Updated: Oct 8
Authors: Arpan Dey and Sanchari Sen
The primary question we will attempt to investigate in this article is whether consciousness is a fundamental property of nature, or is it an emergent phenomenon. The nature of consciousness is shrouded in mystery. Although we understand a lot about how the world works from a third person perspective, we don’t understand the source of consciousness, even though everything we know is due to consciousness. Our conclusion is that consciousness is likely an emergent phenomenon. Consciousness emerges from physical matter (due to the arrangement of and interactions between physical matter), and ordered complexity is simply a fortunate product of random processes. We claim that defining consciousness as a fundamental property of the universe is not scientific. We also provide some evidence as to why it is likely that consciousness is emergent from physical matter.
In this article, we will also be addressing the question of whether we need fundamentally new kinds of laws to explain complex phenomena, or can extensions of the existing laws governing simpler phenomena successfully explain more complex phenomena. It is crucial to understand this question in order to obtain a better understanding of the way complexity arises from simplicity. This question is interdisciplinary in nature and would possibly have an effect on less fundamental sciences (like medical sciences), other than physics. The question involves chaos theory, emergence and many other concepts.
Weak and strong emergence
“I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.” - Issac Newton
First, what is emergence? When many simple parts are interacting, emergence refers to the origination of new properties of the system as a whole, which cannot be explained by studying the individual parts, or which do not arise from the properties of the individual parts. An example of emergence is wetness. The atoms or molecules that make up water are not individually wet, rather wetness emerges as a property of water as a whole. It’s the same thing with the brain. Each neuron is individually simple and carries out simple tasks. A single neuron is not conscious. At least, it does not have the properties that we have. However, the entire system the neurons have created together is way more complex. You can’t just sum up each neuron. If you do, you will not get consciousness. That needs something else. This something arises from the interaction between the parts of the system. Studying just the parts will tell you nothing about how the whole system affects an individual part, and how they interact with one another. So this is what we mean when we say consciousness is an emergent phenomenon.
Until recent insights into emergence, physicists have been studying the world from a reductionist point of view. According to reductionists, everything can be explained by breaking them into smaller and smaller pieces. But this may not be completely true. There are loads of phenomena in Nature which simply can't be explained from the reductionist's point of view. We need emergence for that. Zoom in, reductionism wins; zoom out, emergence wins (roughly speaking).
So the takeaway is that we can’t always explain the whole only by examining the parts. Now, the question arises whether that is due to our shortcomings or whether it is fundamentally impossible. This gives rise to two kinds of emergence: weak emergence and strong emergence. According to strong emergence, it is fundamentally impossible to explain complex phenomena just by studying the parts. In other words, we need fundamentally new kinds of laws to study complex phenomena. According to weak emergence, on the other hand, complex phenomena can be explained by the known laws or slight modifications or extensions of the known laws. We have not been able to completely understand complex phenomena like consciousness in terms of the known laws because of the magnitude of complexity. In theory, it is possible to understand consciousness just with the knowledge of the known laws that apply to less complex systems, but we don’t yet have the level of computational power required to break a system as complex as consciousness in terms of the underlying laws. Caltech physicist Sean Carroll explains the difference between weak emergence and strong emergence in his book The Big Picture:
[According to weak emergence] ...even if the emergent theory gives you new understanding and an enormous increase in practicality in terms of calculations, in principle you could put the microscopic theory on a computer and simulate it, thereby finding out exactly how the system would behave. In strong emergence—if such a thing actually exists—that wouldn’t be possible. When many parts come together to make a whole, in this view, not only should we be on the lookout for new knowledge in the form of better ways to describe the system, but we should contemplate new behavior. In strong emergence, the behavior of a system with many parts is not reducible to the aggregate behavior of all those parts, even in principle.
There are many physicists, including late UT Austin physicist Steven Weinberg and Columbia University physicist Brian Greene, who prefer reductionism over emergence, or at least, prefer the weak emergence argument over the strong emergence argument. Greene writes in his famous book The Elegant Universe:
Understanding the behavior of an electron or a quark is one thing; using this knowledge to understand the behavior of a tornado is quite another. On this point, most agree. But opinions diverge on whether the diverse and often unexpected phenomena that can occur in systems more complex than individual particles truly represent new physical principles at work, or whether the principles involved are derivative, relaying, albeit in a terribly complicated way, on the physical principles governing the enormously large number of elementary constituents. My own feeling is that they do not represent new and independent laws of physics. Although it would be hard to explain the properties of a tornado in terms of the physics of electrons and quarks, I see this as a matter of calculational impasse, not an indicator of the need for new physical laws. But again, there are some who disagree with this view.
