Consciousness experiences can be found in unlikely ways, such as all creatures, big and small, and possibly also in brute matter itself.
What has the delectable taste of a favourite food in common with the sharp sting of an infected tooth, the fullness after a heavy meal, the slow passage of time while waiting, the willing of a deliberate act, and the mixture of vitality tinged with anxiety just before a competitive event in common?
Both of these are distinct experiences. What unites them is that they are all subjective states that are consciously felt. Accounting for the essence of consciousness is difficult, with many saying that it cannot be described at all, despite the fact that doing so is easy.
Here’s what I mean: consciousness is memory.
That is everything there is to it. Consciousness includes all experiences, from the most mundane to the most profound. Some people differentiate knowledge from consciousness; I don’t think this distinction is useful, so I use the terms interchangeably. I often do not differentiate between feeling and experience, despite the fact that in everyday language, the feeling is reserved for intense emotions such as being angry or in love. Any feeling, in my opinion, is an experience. Consciousness, then, is lived experience when taken collectively. It is the sensation of being alive.
But who else, except me, has had similar experiences? I assume you do because you are so close to me. The same logic holds true for other citizens. With the exception of the single solipsist, this is uncontroversial. But how prevalent is consciousness in the world as a whole? As animals grow more foreign to us, it becomes more difficult to deduce how far consciousness spreads its dominion within the tree of life.
One line of reasoning follows the principles of integrated information theory (IIT) all the way to their logical conclusion. It argues that all species, including Paramecium and other single-cell life forms, have some degree of experience. Indeed, according to IIT, which seeks to specifically describe both the quality and quantity of any single conscious experience, experience may not even be limited to biological beings but may extend to non-evolved physical structures previously thought to be mindless — a satisfying and rational conclusion about the universe’s makeup.
How Popular Is Consciousness on the Tree of Life?
The tree of life metaphor is widely used to depict the evolutionary relationship between bacteria, fungi, plants, and animals. All living species, whether fly, mouse, or human, live on the tree’s periphery, equally adapted to their respective ecological niches.
Any living organism descended from the last universal common ancestor (abbreviated to a charming LUCA) of planetary life in an unbroken lineage. This hypothetical species existed 3.5 billion years ago, smack dab in the middle of the tree-of-life mandala. Evolution describes not just the composition of our bodies, but also the composition of our minds, which do not receive a special dispensation.
Given the similarities between Homo sapiens and other mammals at the behavioural, physiological, anatomical, developmental, and genetic stages, I have no reason to suspect that we all experience the sounds and sights, the pains and pleasures of life, but not generally as richly as we do. We all aspire to eat and drink, procreate, and escape injury and death; we bask in the sun’s warm rays, seek the company of conspecifics, fear predators, sleep, and dream.
Although mammalian consciousness is dependent on a functional six-layered neocortex, animals without a neocortex do feel. Again, the similarities in the structure, dynamics, and genetic specification of all tetrapod nervous systems — mammals, amphibians, birds (especially ravens, crows, magpies, parrots), and reptiles — lead me to believe that they, too, experience the world. Other species with backbones, such as fish, maybe inferred in a similar way.
But why be a chauvinist of vertebrates? The tree of life is inhabited by a swarm of invertebrates that move about, sense their surroundings, learn from previous experience, show all the trappings of emotions, and interact with one another — insects, crabs, worms, octopuses, and so on. We can scoff at the idea that tiny buzzing flies or diaphanous pulsating jellyfish, both of which have such alien forms, may have feelings.
Honey bees, on the other hand, can identify faces, communicate the location and quality of food sources to their sisters through the waggle dance, and traverse complex mazes using cues stored in short-term memory. A scent blown into a hive may cause the bees to return to the location where they first encountered the odour, a form of associative memory. Bees have collaborative decision-making abilities that would put every university faculty committee to shame. This “wisdom of the crowd” phenomenon has been studied during swarming, which occurs when a queen and thousands of her workers break off from the main colony and select a new hive that must meet several demands essential to group survival (think of that when you go house hunting). Bumblebees can also learn to use resources by learning how other bees use them.
