A Place for Consciousness

Probing the Deep Structure of the Natural World

1/1/2005

By Gregg Rosenberg

Oxford University Press 2004

Book Review
Reviewed by John Bringardner

Gregg Rosenberg studied artificial intelligence before taking a detour into the dot-com frenzy of the late 1990s. He made his money and got out, only to return to his first love, the problem of consciousness. Perhaps that experience in the real world, if such a term can be used to describe that era, accounts for the kind attention paid to non-specialist readers of his first book, A Place for Consciousness: Probing the Deep Structure of the Natural World. Rosenberg makes profound new arguments for analyzing consciousness beyond the current scope of physics, or physicalism, and offers them in a tightly written text, detailed enough to satisfy the professional philosopher, but accessible to a wider educated public.

“Scholars should see it as an attempt to make a substantial advance in the development of Bertrand Russell’s Structural Realism by borrowing some inspiration from Alfred North Whitehead’s process philosophy,” he says in his preface. “General readers can simply see it as an attempt to explain the mystery of the soul.”

Born in the early papers of an undergrad making his way through books like Douglas Hofstadter’s Gödel, Escher, Bach, and Metamagical Themas, the end result is a welcome attempt to step beyond the physicalist argument for consciousness, which currently hold most sway in the philosophy of mind. A Place for Consciousness is an amazing example of what The Economist has called “one of the most striking developments in Anglo-American philosophy: the return to full-blown and often crazy-sounding metaphysics, argued out with the daunting resources of modern logic.”

Rosenberg cites Russell, one of the founders of modern logic, who once said that “the aim of philosophy is to start with something so obvious as not to be worth mentioning and to end up with something so absurd that no one will believe it.” Consciousness is simply the state of being aware of something internal or external to oneself, a state in which most of us exist most of the time and never much consider (Terri Schiavo being the exception that proves the rule). In fact, when we talk about human life, we are mostly talking about our conscious experience of both things that happen to us and the things we do. But what is consciousness itself? A thing we can touch? A metaphysical property of the soul, given us by God? A combination of the two?

Descartes famously meditated on the subject, but was stuck with an unsatisfying answer to the mind-body problem, positing that the mental and the physical meet each other in the pineal gland, a small part of the epithalamus, near the center of the brain. He believed in an ontology of substance and properties, the former a metaphysical buttress for the latter. The mind, for Descartes, is a substance with the properties necessary for rationality and causal power. Though he never quite understood how the mind interacted with matter, he believed that it must occur. “It seems surprising that our brains would support consciousness,” says Rosenberg “but we know firsthand that they do.”

These days, most philosophers and scientists consider brain activity the physical basis of mental activity, a position known as physicalism. Physicalists believe that “everything is physical in some sense.” Among those who find this theory lacking is David Chalmers at the University of Arizona, editor of the “Philosophy of Mind Series,” of which A Place for Consciousness is the latest release. Rosenberg wants to lay a framework for many of the theories cultivated by Chalmers, Galen Strawson, Michael Lockwood et al., a solid foundation for consciousness that is intellectually rigorous, one that does not introduce the concept ad hoc. He calls his theory Liberal Naturalism:

Like physicalism, Liberal Naturalism holds that the world is probably composed from a single fundamental kind of thing… However, like substance dualism [Descartes’ view], Liberal Naturalism holds that some of these properties and laws are not physical properties and laws. What ties the physical and nonphysical together is a deeper kind of thing of which they are both aspects.

The concept is simple, though it might frighten some with its metaphysical undertones. Rosenberg, starting with the fundamentals, uses a simple game called Life as a model of the physical world to show that the facts of Life (and, by extension, physics) do not entail consciousness, which requires “further facts.” The though experiment is a basic physics that does not assume consciousness as its end result. We must search out those facts about phenomenal consciousness. But as he shows, the game can only produce a structure. To put it in human terms, the game can only create a zombie, a creature that resembles us physically, but is bereft of consciousness.

Rosenberg solution is to build a structure underneath physics without reference to consciousness, but one that matches the properties we require of proto-consciousness. This layer is causation.

“To find a place for consciousness, we need tests for the minimal adequacy of proposed explanations and also a class of problems able to provide clues that help us triangulate to the point of fundamental completeness in our knowledge.” The meat of the book concerns itself with this triangulation, primarily by way of testing physicalist and antiphysicalist ontologies, and causation. This outline detailing “epiphenomenalist worries” is illustrative:

1. The physical facts alone do not entail the facts about conscious experience.

2. We can conclude from (1), that 2. Experience is a nonphysical aspect of the world.

3. A completed physical theory is, in principle, a descriptively adequate characterization of the dynamical evolution of the physical world.

