When you reach out to grab your cup of coffee, what is causing this action? Is there a special internal ‘you’ somewhere in there pulling the levers? If so, what is this ‘you’ made of and how does it cause these limbs of meat and bone to move? Or do you believe that you are merely a big heap of atoms, nothing more? How then do mere atoms ‘want’ to grab a cup of coffee?
These are some of the kinds of questions that rear their heads when we start to think about our ‘minds’; who ‘you’ are, what ‘you’ are made of and what our relationship is with the world around us. How is the mind different from the brain?
For a very long time a common view was held (and is still held by some people today) that ‘we’ are a non-physical essence or soul linked in some way to our physical brains — this is called ‘dualism’ because you believe in two types of ‘stuff’ — and this essence is able somehow to cause our brains and therefore our bodies to do things. But this concept is riddled with problems and I’m not going to go into them here suffice to say that very few people who’ve taken an interest in any kind of science of the mind would hold to it.
But in the absence of this non-physical explanation and in the light of the mounting evidence for the brain merely being ‘what the brain does’ we’re left in a bit of an awkward situation. How can mere atoms be emotionally moved by a song? How can bags of chemicals build a car? These kinds of questions become especially difficult when you happen to believe that the universe is such that there is a supreme being out there who has a purpose for you and yet you find dualism decidedly uncompelling. Reductive physicalism (i.e. a world which is only made of physical things that can be explained by describing the smallest parts) doesn’t really seem to have a place for a supreme, purposeful being.
A solution may be at hand however. What if we accept that, yes, atoms do clump together to form molecules and molecules clump together to form organisms that can act in their environment all in a kind of a ‘bottom-up’ path of causation. But then we will notice that things such as natural selection can themselves emerge and have a kind of a ‘top-down’ causation that, in turn, affects and improves these critters that have been produced purely by the actions of atoms. This gives us a way to view the world in the light of the best available evidence (i.e. we can have just atoms and we can include the power of natural selection and so on) at the same time as breaking away from the disconcerting concept of a world in which everything is driven by the mere mindless jiggling of atoms. This is called ‘non-reductive physicalism’ because we admit that we’re made of ordinary matter but the rules that guide atoms are not enough on their own to get us to where we currently are.
I think I spotted a flaw in this logic but in order to effectively illustrate what the error is I’m going to have to go off on a tangent and discuss a geeky bit of software called Conway’s Game of Life.
Conway’s Game of Life was created back in 1970 by mathematician John Horton Conway. In essence it’s a grid of blocks that can be either alive (black) or dead (white) in which each block conforms to four simple rules:
- If you’re alive and have one or less alive neighbours, you’ll die
- If you’re alive and have two or three alive neighbours, you’ll survive
- If you’re alive and have more than three alive neighbours, you’ll die
- If you’re dead and have three alive neighbours you’ll become alive
Using these four simple rules if you start off with a pattern of three dots selected one above the other like an ‘l’ you will find that the top and bottom dots will die (become white) because they each only have one neighbour. The middle dot will remain because it has two neighbours. The empty dots to the left and right of the middle dot will come alive because they both have exactly three alive neighbours. Once this has been calculated the grid is redrawn and you’ll notice that we now have three dots again but this time they’re side-by-side like a dash. If we apply these same rules again we’ll end up with the same configuration that we started with and so on and so on. Not really all that interesting but it’s a start.
There are many different configurations possible. Some of them remain static, some blink like the example above, some bloom out into endless randomness or collapse into a detritus of blinking and static objects. Some that have captured the imagination of many can even ‘travel’ across the screen endlessly or even generate repetitive patterns. See the image on the right for an example of one of the most common travelling objects called a ‘Glider’. See how it obeys the four rules and yet seems to have transcended them in some way. It now seems to have some additional rules like “move on a diagonal down the page and to the right”.
Here, have a play with this one online but please come back to see how this all relates to the seeming conundrum of minds, bodies and non-reductive physicalism.
Even more complex, see the example on the right of a ‘Gun’ which produces an endless stream of gliders. Now we can’t help but lose track of our four simple rules and we’re now seeing actual entities interacting with each other in a seeming causal manner. The gun has got two stopping/absorbing blocks with a couple of arrow-things that fly back and forward between them producing a stream of gliders which move diagonally away from the gun.
Can you see where this is going yet?
What we’re doing — albeit at a simplified level — is we’ve acknowledged that four simple rules can create some interesting patterns and then we’ve started thinking about the movements of the patterns themselves in a way that doesn’t seem to need to account for the four rules any more and, if we aren’t too careful, we might be tempted to think that the four rules weren’t sufficient to describe a ‘Gun’ that ‘produces’ ‘Gliders’.
This is exactly what I see happening when people posit non-reductive physicalism. As with Conway’s Game of Life where I can show you just enough yet be able to drag you back to admitting that, yes, these four simple rules are up to the task of producing what we perceive as guns and gliders so it is with the power of atoms to use a very simple set of rules (i.e. varying degrees of attraction/repulsion/jiggliness and so on) to produce molecules, chemicals and organisms which interact with each other. And to even provide us with brains in which to build mental constructs — which are themselves purely physical — of things such as glider factories and natural selection).
Non-reductive physicalism can be fairly described as “the idea that while mental states are caused by physical states they are not reducible to physical properties”. But what I think they are really saying is “In order for us to understand mental states, we can’t do it just by looking at the atoms that make them up”. Which, to me is exactly the same as saying “while glider guns are caused by the four rules they are not reducible to those rules” or, “In order for us to understand the behaviour of glider guns, we can’t do it just by looking at the the four rules”. But this speaks more to how our limited physical minds operate and how we require the use of analogies within analogies in order to form predictions and descriptions about the world. Not to how the world really is.
[The three images above are all sourced from the Wikipedia page on Conway's Game of Life. The Glider Gun image was created by Kieff.]