Emergence 5 – Strong Emergence and Downward Causation

               I have been exploring the scientific and philosophical concept of “emergence” (starting <here>).  Summarizing my previous entries in a single sentence:  my contention is that when you really analyze what emergence means when it is used as an explanation for consciousness, it is actually just another word for consciousness, and thus explains nothing.  

              Previously we discussed the concepts of “weak emergence” and “strong emergence”.  “Weak emergence” refers to emergent properties that are, at least in principle, explainable by the underlying physical properties.  In my opinion, weak emergence is ubiquitous, but has nothing to do with human consciousness.  In “strong emergence”, the connection between the higher-level events and the underlying physics becomes strained and broken in some manner.  I previously made the claim that it is very misleading to use the terms “weak emergence” and “strong emergence” because it makes it sound like the two terms are related, whereas, in reality, the two terms have almost nothing in common.  I suggested that a better term for “strong emergence” was “beyond physics” (i.e. “metaphysics”) or, even more simply, “consciousness.” 

              I said there were two features that tend to get combined under the heading of “strong emergence”, and that these two features are also so different from one another that they should each be given a separate descriptive term – i.e. they shouldn’t be combined under a single term.  The first feature of strong emergence was that the emergent property cannot, even in principle, be explained by the underlying physics of the situation.  You can read that entry here.  In today's entry, it is now time to address the second feature of strong emergence.

              The second major feature often lumped under the term “strong emergence” is the idea that, in some manner (often undefined) the emergent property can exert a top-down effect on the underlying physics or the underlying fundamental particles.  This is often referred to as “downward causation.”[1] 

              It’s hard to come up with an example of downward causation, so I’ll start with something hypothetical.  Let’s say that the flow of water molecules could be described as an emergent property called “river”, and then “river”, by virtue of where it decides to flow, exerted an influence on the water molecules to make the water molecules move where the river “wanted” them go.  That would be an example of “downward causation”.  The emergent property of “river” would be obeying its own laws that are outside, or in addition to, the fundamental laws that govern the interactions of the water molecules.  In this case, if you applied the fundamental laws to all of your water molecules, you would find that they are not moving exactly as you predict because the river is exerting an outside influence on one or more of the water molecules (that influence is, in this hypothetical example, not itself included in the fundamental physics of the situation).  Now, that is not how it works with water molecules and rivers.  Rivers are defined by the collection and interaction of the water molecules that make it up, as well as the environment surrounding the water molecules (i.e. the molecules that make up the river bank and river bed).  There is no separate, distinct “intentional river flow” that exists apart from the fundamental principles of physics for the entire system.  Thus, in reality, river flow is actually an example of weak emergence, not strong emergence.

              You may wonder “well, what example could there possibly be of strong emergence?”  That is a valid question!  Frequently, people devolve to using consciousness as the primary (or only?) example of strong emergence, something I find pretty circular. 

              Sometimes people come up with examples of “emergence”, where, if you listen closely, you will realize that there is a human involved in their example somewhere along the way.  A conscious human.  Let me give you a very common example of this:  traffic flow as an emergent property of multiple cars driving on a road.  Traffic patterns arise (emerge) from these cars as they drive, patterns such as the stop-and-go waves that we get stuck in on our way to work.  You can’t just examine a single car driving along and predict the various kinds of traffic patterns that will emerge from a whole group of cars on the road.  Thus, traffic patterns are considered an emergent property.  Philosophers will then say “just like complex traffic patterns emerge from a group of single cars driving on the road, so analogously, consciousness could arise from a group of neurons acting in a complex network.”  There are two important problems with this.  First, traffic patterns are weak emergence and, in fact, can typically be simulated with software.  The comparison between traffic and consciousness is based on an implied link between the weak emergence of traffic patterns and the strong emergence of consciousness.  What is that link?  They both have the word “emergent” in them – but otherwise they are unrelated concepts!  That is why I think it is wrong to use the term “strong emergence”, as I pointed out in my previous entry on this topic <here>.

              However, there is another funny thing about calling traffic an emergent property and then using it as an analogy to explain how consciousness arises from the brain.  Cars don’t do anything unless they are driven – driven by a human being – a conscious human being.  Cars don’t make decisions; the human drivers do.  Presumably, those humans utilize their conscious brain to make those decisions and initiate the actions they make as drivers.  This is like defining a word by using the same word in the definition.  In some real way, traffic flow is just the action of a lot of conscious human drivers making their conscious decisions.  To then describe traffic flow as an emergent property and therefore analogous to consciousness seems very circular to me.

