The Four Realms of Existence: A New Theory of Being Human

About the Book

One of the world's leading experts on mind and brain takes us on an expedition that reveals a new view of what makes us who we are.

Humans have long thought of their bodies and minds as separate spheres of existence. The body is physical-the source of aches and pains. But the mind is mental; it perceives, remembers, believes, feels, and imagines. Although modern science has largely eliminated this mind-body dualism, people still tend to imagine their minds as separate from their physical being. Even in research, the notion of the "self" as somehow distinct from the rest of the organism persists.

Joseph LeDoux argues that we have hit an epistemological wall-that ideas like the self are increasingly barriers to discovery and understanding. He offers a new framework of who we are, theorizing four realms of existence-bodily, neural, cognitive, and conscious.

The biological realm makes life possible. Hence, every living thing exists biologically. Animals, uniquely, supplement biological existence with a nervous system. This neural component enables them to control their bodies with speed and precision unseen in other forms of life. Some animals with nervous systems possess a cognitive realm, which allows the creation of internal representations of the world around them. These mental models are used to control a wide range of behaviors. Finally, the conscious realm allows its possessors to have inner experiences of, and thoughts about, the world.

Together, LeDoux shows, these four realms make humans who and what we are. They cooperate continuously and underlie our capacity to live and experience ourselves as beings with a past, present, and future. The result, LeDoux shows, is not a self but an "ensemble of being" that subsumes our entire human existence, both as individuals and as a species.

About the Author :
Joseph E. LeDoux is Henry and Lucy Moses Professor of Science and Professor of Neural Science, Psychology, Psychiatry, and Child and Adolescent Psychiatry at New York University. He directs the Emotional Brain Institute at NYU. His many books include Anxious and, most recently, The Deep History of Ourselves.

Review :
LeDoux’s aim is to provide a new theory of being human by dividing our evolutionary past into four realms: biological at the bottom, then neurobiological, cognitive and conscious…Along the way are excellent accounts of the evolution of brain structures and cognitive abilities. [LeDoux] suggests that there are four basic varieties of life on Earth: biological, neurobiological, cognitive and conscious. The book provides an in-depth description of these realms (I found the cognitive one especially thought-provoking) and describes how they evolved. A rigorously scientific yet eminently readable exploration of what it means to be human…[LeDoux] delves into complex notions of personality and the self, the construction of internal narratives, and memory, elegantly making the case for the emergent properties of the mind without recourse to an undetectable soul or reducing the complexity of human existence to merely physical factors. The result is a finely wrought, thought-provoking feast for the mind. Joseph LeDoux is one of the most influential researchers and engaging writers in contemporary neuroscience. In The Four Realms of Existence, LeDoux takes the reader on an eye-opening journey into some of the most profound mysteries of mind and brain. Full of provocative ideas and startling insights, this captivating book is essential reading for anyone interested in understanding the basis of human experience. Joe LeDoux is a leading light in the neuroscience of consciousness, and his new book is fascinating, engaging, and provocative. He proposes that consciousness is a kind of story that the brain tells itself, and he backs up this intriguing proposal with a wealth of evidence, including many discoveries of his own. Well worth reading. LeDoux is a deep and synthetic thinker, aiming to advance our understanding of the mind in a way that is consistent with our best science and philosophy. His encyclopedic mastery of evolutionary biology, neurobiology, cognitive neuroscience, psychology, and the philosophy of mind allows him to build a theory of mind that does justice to the theory of evolution. A terrific book! One of our great scientific storytellers, Joe LeDoux deftly exposes the insufficiencies of current understandings of self and personality to capture the totality of who and what a person is in this fascinating and deeply researched book on what it means to be human.