Chapter 15 (Consciousness as an Emergent Property)

Emergent properties

An emergent property is a characteristic of a whole system that arises from the organization and interaction of its parts, though it is not present in those parts alone. Philosophers typically describe such properties as combining dependence on lower-level components with some degree of autonomy at the higher level: a new property appears when simpler parts interact, even though no individual part possesses that property. Individual molecules of protein, nucleic acid, or lipid are not alive, but when they organize and interact, a cell forms. Life emerges when cells, tissues, and organs organize into an organism. In a colony of ants, no single ant comprehends the colony as a whole, yet the colony can build nests, allocate labor, defend territory, and adapt to disturbances; this coordination is an emergent property. Flocks of birds and schools of fish have no central leader yet coordinated group motion still appears. Traffic jams emerge not from any single car but from the stop-and-go patterns of many cars interacting on a crowded highway.

Reductionism

Reductionism is, in a sense, the opposite of the emergent-property view. It holds that a complex system is nothing more than the sum of its parts and that, in principle, any system can be fully explained by analyzing those parts in isolation together with the laws governing their interaction. Once those laws are understood, it should be possible to predict any emergent property from the parts alone. Reductionism emphasizes bottom-up explainability, whereas emergence holds that genuinely new higher-level properties can arise—properties that depend on the parts but cannot usefully be understood or predicted by examining those parts in isolation.

Downward causation 

Downward causation is the concept that higher-level, macro-scale properties, structures, or systems can exert a causal influence or constraint on their lower-level, micro-scale parts. It challenges strict reductionism and that all causation moves from bottom up. A classic example of downward causation is a chimpanzee's social hierarchy influencing its serotonin levels. The chimpanzee’s status or rank inside the social group is the high-level, systemic property. The biological activity of serotonin production is a lower-level physical/chemical property. The downward causal effect is that the macro-level social standing acts down upon and alters the micro-level neurotransmitter concentration inside the animal's body, rather than the chemistry solely driving the behavior from the bottom up. Other examples include laws or cultural norms (macro-level social structures) constraining and shaping the daily actions of an individual person (micro-level behavior). Anxiety or stress (a macro-level emotional state) affecting blood pressure, skin conditions, or immune responses (micro-level biological changes). A person's conscious decision to move their arm (a high-level mental state) causing groups of motor neurons to fire and muscles to contract (low-level physiological events). 

Completeness of the physical

 The completeness of the physical (also sometimes called " closure of the physical” or the “causal closure of physics”) claims that when you trace the causal history of any physical event, you never need to leave the physical domain — the physical universe contains within itself the resources for a full causal explanation of any of its caused elements, and in that sense is complete or closed. Or as Kim, quoted in Wikipedia, (Causal closure; https://en.wikipedia.org/wiki/Causal_closure) puts it "if we trace the causal ancestry of a physical event we need never go outside the physical domain." The formulation, however, has different degrees of completeness. In its most complete form (Kim’s version) every physical effect has a sufficient physical cause, i.e. nothing non-physical is ever needed ruling out any non-physical contribution. Weaker versions leave room for additional non-physical causes alongside physical ones and for physical causes to have non-physical effects.

Causal closure arguments do not require determinism. Closure is about the domain of causes, not about whether causation is deterministic. Probabilistic physical explanations are still allowed. Quantum indeterminacy does not open a door since the probabilities are fixed by the physical state. Causal closure does not depend on the laws of conservation of energy which have been questioned by physicists. Causal closure and physicalism are related but not identical. Physicalism is an ontological claim that only material or physical things exist; nothing non-physical exists. Causal closure is a claim about causes—asserting that it is never necessary to step outside the physical domain to find an event’s cause.

Forces as emergent properties?

Modern physics understands the world in terms of fundamental particles, the building blocks of all matter and forces. Western science recognizes four forces—gravity, electromagnetism, and the strong and weak nuclear forces. Physicists were compelled to postulate these forces to explain the behavior of matter, and they are emergent properties in the sense that their effects become apparent only when systems grow complex enough for those effects to be observed. Gravity, for example, is an extraordinarily weak force at the subatomic level, yet its power becomes apparent in apples falling to the ground and in planets moving in their orbits. Electromagnetism was needed to explain the behavior of charged particles; the strong nuclear force, to explain the atomic nucleus and how positively charged protons remain tightly packed; and the weak nuclear force, because radioactive decay had no explanation within the forces then known. Dark energy, which accounts for roughly 73% of the energy in the universe, was only "discovered" in 1998, its existence inferred to explain what causes the universe's expansion to accelerate rather than decelerate. Physicists currently understand these forces as acting through force-carrying particles—gluons for the strong nuclear force, bosons for the weak nuclear force, gravitons for gravity. I'm calling them emergent because we only see them in a context, but physicists, I think generally, do not see these forces as emergent; they see them as present at all levels and all times, with their effects becoming apparent to us only at higher levels of complexity.

Consciousness as a substance?

The word "substance" can carry different meanings. Here, let us take a substance to mean an actual "thing," like a piece of matter, while a property is an observable or measurable characteristic describing what that substance is like. In science, a substance is the fundamental material composition of an object (water, gold, or table sugar, for instance); it answers the question "What is this thing?" A property is an attribute or feature belonging to a substance, such as its color, melting point, density, or flammability. Substances and properties stand in a relation: properties do not exist on their own but require substances. In philosophy, a substance is an independent entity, or bearer of attributes, that can exist on its own (like a physical body or a separate mind), whereas a property is a dependent characteristic or attribute had by a substance.