              Sometimes examples of strong emergence are open systems rather than closed systems.  Open systems are those where there are “outside influences” on how the system behaves.  These outside influences then can become the top-down influence of strong emergence.  For example, life itself is sometimes put forward as an example of strong emergence, because it emerges from the underlying biochemical activity, but life also seems to exert a top-down influence on what the living thing does.  Living things do purposeful activities but the underlying chemicals and reactions do not have anything like “purpose” as part of their properties.  But living things are not closed systems.  They must constantly ingest some kind of energy to keep going and stay living.  They are also living within an external environment.  To me, this seems analogous to the “water and river” example I gave earlier.  The banks of the river are the environment that the water finds itself in, and the banks exert an influence on where the water molecules go.  But, if we include the river bed and river banks into our fundamental system, then there is no emergent “top-down” influence.  I feel that claiming something has an emergent, top-down influence when the system is open is suspect.  It seems that those outside influences need to be brought within the explanation of the system in order to determine if there is strong emergence.  I’m sure there is plenty of debate on that particular point.

              In the last entry, I argued that the first aspect of strong emergence, the aspect of a disconnect between the “emergent” property and the underlying physics, was typically just another word for consciousness.  Or, I suggested the word “metaphysics” be used in this case.  So, what word should be used to describe this second aspect of strong emergence – the aspect of downward causation?  In my opinion, we already have a word for that:  “will”.  Maybe more commonly in philosophy, the term “agency” is used.  But, it seems to me that downward causation is just describing the higher-level system exerting its “will” on the lower-level system. 

              For the purposes of this discussion, I am not claiming any particular freedom in the term “will” in this case – i.e. I’m not claiming that this is necessarily “free will”.  If you are a determinist, then maybe you would call it “determined will”, I don’t know.  In fact, even though I am a strong proponent of free will itself, I don’t think that downward causation always fits under the category of “free” will.  Just “will” – or “agency” – or maybe even “purpose”.  I think that life is actually an example of this concept.  Living things exhibit a purpose.  Thus, I would consider life to be a strongly emergent property, except that I would never use the confusing term “strong emergence.”

              So, to summarize, I think that the terms “weak emergence” and “strong emergence” are very misleading.  I propose three terms to describe these ideas.  First, the term “emergence” would be retained to describe those things that would be typically categorized under “weak emergence.”  Then I would use the term “consciousness” for those things that have the first aspect of strong emergence – that they somehow depart from (or modify) the laws of physics.  And finally, I would use the term “will” or “agency” for those things that exert downward causation that is independent of the underlying physics.  I have previously introduced my thinking about how I see consciousness and agency as being connected in human behavior in my discussion on the soul <here>.  I think consciousness and will are related, but are not the same thing. 

              Now, given this background, we will go back to the discussion on water molecules and liquidity.  Next time.

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[1] Is there some bigotry on our part when we place particle physics always at the “bottom” and things like life and consciousness at the “top”?  Why should increasing complexity be seen as “higher than” or “above” things that are less complex?  And are quarks and gluons actually less complex than humans?  If so, then why is quantum mechanics so difficult for humans to understand?

Emergence 4 – Weak and Strong Emergence

               In previous entries I have been exploring the scientific and philosophical concept of “emergence” (starting <here>).  Emergence is the concept that something can have a property that isn’t apparent in its individual parts.  I’m interested in this concept because a common refrain from neuroscience is that consciousness arises as an emergent property of complex networks of neurons.  I won’t rehash the previous discussions – you can read them for reference – but my contention is that when you really analyze what emergence means when it is used to describe consciousness, it is actually just another word for consciousness.  

              Last time, we started considering the property of “wetness” that emerges when a bunch of water molecules get together at the right temperature and pressure.  The individual molecules themselves could not be described as being wet, yet the property of wetness emerges from the collection of them.  There are at least three aspects to consider regarding the wetness of water:  1) wetness can refer to the sensation that we feel when we touch something wet, 2) wetness (or liquidity) can refer to the fact that the water is in a state of being a liquid (with all of the properties that flow from being a liquid), and 3) “wetness” of water is a measurable property. 

              Previously we discussed the first aspect about the sensation of wetness <here>.  In this entry, I’m going to be addressing the second instance – the idea of liquidity as an emergent property.  However, before we dive into that, we’re going to have to make a detour and discuss the concepts of “weak emergence” and “strong emergence”.  I really didn’t want to have to talk about these concepts, because I think they are totally misleading, and they have been variously defined by different academicians, which adds to the confusion.  I will try to be brief and, if you are really interested in this topic, there are plenty of videos floating around the internet that discuss weak and strong emergence in various levels of depth. 