In an 1881 book on earthworms, Charles Darwin wished to learn “how much the worms behaved consciously and how much mental strength they showed.” Darwin concluded from observing their feeding habits that there was no absolute threshold between complex and simple animals that attributed higher mental powers to one but not the other. Nobody has found a Rubicon that divides sentient from nonsentient beings.
Of course, the complexity and variety of animal consciousness will decline as their nervous systems become simpler and more basic, ultimately transforming into a loosely structured neural net. The dynamics of the organisms’ interactions will slow down as the speed of the underlying assemblies slows.
Is it really appropriate to have a nervous system to have any experience? We have no idea. It has been claimed that trees, members of the plant kingdom, can interact with one another in unexpected ways and that they can adapt and learn. Of course, none of this is impossible if you have no previous experience. As a result, I would describe the facts as intriguing but preliminary. How far down the difficulty ladder, rung by rung, can we go until there isn’t even a glimmer of awareness? Again, we have no idea. We’ve crossed the limits of abduction based on our resemblance to the only subject with whom we have direct contact — ourselves.
The Universe’s Consciousness
IIT provides a new line of thinking. The principle specifically addresses the question of who can have an experience: anything with a non-zero maximum of integrated knowledge is considered a Whole, as is anything with inherent causal forces. This Whole’s experience is determined by its maximally irreducible cause-effect structure. Its integrated knowledge determines how long it exists.
In other words, the theory does not mean that there is any mystical level above which experience is enabled. Instead, the degree of consciousness is expressed as, or phi. If phi is zero, the system does not exist for itself; everything with a max greater than zero exists for itself, has an inner vision, and some degree of irreducibility — the higher this number, the more aware the system is. As a result, there are a lot of Wholes out there.
People and other mammals with the neocortex, which we scientifically know to be the substrate of experience, are certainly included. Fish, birds, reptiles, and amphibians, on the other hand, have a telencephalon — the largest and most evolved portion of the brain — that is evolutionarily similar to the mammalian cortex. Given the associated circuit complexity, the telencephalon’s intrinsic causal power is likely to be high.
When we consider the neural circuitry of species so different from us, such as the honey bee, we are faced with immense and untamed neuronal complexity — approximately one million neurons within a volume the size of a grain of quinoa, a circuit density ten times greater than that of our neocortex, of which we are so proud. In addition, unlike our cerebellum, the mushroom-shaped body of the bee is heavily recurrently related. This tiny brain is likely to form a maximally irreducible cause-effect structure.
Integrated information is about intrinsic cause-effect power rather than input-output processing, function, or cognition. After dispelling the myth that consciousness is inextricably connected to intelligence, the theory is free to throw off the constraints of nervous systems and seek inherent causal influence in processes that do not compute in any traditional sense.
One example is single-cell organisms like Paramecium, the animalcule discovered by early microscopists in the late 17th century. Protozoa use whiplash movements of tiny hairs to propel themselves through water, avoid obstacles, sense food, and display adaptive responses. We don’t think of them as sentient because of their small size and unusual environments. They do, however, bring our conclusions into question. H. S. Jennings, an early student of such microorganisms, put it succinctly:
The much smaller Escherichia coli bacteria, which can cause food poisoning, are among the best-studied of all species. Within their defensive cell wall, their rod-shaped bodies, about the size of a synapse, house several million proteins. No one has completely modelled such enormous complexity. Given its byzantine complexity, a bacterium’s causal power upon itself is unlikely to be zero. According to IIT, it most definitely sounds like a bacterium. It won’t be disturbed by its pear-shaped body; no one will ever research a microorganism’s psychology. However, there will be a faint glow of knowledge. This glow will fade as the bacterium disintegrates into its constituent organelles.
Let us go even smaller in size, from biology to the simpler worlds of chemistry and physics, and calculate the inherent causal force of a protein molecule, an atomic nucleus, or even a single proton. Protons and neutrons are made up of three quarks with a fractional electrical charge, according to the standard model of physics. Quarks are seldom observed on their own. As a consequence, it is conceivable that atoms form an irreducible Whole, a sliver of “enminded” matter. How does it feel to be a single atom in comparison to the approximately 1026 atoms that comprise the human brain? Given that its integrated knowledge is most likely barely above zero, is it just a short bagatelle, a this-rather-than-not-this?
