November 2006

John Clark


Second Nature: Brain Science and Human Knowledge by Gerald M. Edelman

Can you define “consciousness"? Most of us understand the word in context and can use it properly in a sentence. But asked to define it, we are suddenly rendered mute or at best unintelligible. It’s a word that is both vague (cannot be precisely measured) and ambiguous (having multiple meanings). No wonder scientists, philosophers and religious scholars have debated the source, meaning and nature of consciousness for all of recorded history. The argument continues, but a fascinating new book, Second Nature, Brain Science and Human Knowledge may bring us one step closer to resolution.

Nobel laureate Dr. Gerald M. Edelman offers a tantalizing theory of consciousness aimed at satisfying both the scientist and philosopher alike, but also appealing to the reader, like me, who is neither. There isn’t much here for the fundamentalist though. By naming his theory Neural Darwinism, and invoking evolution throughout, I suspect believers in the literal truth of religious texts will summarily reject the book before they get through the preface. Deeper into the book, Edelman does cleverly use the word GOD as an acronym for “Generator of Diversity.” Who can argue with that?
The title, Second Nature, is intended to distinguish human nature from nature in general. It calls “…attention to the fact that our thoughts often float free of our realistic descriptions of observed nature.” Edelman aims to communicate his proposed theory of consciousness without resorting to complex technical detail.  Even so, it is not for the faint of heart in terms of vocabulary. I suggest reading it with an Oxford English Dictionary slung low on the side in a quick-draw holster. Without it, be prepared to face some deadly sentences barehanded. For example: “The metaphorical capacity of linking disparate entities derives from the associative properties of a reentrant degenerate system.”

Before tackling this book (or a national spelling bee), I recommend familiarizing one’s self with a few words such as epistemology, ontological, epigenetic, sensorimotor, reductionism, structuralism, confute, or confabulate. The author does, however, define important terminology such as “reentrant,” which my research indicates is borrowed from the world of computer programming. (Ironic considering the author specifically and thoroughly debunks any notion of the computer as an analogy of how the brain operates.)

There are many profound insights about consciousness that one can take away from Second Nature without fully understanding all of the vocabulary. For me, the most important one begins to take shape even before finishing the introduction. Edelman paraphrases the work of 19th century psychologist and philosopher, William James, “…who pointed out that consciousness is a process whose function is knowing.” It is in James’s footsteps, claims Edelman, that his work follows.

Realizing that consciousness is not a “thing,” is a critical concept for understanding Edelman’s theory. Consciousness is not physically located anywhere in the brain or in the universe for that matter. It is also not a function of the brain. The brain does not function to generate consciousness; instead consciousness functions to increase and manipulate the brain’s store of useful information. In Edelman’s words, “consciousness is entailed by reentrant (brain) activity.” You will have to read the book and use your dictionary to fully comprehend Edelman’s brilliant but simple definition of consciousness.

Edelman builds his brain based approach to human consciousness on the foundation that consciousness is a property that emerges as different brain areas (with fuzzy boundaries) rapidly communicate back and forth across a network of billions and billions of neurons -- neurons constantly firing and rewiring themselves. Indeed, the catchiest phrase in the book is one previously coined by Edelman: “Neurons that fire together wire together.” Some pathways are strengthened and others weakened by subsequent iterations of this back and forth communication process. On a simplistic level, survival of the strongest neural pathways shapes our memory, thoughts, emotions and behaviors -- hence Neural Darwinism.

Edelman’s brain-based approach is not purely scientific. Neither is it purely psychological -- it is a hybrid. Science can attempt to describe consciousness and its origins, but it cannot prove it or replicate it. Psychology and philosophy fail because neither approach correlates the biology of the brain with consciousness even though common sense tells us they are related.

If the author’s hybrid approach is going to be taken seriously, it must account for all aspects of brain activity. Edelman does an excellent job organizing chapters of the book around important topics including creativity, abnormal states, and causation, illusions and values. Although the language can be difficult, each chapter begins with interesting and relevant quotations and includes helpful summaries of prior information. Each chapter ends with a well-worded transition introducing the following chapter. Overall, the book is organized to provide important general background information, a description of the Neural Darwinism theory, and applications as well as implications.  

Anyone intrigued by the subtitle, Brain Science and Human Knowledge, he who also enjoys abstract intellectual discussion, should enjoy reading Second Nature. It is a physically small book containing giant ideas. Those with patience will be rewarded with a fascinating high-level perspective on the latest theory of knowledge and human consciousness.

Second Nature: Brain Science and Human Knowledge by Gerald M. Edelman
Yale University Press
ISBN 0300120397
224 Pages