              “Weak emergence” refers to emergent properties that are, at least in principle, explainable by the underlying physical properties.  If you have a materialist or physicalist viewpoint, then you generally think that all emergent properties can be explained by the underlying physics, and thus weak emergence is all there is.  Weak emergence is extremely powerful in science, engineering, and mathematics, because it allows you to describe how things work in the universe without having to resort to incredibly complicated and highly impractical calculations based on fundamental particles and fundamental principles.  For example, you can describe the trajectory of a ball knowing the equations for position, velocity, and acceleration and the initial conditions of the throwing of the ball.  You don’t have to know how many atoms are in the ball or what kind of atoms the ball is composed of or anything like that.  The beauty of this approach is that, given just a few bits of information, you can figure out when and where the ball will hit the ground with a very high degree of accuracy.  It’s amazing that this kind of “simplification” works so well.  Somewhere, in your early physics classes, you started with these equations and built a lot more complicated equations after that to describe the activity of all sorts of things.  The point is that you could go through your entire Dynamics 101 and Dynamics 201 courses and never even have to know that objects are composed of atoms.  It never needs to come up.  However, everyone would agree (I’m pretty sure) that you could do these calculations at the atomic level if you had the time, computing power, and appropriate knowledge of the location and velocities of all of the particles involved.  Further, if you did those calculations, you’d come up with the same answer that you get with your Dynamics 101 equations.  Either approach is describing the same event, it’s just that using the description of the dynamics of physical objects is soooo much more practical.  In this case, weak emergence isn’t describing anything new – it’s just that weak emergence allows us to describe things in a much simpler way and only have to know about the particular scale of the system we are interested in.  It prevents us from having to work our way down to fundamental particles and fundamental physical laws to describe everything we encounter.  Weak emergence is incredibly powerful – it is not “weak” at all in that sense – and nearly all of science and engineering owes its existence to weakly emergent properties.  It allows us to observe properties and make predictions and perform repeatable experiments.  I don’t want to downplay it.  But, in my opinion, it has nothing to do with human consciousness and it really has no relation to strong emergence.

              In “strong emergence”, the connection between the higher-level events and the underlying physics becomes strained and broken in some manner.  This makes strong emergence fundamentally different than weak emergence.  But, to further complicate the whole issue, there are two features that tend to get combined under the heading of “strong emergence” that are also so different from one another that they should each be given a separate descriptive word – i.e. they shouldn’t be combined under a single word.  It’s a lot to unravel, so please bear with me for a bit as I describe these two features and then try to bring things back around to the topic at hand.

              First, strong emergence has the feature of describing some new emergent property that cannot, even in principle, be explained by the underlying physics.  If you are a physicalist, in particular a reductionist, then you would not accept that anything like strong emergence exists.  You would simply say that, sure, there may be some things that we can’t explain based on the underlying physics right now, but that is just a limitation on our practical ability to gain the necessary knowledge of the initial conditions and make the necessary calculations.  You would claim that everything would be, in principle, explained by the underlying physics.  Strong emergence, if it exists, implies that the underlying physics is not sufficient to explain the universe[1].  Many proponents of strong emergence gloss over this critical point.  With strong emergence, a property emerges from the underlying components that cannot ever be explained by any detailed description of the underlying components.  Sometimes, a scientist or philosopher will claim (or admit) that consciousness is, quite possibly, the only example of strong emergence that exists in the universe.  I find that kind of funny.  If you think that way, why call it “strong emergence” then?  Why not just call it consciousness?  If that is the case, then how does strong emergence explain anything new about consciousness anyway?

              OK, but before I get to the second major feature of strong emergence, I want to stop here and point out what I believe is a sleight-of-hand deception that is occurring here.  By using the word “emergence” and tacking on the “weak” or “strong” descriptor, it gives us the sense that the two terms are just describing degrees of the same thing.  It seems like strong emergence is just a bit “more” emergent than weak emergence.  They must be analogous to each other, right?  They’re just on some kind of continuum from weak to moderate to strong, right? 

              Wrong!  This is why I don’t like the two terms at all.  They are describing two fundamentally different concepts and they should not be given the same descriptors.  There is a world of difference between a way of describing a system that is simply a shorthand method allowing us to do physics, and the generation of some completely new feature that doesn’t follow the fundamental physical laws.  The fact that most physicalists (which probably describes most scientists) would readily accept that weak emergence exists everywhere and strong emergence does not exist anywhere, should give you a clue that we’re not describing minor differences in degree!

