The Nature of Consciousness

Piero Scaruffi

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These are excerpts and elaborations from my book "The Nature of Consciousness"



By the time you finish reading this book you will be a different person.  I am not claiming that this book will change the way you think and act. I am simply referring to the fact that the cells in your body, including the neurons of your brain, are continuously changing. By the time you finish reading this book you will "literally" be a different body and a different brain. Every word that you read is having an effect on the connections between your neurons. And every breath you take is pacing the metabolism of your cells. This book is about what just happened to you.


As with any book worth reading, the goal of this book is to fill a gap. In my case, the gap is a lack of books that provide an interdisciplinary account of the studies on the mind carried out around the world. While many books carry that label, most of them focus on the one or two disciplines or theories that the author intends to defend or attack.

First and foremost, my book aims at providing an accessible and stimulating introduction to those studies across a number of disciplines: Philosophy, Psychology, Computer Science, Mathematics, Biology, Neurology and Physics. This book contains a brief description of every single modern theory (about Consciousness, Cognition and Life) of which I am aware.

This book was originally born to provide an overview for ordinary humans of the philosophical mind-body debate, of neurological models of the brain, of computational theories of cognition (Artificial Intelligence, Connectionism), of post-Darwinian biology, of theories on memory, reasoning, learning, emotions, common sense, dreams, language, metaphor, of modern Physics (Quantum Theory, Non-equilibrium Thermodynamics, Relativity Theory), and, last but not least, consciousness. It was originally meant as a compendium of the scientific ideas that are likely to shape the intellectual scenario of the third millennium. And I was its original reader.

This book also offers a humble personal opinion on what the solution to the mystery of consciousness may be. But that is not the centerpiece of the book.

A popular question of our times is: What is the meaning of life? I always found that question misleading, because first we should be able to answer the more basic question: What is the meaning of matter? This book can’t answer either, but at least tries to make the connection.

Physics has explained everything we have found in the universe. We know how the universe started and how it will end. We know what drives it. We know what makes it. Our knowledge of fundamental forces and elementary particles is increasing daily. Two things remain to be explained: how am I alive and how do I think. What does it take for something to be alive and to think? Can we "build" a machine that thinks and is alive? What is thought (consciousness)? And what is life? Physics provides no answer. Historically speaking, Physics never tried to give an answer. Life and thought were considered beyond the reach of formulas. Today, instead, scientists from different disciplines view living and thinking as physical phenomena to be studied the same way we study galaxies and electricity. The most important revolution of our century could be the idea that thinking and living can be explained by mathematical formulas, just like any other phenomenon in the universe. Science may never be the same again, literally. Any scientific theory that does not provide a credible account for consciousness and life is faulted from the beginning, as it ignores the two phenomena its own existence depends upon. We are alive and we are conscious: we know that much.

We live in an age in which the study of consciousness, cognition and life is no longer philosophical speculation. It is, instead, affecting a growing number of disciplines. For the first time in history there is a convergence of specialists (neurologists, biologists, physicists, mathematicians, computer scientists, psychologists) onto one subject.

A new view of nature is slowly emerging, which encompasses both galaxies and neurons, gravitation and life, molecules and  emotions.  In what represents the culmination of centuries of studying nature, humankind is now approaching the thorniest  subject  of  all: ourselves. We are part of nature, but, historically, Science left us in the background, limiting our role to the one of observers.

For a long time we humans have enjoyed this privileged status. But we seem no longer capable of eluding the fundamental issue: that what we have been studying for all these centuries is but us, albeit disguised under theories of the universe and of elementary particles (theories of what “we” see). And now it is about time that we focus on the real subject. The human mind appears to us as the ultimate and  most refined product of life. And life appears to us as the  ultimate  and  most  refined  product  of  matter. Now we need a theory of the universe in which consciousness, cognition and life are not oddities, but building blocks.

The fact that we do not have yet a good theory of mind  probably means  that we do not have a good theory of the universe. Consciousness is perhaps the great mystery of the universe. And the reason may very well lie in a fundamental inadequacy of our Science to explain natural phenomena. In a sense, the new science of mind is doing more than just studying mind: it is indirectly reformulating the program of Science in general.

Future generations will be amazed that it took thousands of years (and hundreds of years since the scientific revolution) to realize how important consciousness is to understand the world and ourselves.

At every point in the history of Science, a paradigm shift allowed for the explanation of previously unexplained phenomena.

The challenge, now, is to explain why we are here.

And what we are.

Ultimately, this book is about the gap between "I" and "me".


This book was begun in 1997. It was published as “Thinking about Thought” in 2003. It has been greatly revised and expanded since then. This new edition includes material that originally appeared on my website Click on “Science” and register to the monthly newsletter if you wish to receive future updates.

The website is also the easiest way to find out my email address. I welcome feedback from readers, whether it is typos or opinions.


Piero Scaruffi

Redwood City, November 2006



About Me

Few people have the qualifications to write such an ambitious survey of a brand new discipline. I confess i am not one of them. After leading the Olivetti Artificial Intelligence Center for several years, in 1995-96 i spent two years at Stanford University studying Cognitive Science (thanks to a visiting scholarship kindly granted by Robert Engelmore at the Knowledge Systems Laboratory). That was, in retrospect, the beginning of this book. I simply gathered information from all disciplines with the aim of working out a synthesis of sorts. I guess it will remain the goal of my life, although i have missed my chance of working inside academia.