Consider an instructive example to help you wrap your head around this possibility that offends Western cultural sensibilities. The cosmic microwave background radiation, the afterglow of the Big Bang, determines the average temperature of the universe. At an average temperature of 2.73° above absolute zero, it pervades space uniformly. This is completely freezing, hundreds of degrees below the freezing point at which terrestrial organisms will live. However, the fact that the temperature is not zero means that there is a correspondingly limited amount of heat in deep space. This, of course, means a correspondingly insignificant level of experience.
To the degree that I am debating the mental in relation to single-cell species, let alone atoms, I have entered the domain of pure speculation, which I have been educated as a scientist to avoid my entire life. However, three factors compel me to throw caution to the wind.
To begin, these concepts are clear extensions of IIT — which was designed to describe human-level consciousness — to radically different aspects of physical life. Predicting phenomena by extrapolating to situations well beyond the theory’s original remit is one of the hallmarks of a strong scientific theory. There are numerous precedents, such as the fact that the passing of time depends on how quickly you fly, that spacetime will break down at singularities known as black holes, that humans, butterflies, vegetables, and the bacteria in your gut all use the same mechanism to store and copy their genetic material, and so on.
Second, I admire this prediction’s elegance and beauty. (Yes, I am well aware that the last 40 years of theoretical physics have presented sufficient evidence that pursuing elegant theories has yielded no new, empirically testable evidence explaining the actual universe we live in.) The mental does not emerge suddenly from the physical. Nature, as Leibniz put it, “facit saltus,” or “does not make sudden leaps” (Leibniz was, after all, the co-inventor of infinitesimal calculus). The absence of discontinuities is also a central tenet of Darwinian theory.
The problem of how the mind arises from matter is eliminated by intrinsic causal force. According to IIT, it has always been there.
Third, IIT’s prediction that the mind is far more common than previously believed resonates with an ancient school of thought known as panpsychism.
Many, but not all, things are remembered.
The idea that soul (psyche) is in all (pan) or is ubiquitous; not only in animals and plants, but all the way down to the ultimate constituents of matter — atoms, fields, strings, or whatever — is shared by panpsychism in its various manifestations. Panpsychism holds that every physical system is either conscious, composed of conscious components, or is a part of a larger conscious whole.
Some of the West’s finest minds have proposed that matter and soul are the same things. This includes Thales and Anaxagoras, two pre-Socratic philosophers from ancient Greece. Plato, the Renaissance cosmologist Giordano Bruno (burned at the stake in 1600), Arthur Schopenhauer, and the 20th-century palaeontologist and Jesuit Teilhard de Chardin all advocated such theories (whose books, defending evolutionary views on consciousness, were banned by his church until his death).
Many scientists and mathematicians with well-articulated panpsychism views stand out. The first and foremost is, of course, Leibniz. However, we can also include the three psychologists and psychophysicists — Gustav Fechner, Wilhelm Wundt, and William James — as well as the astronomers and mathematicians Arthur Eddington, Alfred North Whitehead, and Bertrand Russell. With the modern devaluation of metaphysics and the emergence of analytic philosophy, the twentieth century completely evicted the mental, not just from most academic departments but also from the world at large. However, this denial of consciousness is now known as the “Great Silliness,” and panpsychism is experiencing a resurgence in academia.
The debate on what happens is divided into two camps: materialism and idealism. Materialism, and its modern counterpart, physicalism, have gained tremendously from Galileo Galilei’s pragmatic stance of detaching the mind from the objects under examination in order to explain and measure existence from the viewpoint of an outside observer. It has done so at the expense of ignoring the most important element of reality: knowledge. Erwin Schrödinger, one of the pioneers of quantum mechanics and the name of the most famous equation, explained it succinctly:
Idealism, on the other hand, is thought to be a figment of the imagination and thus has little productive to say about the real world. Cartesian dualism embraces both in a troubled marriage in which the two spouses live parallel lives without communicating to each other (this is the interaction problem: how does matter interact with the ephemeral mind?). Analytic, logical-positivist philosophy, like a thwarted lover, rejects the validity and, in its most severe form, even the presence of one partner in the mental-physical relationship. It does so in order to hide its inability to deal with emotions.