              If we were to create a Venn diagram of the universe of weak emergence and the universe of strong emergence, I submit that the only overlapping region of the entire diagram would be under the heading of “terms that contain the word ‘emergence’”.  It’s like if we renamed the direction “south” to be “weak north” and we renamed the direction “north” to be “strong north”.  That doesn’t make strong north and weak north related – they are polar opposites (literally)!  The terms strong emergence and weak emergence have a similar relationship. 

              I don’t really know how these two terms came to be connected with the same word “emergence.”  Personally, I would leave the term “emergence” to be used exclusively about everything that we put into the category of weak emergence.  I would then eliminate the term “strong emergence” from the language of science and philosophy.  As I have already claimed (<here>, <here>, and <here>), strong emergence is simply another word for consciousness, and only adds confusion and zero additional clarity to the whole discussion.  If there is resistance to use the term consciousness (because, let’s say, you think that quantum entanglement is also an example of strong emergence[2]), then what alternative term should be used?  Well, in strong emergence, we are describing a new property that is apart from, or in a systems sense, “above” or “beyond”, the fundamental laws of physics.  Don’t we already have a term for “beyond physics”?  Well…yes we do:  “metaphysics”!  It’s already a common English word, defined appropriately and ready to be used.

              Haha!  Most people who want to describe consciousness as “strong emergence” wouldn’t be caught dead using the term “metaphysics” in place of strong emergence.  Why?  I can tell you why[3].  It’s because weak emergence, and thus just simply “emergence”, is strongly tied to fundamental physics, physicalism and reductionism.  These are all well-respected in the STEM world.  So, the term “strong emergence” becomes a reasonably well-respected term because of its association with weak emergence.  But, my point is, they don’t associate with each other, they have never associated with each other, and they don’t even live in the same neighborhood.  Replace “strong emergence” with “metaphysical property” and all of a sudden the concept will be shunned by the STEM world. 

              Given all that, I know that no one is going to swap the term “strong emergence” with “metaphysical property”.  It just won’t happen.  But it should.  So, I’ll make a more practical suggestion:  replace the term “strong emergence” with the term “consciousness”.  That would solve the issue, in my opinion.

              I’m going to stop here in this entry, as I think I’ve sufficiently offended all lovers of “strong emergence”.  And I haven’t even addressed the second feature of strong emergence – a property that, not only should it not be lumped with “weak emergence”, it should not even be lumped with “strong emergence” or “metaphysical properties” or even “consciousness”!  But that will be for the next entry – here.

              And, of course, I am supposed to talk about the liquidity of water as an emergent property.  That’s going to have to wait until I finish this discussion of weak and strong emergence.  That is here.

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[1] I will just acknowledge here that there are some philosophers who claim to have identified a way to claim that strong emergence still acts within the laws of physics and, instead, just puts boundaries around what can happen (e.g. Nancey Murphy and others).  But I can’t address that issue right now and I’m not really sure well-accepted that approach is in the broader scientific and philosophical communities.

[2] Surely a topic for another time – not now!

[3] This is just my conjecture.  I’m not expecting any academician to admit to this!

Emergence 3 - Wetness of Water

               A while back, I started exploring the idea of “emergence” in a previous entry <here> and then again <here>.  Emergence is the idea that something can have a property that doesn’t exist in its individual parts and wouldn’t have been anticipated just by observing the parts themselves.  I’m interested in the idea of emergence because it is so commonly used as a possible explanation of how consciousness arises from a network of neurons in the brain.  “Consciousness as emergence” is the idea that when a complex network of neurons interact, consciousness emerges from that network even though it is not present in any one neuron.  My contention is that, when you really analyze what emergence is, it is actually just another word for consciousness.  If my contention is correct, then saying that consciousness is an emergent property of the brain is the same as saying “consciousness is consciousness”, which, of course, explains nothing.

              So far, I’ve talked about the meaning of words that emerge from various arrangements of letters, and the image of a picture that emerges from a painting (example:  Mona Lisa).  In both cases, the “emergent property” was shown to be equivalent to the conscious perception of that property.  However, it seems to me that there is a lot of disagreement about what constitutes an emergent property, so I’m not sure my first two examples are sufficient to establish my contention.

