mind" also offers tentative suggestions for the way forward in fundamental physics and much of its contents would therefore be of interest to students of the subject.[A more pictorial approach to some of these subjects can be found for example on lulu.com/"Special Relativity: A concise guide for beginners."]
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By adrian stephens on 9 Oct 2014
Format: Hardcover
good book. good seller
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Most Helpful Customer Reviews on Amazon.com (beta)

Amazon.com: 37 reviews
30 of 32 people found the following review helpful
General comments 27 Dec 1999
By "mervyn@ynnmail.com" - Published on Amazon.com
Format: Paperback
This book is a significant improvement on Penrose's previous writing of similar scope, "The Emperor's New Mind", especially that he has more specific ideas on the actual biological manifestations of the noncomputational processes he seeks as basis for consciousness. Even if one does not agree with his arguments, there is a great amount of information on physics and so on, written in a style that makes the book a pleasure to read. A previous review mentioned that many have opposed the logical arguments from the first part of the book. Penrose, however, has replied quite well to many criticisms (see PSYCHE, an electronic journal on consciousness), and I think it is premature to pass final judgement. For an alternative, not necessarily incompatible, view of consciousness I highly recommend "The Feeling of What Happens" by the distinguished neurologist Antonio R. Damasio (or at least check out his article "How the Brain Creates the Mind" in Scientific American, December 1999).
41 of 50 people found the following review helpful
A work with far reaching implications 22 May 2000
By A Customer - Published on Amazon.com
Format: Paperback Verified Purchase
Between the beautifully written prologue and epilogue, this book approaches a range of topics in modern physics in a unique and readable way. Through a continuation of some earlier work, Penrose furthers an argument for brain function and conciousness that many in the artificial intelligence field will not appreciate. He presents his case that the human mind will never be simulated with digital a computer, no matter how complex. But that is not his main focus of this book.
Even more facinating are his calculations which indicate how mathematically unique our existence is under the 2nd law of thermodynamics. To me, it's ultimately ironic that the physical principal which orders our universe and makes intelligent life possible (the 2nd law), is the result of an unimaginably improbable set of initial conditions. Although Penrose never invokes the concept of a creator or supreme being, in my mind, this poses an interesting challenge to those in the scientific community who claim our universe is simply the result of random particle collisions over a long period of time.
If we combine the concepts of similar structures scaling across space and time (tensegrity and fractals), with Penrose's ideas that consciousness may be associated with quantum gravity interactions in microtubules (present in all living cells), perhaps there is far more mystery and beauty to this existence than some would now believe...
This book was satisfying and throught provoking, and I highly recommend it to anyone interested in the mysteries of the very large and the very small.
17 of 19 people found the following review helpful
No other book tackles this subject so clearly 10 July 2008
By avarma - Published on Amazon.com
Format: Paperback
Just opening this book to a random page and reading that page - sets one's mind on fire.

The basic thread running throughtout the book is that of 'what is computable and what is not'. The process of 'Understanding' as humans know it - Penrose argues - is NON-COMPUTABLE. He provides brilliant examples of how computers can 'solve' any problem - without 'understanding' what they are solving (e.g. DeepThought and the simple chess move which stumped it).

This theme in itself would make this a worthwhile read. However - this book offers further gems from Quantum Physics - with perhaps the simplest and best explanation of lesser known quantum paradoxes such as the 'delayed choice' experiments. Godel's theorem is also dealt with lucidly.

Few authors can tackle the issue of 'mind and conciousness' without stepping into some mystical/unscientific goo. Penrose stays scientific - and works from facts and well known experiments.