Panpsychism is a unified theory. There is only one material, rather than two. This elegantly avoids the need to justify how the mind arises from the physical and vice versa. Both exist side by side.
The beauty of panpsychism, on the other hand, is sterile. Apart from suggesting that something has both intrinsic and extrinsic dimensions, it says nothing informative about the relationship between the two. Where is the experiential distinction between a single atom zipping around in outer space, a hundred trillion trillion trillion atoms that make up a human brain, and an uncountable number of atoms that make up a sandy beach? Panpsychism is deafeningly silent on such topics.
IIT and panpsychism share many insights, beginning with the basic idea that consciousness is an essential, fundamental part of life. Both approaches contend that consciousness exists to varying degrees in the animal kingdom.
All else being equal, integrated knowledge, and thus the richness of experience, increases as the complexity of the associated nervous system increases, though the cerebellum demonstrates the sheer number of neurons is not a guarantee. Through alertness and sleep, awareness waxes and wanes during the day. It develops over time, becoming richer as we move from foetus to adolescent to adult with a fully developed cortex. It develops as we become acquainted with romantic and sexual relationships, with alcohol and drugs, and as we cultivate enthusiasm for games, sports, books, and art, and it eventually fades as our ageing brains wear out.
Most notably, unlike panpsychism, IIT is a scientific theory. IIT predicts the relationship between neural circuits and the quantity and quality of experience, how to construct an instrument to detect experience, pure experience (consciousness without any content) and how to enlarge consciousness through brain-bridging, why certain parts of the brain have it and others do not (the posterior cortex versus the cerebellum), and why brains with human-level consciousness evolved.
When I lecture on these topics, I frequently get the you’ve-got-to-be-kidding look. This will pass until I clarify how neither panpsychism nor IIT asserts that elementary particles have thoughts or other cognitive processes. Panpsychism, on the other hand, has an Achilles’ heel: the combination dilemma, which IIT has squarely solved.
On the Impossibility of Group Mind, or Why Your Neurons Are Not Conscious
William James gave a memorable example of the combination problem in the foundational text of American psychology, “The Principles of Psychology” (1890):
Experiences do not merge to form larger, superordinate ones. Closely communicating lovers, musicians, athletes, soldiers, and so on do not create a collective mind with experiences that outweigh those of the individuals who compose the group. According to John Searle:
Panpsychism has not offered a clear explanation for why this is the case. However, IIT does. According to IIT, there are only maxima of integrated knowledge. This is a function of the exclusion axiom: every conscious perception has limits. Certain elements of experience are allowed, although a large universe of potential emotions is forbidden.
Consider the picture above, in which I am looking at my dog Ruby and having a clear visual experience, which has a maximally irreducible cause-effect structure. It is made up of the underlying physical substrate, the Whole, and a specific neural correlate of consciousness within my posterior cortex’s hot zone. However, the experience is not the same as the Whole. My brain is not my experience.
This Whole has distinct boundaries; a specific neuron is either a part of it or not. Even if this neuron provides some synaptic input to the Whole, the above is valid. The Whole is defined by a maximum of integrated information, with the maximum being measured across all spatiotemporal scales and levels of granularity, such as molecules, proteins, subcellular organelles, single neurons, large ensembles of them, the environment with which the brain interacts, and so on.
My conscious perception is created by the irreducible Whole, not by the underlying neurons. So not only is my perception not my brain, but it is most emphatically not my individual neurons. While a handful of cultured neurons in a dish may have a tiny amount of experience and form a mini-mind, the hundreds of millions of neurons that comprise my posterior cortex do not represent a series of millions of mini-minds. There is just one mind, my mind, which is made up of the Whole in my head.
Other Wholes in my brain or body can exist as long as they do not share elements with the posterior hot zone Whole. As a result, it may feel like something to be my liver, but given the very minimal interactions between liver cells, I doubt it feels like anything.
The exclusion theory explains why consciousness fades during slow sleep. Delta waves dominate the EEG at this time, and cortical neurons have normal hyperpolarized down-states in which they are silent, interspersed with active up-states in which neurons are more depolarized. These on- and off-periods are organised regionally. As a result, the cortical Whole disintegrates, splintering into small cliques of interacting neurons. Each one is likely to have only a speck of integrated knowledge. In deep sleep, “my” consciousness effectively vanishes, replaced by a plethora of tiny Wholes, none of which are recalled upon waking.