              Therefore, today I’m going to address the property of “wetness” that emerges when a bunch of water molecules get together at the right temperature and pressure.  The molecules themselves could not be described as being wet, yet the property of wetness emerges from the collection of them.  I think this is pretty much the quintessential example of an emergent property, which I expect is due to the use of this example by the late philosopher John Searle.  Searle is probably best known for his “Chinese Room” analogy of consciousness.  In my opinion, Searle is one of those people you enjoy listening to even when you don’t agree with them!  Here’s how he used the emergent property of the wetness of water in his arguments:

 “All of our conscious states, without exception, are caused by lower level neurobiological processes in the brain, and they are realized in the brain as higher level, or system features. It’s about as mysterious as the liquidity of water, right? The liquidity is not an extra juice squirted out by the H₂O molecules, it’s a condition that the system is in; and just as the jar full of water can go from a liquid to solid, depending on the behavior of the molecules, so your brain can go from a state of being conscious to a state of being unconscious, depending on the behavior of the molecules.” — John Searle

               I don’t think anyone would argue that the wetness or liquidity of water is not an example of an emergent property (except for those who don’t think there are any emergent properties at all).  Thus, if I could apply my previous reasoning regarding words and paintings and show that the emergence of wetness is just conscious perception, then I think I would have a strong argument to generalize to “all” emergent properties (until someone can show a property that breaks the rule).  However, it’s not that easy in this case, and that’s because the idea of “wetness” or “liquidity” has multiple aspects to it.

               There are at least three aspects to what we mean when we talk about the wetness of water that I will need to address.  I’m going to address the easy one in this entry, and address the other two in future entries because they have broader implications to this discussion.  But let me introduce the three aspects here so you can see where I’m going.  First, wetness can refer to the sensation that we feel when we touch something wet.  There is “something that it is like” to touch something wet.  Second – and here the term “liquidity” or “liquid” is generally used – wetness can refer to the fact that the water is in a state of being a liquid with all of the properties that flow (literally) from being a liquid.  The third aspect is that the “wetness” of water is a measurable property.  Soapy water, for example, is “wetter” than pure water and has properties that can be objectively measured to demonstrate the degree of wetness.  Thus, surely, if I can independently measure a property, I can’t claim that it is “all in our mind” can I?  That will be a discussion for the future.

               In this entry, I’m taking the first instance where wetness refers to the way wet things feel.  When we touch something wet, there is a way that feels to us that is instantly recognizable from touching something solid.  Often, we can “see” wetness as well because of the way light shines off of something that is wet, though we can also be fooled by, say, a very high gloss solid surface.  The point is that when we are talking about this instance of wetness, we are talking about a sensation that we feel through our hands or wherever it is that we are touching something wet.

               If you’ve read through my first two entries on this topic, then what I say here should be very familiar and not surprising.  In this case, feeling the wetness of water is directly analogous to seeing the Mona Lisa in a painting – it’s just a different sensory modality.  Given that, we can follow the same path and ask ourselves “where does the wetness exist?”

               In the case of wetness as I’ve defined it, we can easily see that wetness does not exist in the water itself.  That’s because I’m focusing on wetness as a sensation.  The water molecules themselves do not “feel” anything (though they do experience forces from other water molecules – something we’ll have to address in the next entry).  So, when we describe the sensation of wetness, we are clearly talking about something that happens to us when we feel something wet.  Where does that sensation of wetness “reside”?  When we touch a wet surface, the water molecules must interact without our touch sensing organs in our fingertips.  Maybe the Merkel cells or Meissner’s corpuscles are activated in a certain pattern.  I’m going to make a guess that a single water molecule is not enough to activate one of these sensory endings.  Wetness, it would seem, almost certainly requires the activation of multiple sensory endings in a certain pattern.  I’m not sure what that pattern is exactly, but it would surely be spread out among an area of skin, sending an array of action potentials back to the brain.  Although there would likely be some processing of these signals in the dorsal root ganglion and maybe spinal cord, nowhere in the transmission of these signals is there a single cell that lights up to indicate the sensation of wetness.  This is completely analogous to the discussion of seeing the Mona Lisa.  There is nothing in the transmission itself that indicates the perception of the emergent property we are discussing. 

               Ultimately, as before, the sensation of wetness never even coalesces in the neurons in our brain.  There is processing of the sensory signals for sure, but there is not a single “endpoint” neuron that lights up with a little display that flashes “wet, wet, wet” to indicate the sensation of wetness has been perceived.  Instead, it is our conscious perception of wetness that is the “endpoint” of this process.  Thus, as we have found with other emergent properties, the emergent property of wetness just is the conscious perception of wetness.  Emergence is consciousness.  Emergence, in this case, isn’t analogous to consciousness.  They are the same thing.

               I acknowledge that this entry is not a particularly deep argument.  By focusing on the sensation of wetness, I’ve basically asked “where is the conscious perception of wetness?” and then answered that it is in our consciousness.  It’s kind of obvious.  But I’ve come across some authors on the topic of consciousness who don’t seem to recognize this obvious link, and so I felt it was necessary to spend a bit of time on this.

