Shadows of the Mind, Roger Penrose
Raymo, Chet
WHAT MAKES THE MIND LEAP? SHADOWS OF THE MIND A Search for the Missing Science of Consciousness Roger Penrose Oxford, $25,457 pp Chel Raymo Years ago, one of my professors distributed to...
...However, this remains an important book, with much that is valuable to say about the science of mind...
...indeed, few readers will be qualified by training or temperament to follow the author through all the steps of his argument...
...It is not an easy read...
...C Physical activity in the brain is the basis for awareness, but this activity cannot even be simulated computationally...
...In the present work, Penrose throws commercial caution to the wind...
...From this Penrose concludes that human thinking contains a noncomputational ingredient...
...What might it be...
...Shadows of the Mind is not so much an explanation of consciousness as a program for future research...
...a data bit is either a one or zero...
...Penrose is the Rouse Ball Professor of Mathematics at the University of Oxford...
...We need to understand how the indeterminate quantum behavior of individual elementary particles achieves coherence across broad regions of the brain...
...Elementary particles—photons or electrons for example—follow a different logic...
...What is missing is a satisfactory theory connecting the quantum and classical worlds...
...This is his second book to address the problem of explaining consciousness...
...People with traditionally religious world views tend to affirm D Penrose stakes his claim on C He believes awareness is a manifestation of the physical brain, but that it arises from activity that cannot be programmed into a computer, no matter how complex that machine might be...
...D. Consciousness cannot be explained by physical, computational, or any other scientific terms...
...The results took us by surprise...
...Computers are binary devices, both in logic and operation...
...the brain is a computer made of meat...
...His broad expertise, incisive intelligence, and philosophical tentativeness are the strengths of this work D 22...
...This is a sketchy summary of a dense and difficult book...
...The hard scientists hedged their statements with probability In his new book on human consciousness, Roger Penrose, a physicist and mathematician, is appropnately tentative His subject is a big one and his speculations bold, but he hedges them with a befitting humility...
...Attributes of mind such as insight, intuition, and self-awareness will forever transcend any algorithm or computation Penrose centers his argument on a famous theorem proved by the Czech-born logician Kurt Godel in 1931 It states that any rigidly logical mathematical system contains statements that cannot be proved or disproved on the basis of axioms within the system In other words, there are mathematical statements whose truth is accessible to human intuition and insight which cannot be proven by the apphca21 tion of any set of rules...
...A transistor is either on or off...
...Mind-body dualism...
...A ghost in the machine1* Almost certainly not, says Penrose Then what...
...Penrose believes the noncomputational qualities of human consciousness spring from Z-mystenes of the quantum world, perhaps having their origin in the microtubules of the cytoskeleton of the brain's neurons...
...Most artificial intelligence researchers and neuroscientists hold to A or B, for the obvious reason that these positions offer hope of timely success...
...SHADOWS OF THE MIND A Search for the Missing Science of Consciousness Roger Penrose Oxford, $25,457 pp Chel Raymo Years ago, one of my professors distributed to his class a collection of articles by philosophers and theologians, on the one hand, and hard scientists, on the other...
...He asked us to count qualifiers—words like "maybe," "perhaps," "possibly...
...B Computers may simulate human consciousness without actually being conscious, in much the same way that a computer can simulate a hurricane without actually being a hurricane...
...These mysteries—called Z-mystenes by Penrose, from puZZle— violate classical common sense, but they have been experimentally demonstrated...
...Shadows of the Mind is profoundly mathematical both in content and spirit...
...He looks to the strange behavior of the quantum world for his answer...
...However, all who are seriously interested in the scientific explanation of consciousness would do well to make themselves aware of Penrose's C-view, as well as A/B works such as Francis Crick's Astonishing Hypothesis and Daniel Dennet's Consciousness Explained...
...Apparently enough did to make the book a success...
...He has worked with Steven Hawking on the structure and history of the universe, he is a computer whiz and the closest thing to an all-round genius we are likely to find...
...The first, The Emperor's New Mind, a rather technical treatise on physics, computers, and the mind, climbed onto the New York Times' s best-seller list Its success undoubtedly reflected Penrose's stature as a thinker, and our own interest in the phenomenon of self-awareness...
...He ignored that advice, and asked his readers to hang in even in the face of an occasional formula...
...The problem is that neither Penrose nor anyone else fully understands how microquantum magic is translated into macrobehavior...
...In that earlier book, Penrose said he had been advised that each formula or equation would cut his readership by half...
...According to Penrose, the leap of imagination, the spark of insight, are macromanifestations of the nonlocal, noncausal, yes-and-no laws of micronature...
...The philosophers and theologians tended to make unqualified assertions...
...According to the rules of quantum physics, there is a sense in which a particle can be in two places at the same time The properties or states of quantum systems are said to be entangled, so that even after separation two photons emitted in opposite directions from the same source seem to know what the other is doing, instantly, across centimeters, perhaps even lightyears, of space...
...Until such a theory is found, Penrose believes, no scientific explanation of human consciousness will be forthcoming...
...The truth is, we do not yet know enough about consciousness to choose among A, B, and C. As for D, no scientist I know of seriously entertains the possibility that the mind exists independently of the brain, or that it will forever elude scientific explanation, but even about this possibility Penrose expresses appropriate caution...
...At issue is whether computers can become conscious or self-aware Penrose lists four attitudes toward the question A. Consciousness is mere computation...
Vol. 121 • December 1994 • No. 22