I do not know of any other book that tackles this subject so clearly - and in such an exciting fashion. From my perspective - this clearly deserves 5 stars.
29 of 37 people found the following review helpful
Devastating 15 Oct 2003
By Alan Wilder - Published on Amazon.com
Format: Hardcover
Simple criticism is what Penrose does best. Finding contradictions, oxymorons, and mistakes is his specialty. His critique is certainly warranted now more than ever, as AI seems to be the slowest advancing field of all. In 1970s, we were 20 years from AI. Today, we are apparently 20 years from AI. I wager good money that in 2023, we will be 20 years from AI. How do we build something that we do not even know what it is? Is the mind computational? What is intelligence? These questions are still largely the realms of philosophy and not science. Thre are arguments, but the evidence is basically non-existent and largelly inferential; if it was any other field, literally negligable. But, some people argue, the very question of materialism rests in this quest. This is no necessarily true.
True AI is going to have to be more than a calculator. Actually, the best possible way to see if you believe in AI is to ask yourself: is a calculator a manifestation of AI? If not, there are problems with AI. Too many minds have built their fame and fortune arguing the opposite so the argument is not going away. Hence, I doubt this debate will be over any time soon.
However, in 20 years, I suspect nothing will have changed from the debate. Criticism of Shadows of the Mind usually involves oversimplification of Penrose's arguments. What you may think he says and what he does say are two completely different things.
Penrose has answered some criticism with rightful indignation in place. ....
8 of 9 people found the following review helpful
Deep Debate on Mind Machine Problem 27 Sep 2010
By Dr. Roy Simpson - Published on Amazon.com
Format: Paperback
Shadows of the Mind is undoubtedly a less populist book than its predecessor "The Emperor's New Mind". It is also significantly more technical in places than the predecessor. Its purpose is to extend the Godel based arguments used in ENM in several directions. Firstly to attempt to address various criticisms of the central argument of the previous book and then to develop some new ones. Also there is a discussion of the application to Robotics. An example of this sort of discussion is whether any capability of a Robot to learn would undo any of the Robot restrictions deduced in his basic argument. After all learning (human or robotic) will imply going beyond previous restrictions and being aware of new facts.

So there is a subtle argument needed to continue to show that despite this, humans will come out on top. If you are interested in this kind of subtlety after reading ENM then this is the book for you.

In effect Penrose is right at the heart of the Mind-Machine debate in this book. I give an overview of this debate as follows:

We need to find a scientific theory of the Mind. So we can examine what kind of cognitive or thinking device it might be, recognising that it also thinks about Mathematics. For that we need a model of cognition sufficiently general: the Turing Machine model is available and generally considered to be that model - there are no obvious rivals. So one can focus on whether the Turing Machine model could really be a model for the Human Mathematical Mind. If the answer is "yes" we would conclude also: Robots could have Minds.

Penrose draws the conclusion about mathematical reasoning that:

G: "Human mathematicians are not using a knowably sound algorithm in order to ascertain mathematical truth".

This statement isn't quite the statement that the Mind is not a Turing Machine (algorithm here), and some critics have attempted to expose the gaps. In this book Penrose discusses several lines of argument to close the gap. A possible rebuttal might be: "could mathematicians just be using unsound algorithms" - the faulty machine argument. This is very close to questions in the foundations of mathematics itself - after all is this suggesting that mathematics itself is fundamentally unsound? If so where is that unsoundness? So Penrose comes round to the conclusion step by step and through 100 odd pages, that the statement G above implies that indeed the Mind is not a Turing Machine.

This latter conclusion however introduces another problem: if the Mind is not a Turing Machine / algorithm then what sort of (scientific) model exists for it? At the end of the book Penrose examines a generalisation of the Turing Machine model (called Oracle Machines and also due to Alan Turing) and determines that a statement similar to G also applies to that model class as well. Thus the story is left incomplete and I would be tempted to say that somewhere a model M exists of which we can deduce:

"Human mathematicians are using M to ascertain mathematical truth"

However Shadows of the Mind ends without a discovery of that model M. So maybe the answer lies in studying Quantum properties, or in other aspects of these obscure machine models? If you want to be able to study this question further Shadows needs to be studied (and "studied" is the word)!
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