              What is more interesting is the question of the second and third aspects of wetness.  Can these be considered emergent properties?  And, if so, surely they do not reside solely in our consciousness, do they?  We’ll address those issues next.

Emergence 2 – Mona Lisa

           I started exploring the idea of “emergence” in a previous entry <here>.  Emergence is the idea that something can have a property that doesn’t exist in its individual parts.  This could be the fluidity of water or the solidity of ice or even the color of ice.  But it could also be the properties of ant colonies that emerge when millions of ants work together and it could be the properties of societies when a large group of humans get together.  In fact, in some sense, anything that is not a fundamental principle could be considered an emergent property.  And, as I mentioned previously, probably the most interesting proposed example of an emergent property is consciousness.  “Consciousness as emergence” is the idea that when a complex network of neurons interact, consciousness emerges from that network even though it is not present in any one neuron. 

             In the first entry on this topic, I discussed the emergent property of meaning that arises from a collection of letters.  My contention was that the emergent property of meaning only exists in one place:  the conscious perception of an individual.  Thus, the “emergence” in this case can be boiled down to conscious perception and, in the end, the concept of emergence is exposed to be just another word for consciousness.  However, there is some disagreement about whether the meaning that emerges from letters is really the same as most commonly accepted examples of emergence, so it is necessary to dig deeper into this topic.

             Today I’d like to use what I think is a more commonly accepted example of emergence:  an image that emerges from a painting.  Let’s take the Mona Lisa painting by Leonardo da Vinci.  It is, at a molecular level, just a bunch of molecules spread over a canvas.  None of the molecules in the paint or even in the canvas have any resemblance to, or concept of, the image of Mona Lisa that we see when we look at the picture.  Thus, the image that we see can be said to be an emergent property of the painting or an emergent property of the molecules of paint that make up the image.  The sum of the paint molecules in the Mona Lisa is certainly greater than just the collection of paint molecules themselves.  There is something more there – something that emerges when the molecules are arranged carefully (by da Vinci) that could not have been predicted or expected by just examining the molecules of paint themselves.

             The question we want to consider is this:  where is the image of the Mona Lisa with respect to the painting?  Where does this emergent property exist?

             In order to explain the point I would like to make, I’m going to simplify the situation with some simplifying assumptions.  I don’t think any of these simplifications affect my conclusion, so please bear with the simplifications and then we can circle back and the end and consider whether the real complexity of the situation changes the conclusions I have drawn.

             First, I’m going to use a printed image of the Mona Lisa instead of the painting itself.  Specifically, a laser-printed image of the Mona Lisa.  Don’t worry – the image will be immediately recognizable when you look at the page.  But, if you were to greatly magnify the printed page, you would see that it is really just composed of a series of printed dots of different colors.  Each dot is a single color, based on the ink colors available in the printer.  We could go deeper in magnification and talk about the molecules that make up each dot, but that’s not necessary for the purposes of this thought experiment.  I think it will be obvious that the image of the Mona Lisa is not resident in the dots of different colored ink.  The dots themselves have no knowledge of what image they are a part of, obviously.  The printer itself was not given information about Mona Lisa – it was only given information about what color dots to print where.  But there is one thing for certain:  when we look at the page, we see Mona Lisa.

             Now I’m going to make a couple of major simplifying assumptions.  Let us imagine that there is a one-to-one match between the dots of colored ink on the paper and the photons of different color being reflected off of the page.  In this case, a single blue photon is reflected off of a single blue dot on the page and heads to your eye.  A single red photon is reflected off of a single red dot and heads to your eye.  At some given instant in time, all of the differently colored photons are reflected off of their respective dots and head to your eye.  If all of the photons were in sync with one another and timed just right, there would be a mass of colored photons heading toward your eye.  Each color and the location of each dot is preserved in that mass, or column, of photons.  Thus, in some way, you could slice that column of photons and get an image of the Mona Lisa.  But, of course, the photons, like the dots on the page, have no knowledge of the Mona Lisa.  They are just photons taking a specific color and existing in a specific point in space.  The emergent property of the image of the Mona Lisa is nowhere to be found in this collection of photons.