My background is a mess. I graduated in Mathematics but my thesis was on theoretical Physics (that’s where i got my introduction to Quantum and Relativity Physics). I worked in the software industry and eventually did research on Artificial Intelligence.

In my other lives, i write about music, cinema and literature, and i am working on a history of knowledge from the beginning of human civilization to our days. I have published poetry that won a few awards. I have traveled to more than 120 countries.


How To Read This Book

I think that all readers will be interested in the main ideas surveyed within each chapter, but probably most readers will not be interested in the details of each and every chapter.

Each chapter contains a short introduction to the subject, and then a series of paragraphs that summarize the theories of the main specialists in the field.

I rarely take sides. I summarize a scholar's work and let you decide.

(I apologize with the scholars: a one-page summary of their work is, of course, a very superficial reading of their theories. The goal of this book is to offer “breadth”, not “depth”).

What is subjective is the selection: i do make a selection for the reader, not only focusing on theories that represent real paradigm shifts but also omitting (with a few exceptions) those theories that are too unscientific for my taste. Much of what i read in Psychology and Philosophy, for example, is incredibly trivial or incompetent (unaware of research in other fields).

As you advance into the chapter, the theories get more difficult and sometimes repetitive. Depending on your level of interest, you may want to absorb all the details or just skip to the next chapter.

My own ideas are usually left for the end of each chapter. Needless to say, you don't miss much if you skip my ideas.

I have a feeling that, for most readers, the best way to read this book is in many stages: first surf the chapters (focusing on the first half of each chapter), then re-read the book going a bit further within each chapter.

A generous bibliography at the end of each chapter should help you select what you want to read next, depending on what intrigued you most (titles in bold are those recommended for beginners).

The core material on Cognitive Science is divided into chapters that roughly correspond to cognitive faculties (memory, dreams, emotions, language, etc). But the “peripheral” chapters are no less important, and in fact, take up most of the book. There is a first chapter devoted to a survey of Philosophy of Mind, followed by three chapters on Machine Intelligence. There is a lengthy chapter on Physics flanked by three chapters on Biology.

Beginning with a survey of Philosophy may not be the best way to introduce a book that promotes a new science. While Philosophy matters less when hard data are available, philosophers of mind did frame the problem. The reader probably has her own strong opinion on what consciousness is and where it comes from. After reading the first chapter and the different theories of all those philosophers, the reader with strong opinions will probably realize that her convictions are a bit amateurish. Thus that first chapter may be helpful to “clear the air”.

Ditto for Machine Intelligence. Whether “intelligent” (or, better, conscious) machines are feasible or not, the program of building one has forced people to think about what consciousness is and where it comes from. The fact that we are not even close to building such a machine means that it is either impossible or we are still in the dark.

The chapters on Biology provide the kind of general knowledge that is needed to situate cognition in the proper context. Our brain acts in a world. An organism does not live in an empty universe. The origin of life and its evolution are also relevant. The nature of altruism (that seems to defy the essence of Darwinism) is important to understand our mind. The physical and mathematical theories of life are basically abstracting general principles applicable to other fields (possibly neurobiology itself). Throughout these chapters i introduce the basic facts of life (e.g., the genetic code, DNA, the structure of the cell, etc).

The chapter on the brain is relatively straightforward: it summarizes what we know about the structure and functioning of the brain. Ditto for the three chapters on Biology. Both Neurology and Biology are essential to understand the “what” and the “why” of cognition. The chapters on dreams and emotions are much more speculative.

There are four chapters on Language, each one addressing a different dimension (structure, origin, metaphor, pragmatics). The chapter on meaning is rather technical (by the standards of this book) but i felt that a brief introduction to the debate on truth and meaning could not be omitted. Skip it if it sounds tedious.

The chapter on Physics is essential. Every other chapter is useful for its philosophical, biological, mathematical or psychological speculations, but, at the end of the day, it is Physics that best summarizes our knowledge of the universe. Anybody who has an opinion on life, cognition or consciousness without being fluent in Quantum Mechanics and Relativity is simply bluffing.

The last chapters attack consciousness, surveying all the main theories that I am aware of. The three chapters cover biological theories of consciousness (that are based on classical Physics), theories of how consciousness emerged in evolution, and finally theories of consciousness based on modern Physics (not classical Physics). Like in most of the previous chapters, do not be surprised if you find contradictions: there is hardly any consensus yet on any of these theories. Physics is amazingly monolithic in its beliefs of what matter is and how it works. No such certainties exist in the science of consciousness. Finally, there is a separate chapter on theories of the self, although that has been discussed in previous chapters on the brain and on consciousness.

The last chapter is a collection of answers to “frequently asked questions”. As i lecture on these topics, the audience invariably ask me the same questions. For many years i resisted giving any credibility to these questions, but finally accepted the fact that i cannot elude them forever.

The character of these chapters varies wildly.

Depending on your background and interests, the first three or four chapters may excite you or put you to sleep. Whichever it turns out to be, do not assume that the rest of the chapters are of the same kind. In a sense, each one reflects the style and method of the discipline that it summarizes.

Previous readers consistently praised the second half of the book and criticized the first half. I still think that the first (more technical) half is necessary to understand the context of the second (more speculative) half. Books that only deal with life or consciousness are not educating the reader: they are merely teasing the reader.

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