Strong emergence demands a radical change in our worldview, and since we don’t understand the new laws yet, strong emergence is, in a certain sense, useless and with low predictive power. We should resort to such an explanation only if we are absolutely sure that reductionism or weak emergence can’t explain complex phenomena. Perhaps everything can, in theory, be explained in terms of the parts, but they depend on the parts in a very complicated way, as Greene argues. And there may, in reality, be no need for any fundamentally new set of laws to study complex phenomena. But since it is not practically possible for us to understand complex systems just by studying the parts, we should try to find some laws (not fundamentally new kinds of laws) which make the study of complex systems easier.
Consciousness: emergent or fundamental?
“There is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics.” - Richard Feynman
Before we start our discussion on consciousness, here’s a warning. If consciousness was simple enough to be understood, we wouldn’t be smart enough to understand it. So our efforts to understand what consciousness really is may be futile. It may never be possible for us to fully understand consciousness. Since we are bound by our consciousness, we can’t examine consciousness from a third-person perspective, and any theory of consciousness wouldn’t be properly testable or falsifiable, unless we are able to simulate consciousness artificially.
What can consciousness be? Well, we don’t know. But there are two major possibilities. Either it is an emergent property of matter. According to most neuroscientists, consciousness is an integrated whole that emerges from a particular arrangement of matter (and also interaction between matter). What’s the other possibility? Consciousness can be a fundamental phenomenon. Consciousness, the proponents of the second hypothesis claim, is a fundamental aspect of reality, rather than just a consequence of complex arrangement and interaction of matter. The idea that consciousness is fundamental and pervades the universe, for example, even atoms and electrons have some degree of consciousness, is called panpsychism. However, panpsychism is not a very good idea. Sean Carroll explains why:
We simply don’t gain anything by attributing the features of consciousness to individual particles. Doing so is not a useful way of talking about the world; it buys us no new insight or predictive power. All it does is add a layer of metaphysical complication onto a description that is already perfectly successful.
According to some of those who think consciousness is fundamental, consciousness is omnipresent (just like electromagnetic waves) and the brain can "pick up" this consciousness and transmit it, just like a radio picks up the radio signals. Sean Carroll explains this argument (and its weakness) nicely:
Perhaps the brain is like a radio receiver. Altering it or damaging it will change how it plays, but that doesn’t mean that the original signal is being created inside the radio itself... That idea doesn’t really hold up... Damaging a radio might hurt our reception, making it hard to pick up our favorite station. But it doesn’t turn that station from heavy-metal music into a smooth-jazz format. Damaging the brain, on the other hand, can change who a person is at a fundamental level.
There is no good evidence of consciousness being a fundamental phenomenon. The only logic somewhat supporting the fundamental consciousness argument is that consciousness is fundamentally different from matter and the physical world, so if consciousness is emergent, it would most likely require strong emergence to be true. However, this claim can be easily refuted. First, this argument assumes that it is likely that strong emergence is not true. But strong emergence can be true, and since consciousness is indeed different from physical matter, we think strong emergence would be a better candidate to explain consciousness than the fundamental consciousness hypothesis. And even the strong emergence hypothesis need not be true. Long long back, we thought of fire as something completely different from, say, wood. Liquid water is a new type of substance, and is different from ice. At that point of time, it would have seemed that fundamentally new kinds of laws are required to understand fire, which would be entirely different from the laws governing the behavior of wood. And the same goes for liquid water and ice. But today, we know that all of them are made of atoms, which are composed of the same fundamental particles: quarks and electrons. These particles are arranged differently in different substances, due to which fire is different from wood, or water from ice. But fundamentally, they are all made of the same kind of particles. Sean Carroll says in The Big Picture:
Over and over, something that we once thought of as a distinct kind of substance has been revealed to be a particular property of ordinary matter in motion. Life is no different.
So, although consciousness is extremely complex and sophisticated, there is no evidence on the basis of which we can say that we need fundamentally new kinds of laws to explain consciousness (strong emergence) or that consciousness is a fundamental property of the universe. It is perfectly possible that the complexity of consciousness emerges from many simple parts interacting in a very complicated manner, in which case consciousness would have a strong dependence on the parts it is made of. The only possible objection one might have to our argument is that fire, wood, ice and water are all physical objects that we can examine from a third-person perspective, while consciousness is something completely different. It is a qualitative property, and as already outlined above, we are dependent on our consciousness for all the conclusions we draw, so we can’t examine consciousness from a third person perspective, unless we are able to artificially simulate consciousness. However, it can be a pure coincidence that a particular arrangement of matter gives rise to sentience. Rubbing two pieces of wood doesn’t produce fire, but wood does have the capability of catching fire. Individual molecules do not sustain fire, even though a piece of wood does. Consciousness is different, and by coincidence, it happens to have the unique ability to comprehend its own source if a particular arrangement and interaction of matter is achieved. But that doesn’t change the fact that consciousness may still be subject to the known laws of physics.
