This book is an evolutionary history of life on earth. Its focus is not the evolution of the structural/functional adaptations found in any biology textbook, though these are necessarily discussed in a general way. It�s primarily concerned with consciousness, with what the organism experiences.

     Just how far back into evolutionary history consciousness extends, of course, is a highly controversial issue, and one which we will probably never resolve with certainty. We know we are conscious, and most people would probably extend consciousness to other mammals, but when it comes to lower vertebrates, let alone invertebrates, there is no consensus. This book takes a �what if� approach. What if all forms of existence were conscious to some extent, a view known as panpsychism or panexperientialism? Based on those aspects of their function and behavior that we can actually observe and measure, what can we say about what this consciousness is like? The resulting story is one in which consciousness becomes increasingly more complex over evolutionary history, yet is based on facts of animal behavior that any reader, regardless of personal views on consciousness, can accept.

     In order to simply a vast amount of scientific literature, the book focuses on two general properties of consciousness and its behavioral manifestations: the experience of an outer world embedded in space and time; and that of an inner self that is defined by its relationship to other organisms. Two key claims made are that 1) dimensions of externally-perceived space and time have emerged more or less one at a time over the course of evolutionary history; and 2) the number of spatial/temporal dimensions experienced by any organism in the outer world is closely related to experienced inner dimensions in its relationships with other organisms.

     For example, the simplest invertebrate organisms experience one dimension of space, in the form of intensity discriminations made of simple stimuli such as light, touch and chemical substances. Closely correlated with this one-dimensional experience of the outer world is the ability to make simple self-other discriminations, in which the organism in effect distinguishes itself one-dimensionally from the outer world. Somewhat more evolved invertebrates, such as arthropods, experience two dimensions of space, their perception being largely limited to shapes, contrasts, and surfaces. They can also distinguish between two dimensions in their relationships with other organisms, as exhibited in the ability to discriminate such classes of other as male vs. female and kin vs. non-kin. The most highly evolved invertebrates, as well as all vertebrates, experience additional dimensions of space and/or time and make still finer discriminations among other organisms.

     The evolutionary story is not confined to organisms, however. The book argues that the same kind of dimensional relationships exist on lower levels of existence. Thus there are atoms that recognize and interact with other atoms in various degrees of dimensions, and there are cells that recognize and interact with other cells in different numbers of dimensions. Again, the minimal claim being made is that the function and behavior of these lifeforms can be understood in terms of dimensions, while leaving it up to individual readers to decide whether this could reflect a similar dimensionality of consciousness.

Review by Kirkus Discoveries

     A lucid, thought-provoking and wide-ranging metaphysical treatise by novelist, scientific researcher and Stanford Ph.D. Smith.

     Heralded as �the first complete history of consciousness ever written,� The Dimensions of Experience covers an astonishing amount of ground, from evolutionary theory to postmodern linguistics, physics and even obscure Victorian literature. Smith�s central contention is that �the miraculous is much closer to home� than many human beings understand. By this he does not mean a hidden realm of elves and dragons�or any sort of religious transcendence, at least as understood in the biblical sense�but a miracle of dimensions. �However many dimensions there are in the universe, we�all of us, all forms of life�exist in all of them,� Smith argues. �They are all within our reach. What we lack�some species more than others, but again, all of us to some extent�is the ability to experience all of these dimensions.� Over 11 tightly written and edited chapters, Smith goes on to explicate the evolution of consciousness and how we came to understand the world as we do today. He discusses transcendental meditation and the benefits and fallacies therein; he ventures bravely into the world of coral reefs, worm colonies and bacteria, showing how even the simplest of organisms experience life in a range of dimensions. �According to science,� he writes, �the three major dimensions of space are a condition of all existence, within which the entire evolutionary history of earth has played out.� Not so, he counters. The Dimensions of Experience makes the case for a more dynamic form of evolution, where beings evolve through time and space, but also through dimensions we do not yet properly understand. Smith�s great accomplishment is verisimilitude; he holds forth with equal skill on both the biology of proto-organisms and the knottiest work of post-structuralists like Derrida, and he weaves every chapter deftly into a convincing narrative.

     An engaging, supple scientific text, blessedly free of weighty academic jargon.

Preview coming soon.

When I received my Ph.D. in Neuroscience nearly 40 years ago, consciousness was considered a fringe area by most scientists. There was a broad consensus that, at best, science still lacked an understanding of the brain deep enough to permit studies of consciousness; and at worst, that the phenomenon itself was outside the bounds of science entirely. Many scientists were uncomfortable with even mentioning the word. The focus was strictly on the brain and its functions, as if organisms including ourselves could be understood without regard to our immediate experience of the world.
That environment has profoundly changed during my professional career. I have seen not only powerful new advances occurring in technology, such as magnetic resonance imaging (MRI), but of greatest significance, the breakdown of barriers between academic disciplines. The importance of interdisciplinary communication was already becoming recognized back in the 1960s when I began my career, but it has continued to expand. Few back then would have imagined today�s conferences in which philosophers, psychologists and anthropologists, let alone artists, writers and musicians, mingle with molecular and cell biologists, neurophysiologists and computer scientists. Immersed in this interdisciplinary spirit, this book draws from a wide variety of sources to develop a plausible story of how consciousness has evolved: the forms it has taken, with regard to both experience of the external world, and the sense of self and its relation to others.
Throughout my adult life, I have also followed consciousness in a very different way, through spiritual practice. My own experiences, as well as those of others, make it clear to me that there is a higher state of consciousness than our so-called waking state. While scientific study of this higher state remains difficult, I believe it demands inclusion in any discussion of evolution. There is no reason to believe that evolution of consciousness has finished with that of our species.