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.
[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!
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