             This group of photons now enters your eye where they activate the rod and cone receptors in your retina.  My second simplifying assumption is that each photon actives a single cone cell, which then generates an action potential that travels along a single nerve fiber in the optic nerve.  Thus, there is a one-to-one correlation between the whole set of photons and the action potentials on multiple fibers in the optic nerve.  If the nerve fibers in the optic nerve preserved the geometric relationship of the cones in the retina, you could slice the nerve at some point and recreate the “digital image” of the Mona Lisa (after converting the action potentials to their indicated colors).  Again, that is an oversimplification for the purpose of this analogy.  The point is that the light image of the Mona Lisa lands on the retina and activates the appropriate cones, which send their signals along the optic nerve to the occipital cortex of the brain.  The parallel arrangement of the signals in the optic nerve are preserved, since each cone cell has a direct “single line” connection to the brain (due to my simplifications).

             The parallel signals along the optic nerve now enter the occipital cortex, where they kick off a complex neural network that extends around the visual cortex.  Some of one side of the image is split off and mixes with the other side.  Edges are identified.  Colors are identified.  The network of neural signals keeps expanding to different areas of the brain.  Memory is activated and the image is compared to past knowledge and things we recognize from our past.  All of this happens pretty quickly because it doesn’t take us long to glance at the picture of Mona Lisa before we recognize it as being Mona Lisa.

             Some might think that eventually these neural signals end up activating some single neuron in the brain that only lights up when you look at a picture of Mona Lisa.  That is sometimes referred to as the “grandmother cell hypothesis” though I’m not sure that was ever a serious scientific idea.  But there is no such single neuron.  Instead, the collective activity of the neural networks across the brain give rise to the general awareness, and thus conscious perception, of Mona Lisa.

             My contention is that, until this final step of consciousness, there is no place for any emergence of the image of Mona Lisa.  In this whole process, from the dots on the page, through the light transmission, to the neural activity - all the way to the brain – there is no place where the information is brought together into a cohesive “image of Mona Lisa”.  It doesn’t happen until it happens in our brain and we have the conscious recognition of “oh – that’s the Mona Lisa.” 

             It is reasonable to wonder whether my simplifications resulted in my “factoring out” emergence from what really happens.  Of course the whole process is much more complex.  Lots of photons are bouncing off of each dot on the page and heading to the eye, not a single photon.  They are coming at different angles, different colors, etc.  But photons stay as photons – they don’t mix together to create a cohesive image – so I don’t think anyone would claim that the emergence of the image of Mona Lisa arises from the reflection or travelling of photons from the dots on the page.  However, once the photons get to the rods and cones in the retina, the processing is certainly a lot more complex than my simplification.  There are ganglion cells in the retina and some pretty complex processing happens even just between the cones/rods and the ganglion cells.  My argument here is that the processing in the eye is just an extension of the processing that is carried on in the visual cortex.  It can all be lumped under the category of neural processing in the “brain” and, in fact, the retina is considered part of the central nervous system.  Thus somewhere, somehow, the image of Mona Lisa arises from the neural processing in our brain (or central nervous system, if you prefer).  The emergent property of the image – the Mona Lisa - does not exist until we consciously perceive it.  My contention is that every example of emergence (at least every example of “weak emergence”) boils down to this same conclusion:  the “emergent property” only emerges in our conscious perception of it, and nowhere else.

 ~~

             I imagine a discussion with someone about how it is that consciousness just arises from the neural activity from the brain.  I would maintain that consciousness is non-material [see here], whereas they would maintain that consciousness is purely a physical thing that naturally arises from the action of neurons.

             “If consciousness is purely a physical process, what is the means by which it just arises from neural activity?” I would ask.

             “Consciousness is just an emergent property that naturally arises from the activity of neurons, just like many other emergent properties of material objects.”

             “An emergent property?  What does that mean???  Could you give me an example of an emergent property outside of consciousness itself?”

             “Well, for example, imagine you’re looking at the painting of the Mona Lisa…”

Emergence 3 - Wetness of Water

Emergence 1 – My Contention

             I want to explore the idea of “emergence” or “emergent properties”, as I understand the philosophical concept.  Emergence is probably more popularly summed up in the common phrase “The whole is greater than the sum of its parts.”  Emergence is the idea that something can have a property that doesn’t exist in its individual parts.  I think the most common example typically put forth as an emergent property is the “wetness” or “fluidity” of water.  Water is just a collection of H2O molecules.  An H2O molecule has no property, by itself, that could be called wetness.  But when you put a bunch of them together (and the temperature and pressure are right), the property of wetness “emerges” out of the collection of molecules, and thus it is considered an emergent property.  An emergent property is also frequently defined as a property that you would not (or could not?) have predicted by just looking at the individual parts.  The idea of emergent properties is apparent in everything from molecules to societies.