Also, as already outlined above, if consciousness is a fundamental phenomenon, then why are our consciousnesses so dependent on our biology (more specifically on our brains)? A slight change in the structure of your brain can fundamentally change your personality, your very identity. And this is a proven fact in neuroscience. Keep in mind that just because emergence has not been able to satisfactorily explain consciousness till date, doesn't mean it is not possible. In the end, we think it is most likely that consciousness is emergent. There is definitely some evidence that consciousness is heavily dependent on the brain. We further claim that there's no feeling that can't be generated, at least in theory, by manipulating the levels of different chemicals in the brain. It's all happening inside the brain. We are aware of the fact that the brain is affected by a lot of factors (environmental, genetic etc.). But the point is, all these factors change the physical structure of the brain in some subtle way. We know it's not always possible to pin down these subtle changes, and often it is not a single change. So when we say there's no feeling that can't be generated by manipulating the levels of different chemicals in the brain, we don't mean to say that we can easily recreate all feelings artificially. All we are saying is, it's possible in theory.
Does free will exist?
Finally, we will briefly address the question of free will, in light of what we have discussed about emergence and consciousness. We have claimed that consciousness is emergent from physical matter, but what does this say about free will? Do we have free will? Or is it just an illusion, while in reality everything is completely deterministic? In his book Incognito: The Secret Lives Of The Brain, neuroscientist David Eagleman writes:
As far as we can tell, all activity in the brain is driven by other activity in the brain, in a vastly complex, interconnected network. For better or worse, this seems to leave no room for anything other than neural activity - that is, no room for a ghost in the machine… if free will is to have any effect on the actions of the body, it needs to influence the ongoing brain activity. And to do that, it needs to be physically connected to at least some of the neurons. But we don’t find any spot in the brain that is not itself driven by other parts of the network. Instead, every part of the brain is densely interconnected with - and driven by - other brain parts. And that suggests that no part is independent and therefore "free."
This is completely true. But we do not think this means there is no free will (the way most people define free will). Because free will can be an emergent property of human consciousness. Although the atoms and molecules that make up the brain do not possess the property of free will, it is entirely possible that the brain, considered in its entirety, has some form of free will. Free will can be a defining property of the emergent consciousness.
It should be noted that some physicists are suggesting that deep down, the universe is indeed deterministic and everything, in some sense and in theory, is predictable and predetermined. So, we can't completely rule out this possibility. Also, some people say that there is an element of uncertainty in quantum mechanics, and quantum mechanics is at the root of everything, so maybe free will does exist, and things are not predetermined. However, quantum mechanics has nothing to do with free will. In quantum mechanics, the outcomes of an experiment are random and not the same every time even if the initial conditions are not changed. This randomness is either an inherent property of the universe, or it arises due to our incomplete knowledge. This randomness does not mean that we can personally influence the outcomes of experiments. Yes, quantum mechanics does rule out determinism (by Heisenberg's uncertainty principle). But determinism ruled out does not mean free will verified.
Emergence is an ‘umbrella’ term that refers to the origination of new properties in complex systems that can’t be understood in terms of the simple parts that the system is made of. It’s an open question whether complex systems can, in theory, be studied using the known laws that govern simple objects (weak emergence), or whether we need to formulate fundamentally new kinds of laws to study complex systems.
We have then tried to investigate the nature of consciousness. Consciousness can either be an emergent property of matter, or it can be a fundamental property of the universe. We have argued why the consciousness-is-fundamental argument, although metaphysically appealing, is not a scientific argument. We have also outlined some evidence that doesn't support this hypothesis. Thus, with our arguments and evidence, we, standing at this point in the timeline of progress of science, claim that consciousness is an emergent property of nature and not a fundamental one.
 Pines, David. Santa Fe Institute. “Emergence: A unifying theme for 21st century science.”
URL = <https://medium.com/sfi-30-foundations-frontiers/emergence-a-unifying-theme-for-21st-century-science-4324ac0f951e/>
 O’Connor, Timothy. "Emergent Properties". The Stanford Encyclopedia of Philosophy (Winter 2021 Edition). Edward N. Zalta (ed.). URL = <https://plato.stanford.edu/archives/win2021/entries/properties-emergent/>.
 Carroll, Sean. “The Big Picture: On the Origins of Life, Meaning, and the Universe Itself.” Dutton.
 Greene, Brian. “The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory.” W. W. Norton.
 Eagleman, David. “Incognito: The Secret Lives of the Brain.” Canongate.