Chapter 14 considered the appearance of consciousness across evolution. It began with the Merriam-Webster online definition of consciousness as "the quality or state of being aware especially of something within oneself" or "the state or fact of being conscious of an external object, state, or fact," or again "the state of being characterized by sensation, emotion, volition, and thought." We also considered the related terms sentient, thought, thinking, and intelligence. On these definitions, some kind of nervous system is generally thought necessary for consciousness to be present. We saw, however, examples such as slime molds that seem to exhibit a type of intelligence even though they have nothing resembling a nervous system.

Throughout Chapter 14 we treated consciousness as a property or attribute of a system, describing a state or capacity of an organism—wakefulness, sentience, self-awareness—as in "he lost consciousness" or "he was not conscious of the danger he was in." Consciousness can, however, carry a second meaning, in which it is regarded as a constituent of reality. In this sense consciousness, sometimes written with a capital "C," can be considered a fundamental feature of reality: a substance, a field, or a force—something like an electric field, a thing that has properties rather than being a property of other things. This is a different kind of claim, an ontological rather than a descriptive one, and it is more akin to terms such as spirit or vital force.

There is a third context in which consciousness may be considered a state: I recognize that I am a consciousness in a body, in a transient state of being alive. This resembles the Buddhist notion of the person as a transient aggregate of properties, with no permanent state underlying it.

Did consciousness emerge in the universe?

Pierre Teilhard de Chardin (1881-1955) was a French Jesuit priest, paleontologist and philosopher. He proposed an evolutionary spiritual vision of the cosmos in which the universe was evolving in complexity and consciousness towards a spiritual unity (a monism), which he called the "Omega Point". He believed that matter and spirit are interconnected and that evolution is a process whereby the universe becomes more complex and conscious. He argued that even the most primitive matter has an inner embryo of consciousness, which became self-aware in the evolution of human beings. As matter evolved toward greater structural complexity, this in turn resulted in consciousness. He thought the next stage of evolution would be toward what he called the "noosphere," a sphere of pure human thought comprising collective human consciousness. The Omega Point was the irresistible attractor and final outcome of this evolutionary process seen as an ultimate center of personality and consciousness where while preserving individual personalities, all individual human consciousness and the entire cosmos would converge in a mystical union into one.

Importantly in Teilhard’s conceptualization he saw the attractor as an active agent exerting a force that was pulling the universe towards a new state. In religious terms he saw this as a divine process with the Omega Point, identified with Christ, in which Christ is the driving force and organizing principle within the universe, actively driving the universe toward a spiritual union with God. His conceptualization had a teleological element to it; God was consciously driving the universe towards this end. He was a monist in viewing, matter and consciousness as not two substances or two different modes of existence, but two aspects of the same cosmic stuff.

Teilhard's contribution was not in truth the emergence claim, which in the West had been suggested from 1843 onward, but his arrangement of it into a story line from particles to biosphere to thought to God. Indeed, the claim that consciousness emerges from matter is not one position but three, organized around the question of does anything new physically appear. All else in the debate follows—including whether physics is casually closed and whether evolution has a destination.

The first argument sometimes called weak emergence states that higher-level features like consciousness are real but nothing physically new is added. Consciousness forms from physical elements already there. Closure is complete. Whether considered a state or a substance, consciousness is real and material, but physics can explain it. This is the position of a mainstream physicalist. J.S. Mill (1806-1873) and G.M. Lewes (1817-1878) can be seen as proponents of the first position. Terrance Deacon's (born 1950) "Incomplete Nature: How Mind Emerged from Matter" can be seen as a more modern version of this argument.

The second position sometimes known as strong emergence postulates that genuinely novel causal powers or forces appear at higher levels. Inconsistent with physicalism, it denies causal closure of physics and claims that genuinely novel forces appear at higher levels. Kim's exclusion argument takes aim at exactly at this position. Roger Sperry (1964-1993) and William Hasker (born 1935) can be seen as two proponents of the second argument.

The third position is that emergence is not just real but directed; matter is heading towards mind and mind towards something further in the future. Bedsides Teilhard, Henri Bergson (1907) can be seen as a proponent of this position.  Bergson’s “Creative Evolution” proposed an élan vital —a creative force working against inert matter not out of it. He saw evolution as creative not reductionist and mechanistic. This last position amounts to teleological emergence. It has cultural appeal but has lost the scientific argument. Physicists have mostly ignored it. Evolutionary biology rejects the built-in directionality..

Consciousness emerging

In chapter 14, we traced the evolution of consciousness the property or state as it developed across evolution. Indeed, consciousness continually remerges in the birth and growth of all living creatures that have the property of consciousness.  In that context, consciousness, the property is clearly emergent. It seems fair to say that when consciousness the property is present, Consciousness the substance, if it exists is present. However, does it work the other way around? Is it possible to have Consciousness the substance present, without the property of consciousness? In the philosophy of mind, substance dualism claims the mind and body are two separate kinds of substances, whereas property dualism claims there is only one physical substance (the brain) but it has both physical and mental properties. Property dualism is thus really a form of monism. There is only one but it looks like there are two. Where consciousness the substance belongs will require further exploration.