Product Description

Shadows of the Mind is a profound exploration of what modern physics has to tell us about the mind, and a visionary description of what a new physics - one that is adequate to account for our extraordinary brain - might look like. It is also a bold speculation on the biological process that makes consciousness what it is. In this illuminating book Penrose provides powerful arguments to support his conclusion that there is something in the conscious activity of the brain that transcends computation - and will find no explanation in terms of present-day science.

Product Details

• Amazon Sales Rank: #29742 in Books
• Published on: 1995-09-07
• Original language: English
• Binding: Paperback
• 480 pages

From the Publisher
By the author of The Emperor's New Mind 'One of the most important works of the second half of the twentieth-century' The Times

About the Author
Roger Penrose is Emeritus Rouse Ball Professor of Mathematics at the University of Oxford. He has received a number of prizes and awards, including the 1988 Wolf Prize for physics which he shared with Stephen Hawking for their joint contribution to our understanding of the universe.

Customer Reviews

Mathematics, science and the working of the brain
The purpose of this book is to explore the connection between what is known in the areas of mathematics and physics to the way in which human brains function. Quite apart from this, the book is an excellent commentary on some on the more significant developments in physics and mathematics during the last hundred years. It is written so as to be readable by the non-scientist but those without a scientifc background could find some parts heavy going.

A great book for anyone who knows they are not a computer
Shadows of the mind is a terrific book from a brilliant author.

Penrose's argument that conscious thought is not based on computation as we understand it is sound. Whether this can be strictly ascertained from Godel's theorem is still open to question I think.

However his overall conclusion that when we think, we may be using quantum mechanical counterfactuals to take us beyond the limits of computation, is an intriguing possibility.

I would recommend this book strongly to anyone with a reasonably high level of scientific education. Its hard work to read because the questions he asks are so deep and his approach to answering them is so exhaustively rigorous.

Penrose is not an evangelist like Richard Dawkins so his writing style is not as engaging to a popular audience. Nevertheless it is worth ploughing through this book to at least be rewarded in the end with the firm belief that one is definitely not merely a computer controlled robot!

Nicely written but wrong
Penrose writes lucidly, and while not as engaging as some other pop science writers (e.g. Dawkins) is still easy to read.

However he is also a grossly mistaken man who has strayed far from his own field - a good Mathematical Physicist he may be but he's no Philosopher or Psychologist.

The main argument of the book centres around Godel's Theorem (or rather Turing's formally equivalent version) to show that mathematical reasoning is non-computational.

This basically begins with the premise 'assume that A is the algorithm which can decide if any given algorithm will terminate' and ends with the contradiction 'if A terminates then A never terminates'.

Penrose concludes that therefore A never terminates and that we must have used a non-algorithmic method for telling this ourselves (since A is the best algorithmic method).

However Penrose has misrepresented Godel, the actual conclusion is the falsity of the premise (that there could ever actually be an algorithm which would tell us if any algorithm terminates).

If Penrose is right and A never terminates then he has violated the initial premise of what A does and invalidated the whole argument.

The whole book then flows from this failure of logical reasoning to a far-out theory of consciousness that is highly implausible and scientifically naive.