Read more: Are You Your Own connectome?
The exclusion postulate also determines if an aggregate of conscious entities exists as conscious entities, such as ants in a colony, cells in a tree, bees in a hive, starlings in a murmuring flock, an octopus with eight semiautonomous arms, or hundreds of Chinese dancers and musicians during the choreographed opening ceremony of the 2008 Olympic Games in Beijing. A herd of buffalo or a crowd can behave as if they have “one mind,” but this is just a figure of speech unless there is a phenomenal force that feels above and above the perceptions of the individuals that make up the party. According to IIT, this would necessitate the extinction of the individual Wholes, as the integrated knowledge for each of them is less than the Whole’s maximum. Everyone in the crowd must surrender their individual consciousness to the group’s mind, just like the Borg hive mind in the “Star Trek” universe.
The exclusion postulate of IIT does not allow for the presence of both entity and group mind at the same time. Thus, the Anima Mundi, or world spirit, is ruled out because it requires the extinguishment of all living beings’ minds in favour of the all-encompassing soul. Similarly, being one of the three hundred million residents of the United States of America does not feel like anything. As an entity, the United States holds major extrinsic causal powers, such as the right to kill its people or launch a war. However, the country lacks maximally irreducible inherent cause-effect force. Countries, companies, and other collective agents function as formidable military, diplomatic, financial, legal, and cultural bodies. They are aggregates, but they are not Wholes. They lack phenomenal truth as well as an inherent causal force.
Thus, single cells may have some inherent life, but this does not generally extend to the microbiome or trees, according to IIT. Animals and humans live in their own right, but herds and crowds do not. Atoms may exist in their own right, but spoons, tables, dunes, or the universe as a whole do not.
Every Whole, according to IIT, has two sides: an exterior aspect that is known to the world and communicates with other things, including other Wholes, and an interior aspect that is what it feels like, its experience. It is a lonely life, with no direct access to the interiors of other Wholes. Two or more Wholes may combine to form a larger Whole, but at the risk of losing their previous identities.
Finally, panpsychism has little to say about consciousness in computers that is understandable. However, IIT does. Conventional digital computers, which are made up of circuit components with sparse connectivity and no overlap between their inputs and outputs, do not form a Whole. Computers have only a small amount of extremely fragmented intrinsic cause-effect power, regardless of the programme they are running or their computational power. Androids, if their physical circuitry is anything like today’s CPUs, would be unable to picture electric sheep. Of course, it is possible to create computational machinery that closely resembles neuronal architectures. Such neuromorphic engineering objects could contain a large amount of integrated data. Still, we are a long way from those.
IIT can be viewed as an extension of physics to the most basic element of our lives: consciousness. The interaction of objects with each other, as determined by extrinsic causal forces, is the topic of textbook physics. My and your perceptions are how irreducible inherent causal forces in brains feel on the inside.
IIT provides a principled, consistent, testable, and elegant account of the relationship between these two apparently separate realms of life — physical and mental — that is based on extrinsic and intrinsic causal forces. The causal power of two kinds is all that is needed to understand anything in the universe. These abilities are the fundamental manifestations of existence.
More experimental work would be needed to validate, alter, or even reject these viewpoints. If history is any guide, future discoveries in laboratories and hospitals, or maybe even on other planets, will astound us.
Our journey has come to an end. The world shows itself to be an ordered place when illuminated by the light of our pole star, consciousness. It is much more enlightened than modernity, blinded by its technical superiority over the natural world, beliefs. It is a more conventional viewpoint that recognises and fears the natural environment.
Experience can be found in unlikely ways, such as all creatures, big and small, and possibly also in brute matter itself. Except when they speak in tongues, automated machines running software do not have consciousness. As machines become more powerful, they will trade in phoney consciousness, which will possibly deceive the majority of people. But, precisely because of the imminent conflict between natural, developed intelligence and artificial, engineered intelligence, it is important to claim the centrality of feeling to a lived life.