4. We can conclude, from (3), that 4. Our physical explanations are complete explanations of the causation involved in producing bodily movements.

5. We can conclude, from (2) and (4), that 5. Consciousness lies outside the causal structure of the world, that is, it is an irrelevant epiphenomenon.

Rosenberg shows one at a time what happens with a denial of each premise, as well as acceptance of all of them, leading variously to reductionism, nonreductive physicalism, interactionist dualism, parallelism and more. “The one strategy that philosophers have not explored well,” he says, “is a denial of premise (4), where (4) is the inference from the adequacy of physical theory to conclusions about the causal completeness of physical explanation.”

He argues that physics might only describe an aspect of causation, and this acknowledgement allows us to look elsewhere for a full explanation. So what is it that is needed beyond the physical to create consciousness?

Rosenberg builds a theory of consciousness out of the interactions between natural individuals. This is a technical term, referring to single, propertyless things rather than human beings. These individuals are like atoms, combining with each other in infinite but rules-based ways, to various ends. Individuals combine into complete structures in Rosenberg’s cosmology, but when is a collection of individuals complete?

Boundaries help Rosenberg navigate the “Scylla and Charybdis” of Liberal Naturalism. These views are a matter of scope, the first panpsychism, zooming in to the subatomic level for signs of consciousness, versus the Charybdis yanking us far out into the cosmos, shooting past the level of humans, through societies up to solar systems and the universe for signs of a conscious system. How can we create a theory that gives human consciousness pride of place, again not in an ad hoc way? We need to find a middle ground where we as experiencing subjects exist.

“On Chalmer’s proposal we should be able to save middle-level individuals by allowing for all covarying subportions of space-time to be information spaces,” he says, “but then we are left with panpsychism run wild.” In other words, we are being too expansive. Rosenberg develops a theoretical framework, the Theory of Natural Individuals, which begins with his Theory of Causal Significance.

If the deep structure of the natural world is a structure of natural constraint, then the logic of constraint leads to a focus on selective inclusion and exclusion rather than production. Conceptualizing the world as the ultimate clique directs questioning toward the discovery of the secret character by which the world denies existence to so many things that could have been.

He shows that experience and causality cannot exist without each other, building an original theory of causation out of his critique of Humean theories. In so doing, he is establishing a framework for talking about consciousness in a way that does not appear ad hoc. He has done the hard work of building a well-argued and lucid account of causality, the causal mesh, that also accounts for consciousness. Nature’s deep structure consists of only three things: effective properties, receptive connections, and a metaphysical background of possibility.

A purely effective or purely receptive individual cannot exist, one requires the other. In Aristotle’s world, the purely effective individual is the unmoved mover, God. At what point do these complexes reach completion? Rosenberg admits he cannot say. The process of achieving “completion” reaches up the scale of connectedness as far as necessary. In other words, when a configuration has realized all of its possible connections. “This inductive definition allows the world potentially to be a place with a great depth of individuals corresponding to many layers of binding and completion before full determinateness is achieved.”

This is one point at which he comes into conflict with the prevailing orthodoxy. Here Rosenberg broaches panexperientialism, a view that sounds something like non-Western animistic beliefs. Even his effective/receptive dichotomy hints at experiences on the fringe of the sciences. He points out that “the idea that experiencing is a kind of openness to phenomenal content coheres with common phenomenological reports about meditative states in which people are denied normal sensory input.”

We are conscious because we are high-level natural individuals. Humans, and other conscious entities, experience the world through our receptive and effective constitutions. Rosenberg’s system solves an important problem in the philosophy of mind by showing how experience is involved in causal structures across a human “middle” macroscopic level, and all levels of nature. His arguments are rigorous, and he admits when he is being speculative.

Despite his move away from physicalism, his theories work with modern scientific concepts. He builds consciousness from the ground up, moving beyond physicalism, functionalism, and a host of other “isms” to introduce consciousness from first principles. His central tenets are independent of the mind-body problem, because they arise from analyzing causation itself.

His text can be difficult, and at times he opts for the philosopher’s terminology where a perfectly acceptable term may be substituted for the layman’s benefit. But Rosenberg does offer the more casual reader a guide through the chapters, allowing one to skip those chapters intended to elucidate certain ideas for readers familiar with the literature – primarily other analytical philosophy professors and graduate students. Within those chapters, and throughout the text, he offers another helping hand, providing an introduction and summary for each chapter, explaining what he will telling the reader, telling the reader, and then telling the reader what he just told her. His structure is welcome and his writing thorough. Rosenberg has advanced a bold new theory, though only an initial outline that calls for a sequel. Who will take it from here?