             There are lots of examples of emergent properties, and I will explore some in future entries.  However, there is really only one so-called emergent property that I care about:  consciousness.  How consciousness is related to the actions of a bunch of neurons communicating with one another is of great interest to me.  There are many people who consider consciousness to be the quintessential example of an emergent property.  They say that consciousness is a property that naturally arises from the complex interaction of neural networks.  This allows them to consider consciousness to be a natural part of the material world – as natural as the wetness of water - and nothing more.  Importantly, this allows them to reject any idea that consciousness is non-material or immaterial.  I think that is a mistake (see here and here), and I hope to show why I say that over the course of a few thought experiments that I will initiate with this blog entry.  My contention is this:  calling consciousness an emergent property of the brain is tantamount to saying that “consciousness is the property of exhibiting consciousness” …which is no explanation at all.  Further, I want to make the contention that all “emergent properties” are conscious perceptions.  I contend that “emergence” and “consciousness” are the same things, and so you can’t use one to explain the other, because all you are saying is “consciousness is consciousness.” 

             This is a tricky argument for me to explain, so I’m going to unravel it slowly, hoping that what I say makes sense.  This is my first time trying to explain this concept, so it may be a bit rocky.  I would certainly be interested in people’s comments on the matter.

             I’m going to start my series of thought experiments about emergent properties by using an example that I have to admit is marginally “emergent”:  specifically, the meaning of words.  If we string together a couple of “A”s, a couple of “I”s and an “L”, “M” and “V” in the right order, we can create a meaning that emerges from those letters that is certainly not contained in any single letter and could not be predicted by examining the letters alone.  We could string those letters together to create the phrase “I AM ALIVE”, which has a very significant meaning that has nothing to do with the letters themselves.  The meaning of the phrase could be considered an emergent property of those letters.

             My question now is this:  where does the emergent property of those letters exist?  Does it exist on the page (or screen) where those letters appear?  Does the emergent property somehow float above the letters in some way?  This is obviously not the case.  If an ant crawls across the page, it doesn’t encounter the meaning of the phrase encompassed by the letters.  If a bird flies overhead and sees the entire phrase, it doesn’t encounter the emergent property of the meaning of the phrase.  In fact, if a non-English speaking person, or an illiterate person, looks at the entire phrase, they also will not experience the emergent property of these letters.  The only one who experiences it is an individual who knows the meaning of the phrase as it is written.  Thus, the emergent property exists only in the minds of human beings.  Further, it exists only in the minds of some human beings.  Thus, since not all seeing humans experience the meaning of the phrase, I think it should be clear that the emergent property does not exist in the visual perception of the words or even in the visual cortex.  Two different people can look at the phrase and see exactly the same image in their brains, but one experiences the meaning and the other, who doesn’t know English, experiences nothing.  In fact, it is not until the firing of various neurons in our brain are brought together into our conscious perception of the fact that the image we see on the page is actually a phrase, and the phrase means something, that we experience the emergent property of meaning.  Thus, in this example, the emergent property of the meaning of the phrase is our conscious perception of it.  The emergent property just is conscious perception, in this case.  If we then say that the meaning of letters is an emergent property, we have not found a new property at all.  All we are describing is our conscious perception of the meaning.  We initially ascribed the emergent property to the letters themselves, but that’s not where the emergent property exists.  It exists nowhere but in our consciousness.  It just is our consciousness.  There is no difference between the emergent property of “meaning” and the conscious perception of meaning.  I hope that makes sense.

             If the meaning of words were a clear example of what people call an emergent property, then I might be able to rest my case with this one example.  But calling the meaning of words an emergent property is not particularly clear.  Most “true” emergent properties spontaneously arise from the collection of their parts.  The meaning of words does not naturally arise from their existence.  Meaning also requires a set of rules of language, rules that have to also be understood and agreed on by others who use the same language.  For the words to have the meaning they have, there are a lot of outside things that have to be brought to bear upon the series of vertical, horizontal, and slanted lines that make up the phrase “I AM ALIVE”.  Given that, I don’t think most people would consider “meaning” to be an emergent property in the same way that “wetness” is an emergent property.  I’m not sure I totally agree with that, since it seems to me that if you consider the parts of your system to be the letters plus the linguistic rules of English, then you can still say that meaning emerges from the sum of the parts, it’s just that the parts are a lot more complex.  But I’m not going to argue that here.

             In summary, to the extent that the property of “meaning” is an emergent property of letters, the concept of emergence is shown to simply be a restatement of the property of consciousness.  They are one and the same.  The idea of meaning itself cannot exist without consciousness.  My goal is to show that the same thought process can be applied to more standard examples of emergence and that the same conclusions can be drawn.