Simple diagram of The Application of Object-Oriented Design Techniques to the Evolution of the Architecture of a Large Legacy Software SystemIn a later post I'll tell you about the subsystems in the game Puzzle Strike, but first I thought we could discuss subsystems in general. Disclaimer: this post is intentionally labyrinthine because that's how thinking about things works.
Christopher Alexander
Christopher Alexander wrote the book on subsystems back in 1964 and it's still very much worth reading. He explained that sometimes a system is made up of a web of deeply interconnected relationships, or in other words: a mess. If changing any part of a system means you disrupt everything else, it's very hard to tinker with and improve without ruining something. On the other hand, it's easier to deal with a system when its made up of subsystems that (though they might themselves have interwoven webs of connections) do not have many connections among each other. This way, if you tinker with subsystem A, you probably won't ruin subsystem B by doing so.
Computer programmers are well aware of this concept. The Model-View-Controller architecture is one example in that it separates 1) the stuff the user interacts with, 2) the stuff the going on behind the scenes, and 3) the stuff the user sees. If you need to rewrite the stuff the user sees, this hopefully has little effect on the other two subsystems.
Another point Alexander brings up is that when we encounter some system, we naturally try to view it as a collection of subsytems, but the way we choose to carve things up can be based on our personal biases. In fact, it can even be determined by the language we speak. The set of all possible subsets of a system is usually so large that it far exceeds the number of words in our language. If our language happens to have a word that describes something, we're more likely to carve things up THAT way, just because we have a way of talking about it. Some languages have more words than ours does for snow, or more words for happiness, or more words for types of small rivers, etc.
As an example, imagine we were going to build a building. That's a very complicated system. What are the subsystems? Maybe plumbing, electrical, and load-bearing materials are three of the subsystems. After all, each of those things has a lot going on within the subsystem but relatively few connections between subsystems. But we could slice things up differently. Maybe some of the plumbing is made of copper pipes. Maybe some of the electrical has copper, and perhaps some other part of the building uses copper, too. Maybe copper parts are subsystem, all related in that they are susceptible to rust and water damage over time. Or what about simply "the bathroom" as a subsystem? Everything in a bathroom must work together, fit, be functional, not cost too much, be aesthetically pleasing, etc, even though it contains plumbing, electrical, and load-bearing materials.
Alexander's point with all that is actually that the best way to carve up a system tends to be the way that gives you the most disparate (as in not tightly woven) subsystems.
Many years ago, I was lucky enough to talk with Will Wright, and I read Notes on the Synthesis of Form on his recommendation. I saw on his whiteboard a diagram of the subsystems of The Sims Online. I couldn't help mentioning the idea that perhaps there was some other set of subsystems, and perhaps the ones written there were simply easier to SAY, as opposed to being the best ones. He said yes, good point, and looked at the diagram. Then he said, "actually, the instant messenger isn't really listed here, it's part of several of these subsystems but maybe it would be better to think of that as its own node."
Susan Blackmore
The ultimate in systems is the human brain (apologies to aliens out there with more advanced brains; we have not discovered you yet). Blackmore's 400 page textbook on consciousness is a baffling exploration of how the subsystems of our brain come together to create consciousness. Not baffling because it's poorly written (it's well-written, in fact) but baffling because the topic itself is so complex and hotly debated by experts.
Let's take a simple example like watching a frisbee fly through the air. How long does it take to recognize that what you're seeing is, in fact, a frisbee flying through the air? This is a much more complex question than it first appears. We expect there is some answer, such as 0.8 seconds or something, where we cross a threshold of knowing what we're looking at. In fact, many different subsystems of the brain are working independently here. The visual system tracks the movement of the object with jerky eye movements called saccades that you don't even know you're doing. Another system processes the color of the object, another the shape, and another the contrast. Another figures out how far away it probably is, which then gives you an idea how fast it is traveling. These systems work together to produce an answer "that is a frisbee."
But there are brief moments when some of these subsystems have figured out their parts, but the subsystems haven't yet formed a coherent whole of an answer. Can we say that you know it's a frisbee at this point? Not consciously, not yet. Your interpretation of what you're looking at slowly forms as brain subsystems form a better and better overal picture, but it's hard or impossible to say you go from not knowing to knowing it's a frisbee at any particular moment.
The Self
There's a concept all our brains have latched onto that some think is purely an illusion: the concept of self. In The Meme Machine, Blackmore explores the concept of a meme: an idea transmitted and copied from mind to mind analogous to how genes use organisms to reproduce themselves. The "O rly? owl" is an example meme. A certain picture with words that has been copied many times and lives in many of our minds.
Sometimes a collection of lots of memes can glom together into a huge thing that gets copied over and over. Together, this bundle is more successful at being copied than the separate pieces would have been. Blackmore calls this a memeplex. Any religion is a great example, but I won't dwell on that. "The self" is another example.
She calls the concept of self--the selfplex--the ultimate memeplex. She asserts that consciousness is definitely a feeling--there is such a thing as "what it feels like to be me, what it feels like to drive a car, etc," but that it does not actually do anything. The powerful illusion of self is a story we make up to explain what has happened. The story we make up that defines us is not even necessarily very accurate. We come up with wrong reasons for why we did things, we see ourselves differently than we really are. The whole business of "self" (the human kind of consciousness) is a merely a construct that memes have created in us so that we transmit them, she says. Here's a quote from The Meme Machine:
Second, I emphasize that consciousness cannot do anything. The subjectivity, the 'what it's like to be me now' is not a force, or a causal agent that can make things happen. When Benjamin poured out his cornflakes he may have been conscious, but the consciousness played no role in making him do it. The consciousness simply arose as what it was like to be that human being, taking those decisions, and doing those actions, and with a memeplex inside saying 'I am doing this'. Benjamin may think that if 'he' did not consciously make the decision then it would not happen. I say he would be wrong.
Surely you feel it's your turn to argue (there is no 'you' by the way), but really, that's not the point of all this. I have not even remotely presented a well enough picture of that theory for there to be anything to argue against. And it's the kind of thing we hope is wrong even if it's right, because we cling so dearly to the concept of self that any threat to it is terrifying.
Another problem with concept of self has to do with subsystems. There is part of our brain that compels us to find food, and a different part that compels sex. We like to achieve things. We like to be lazy and do nothing. We are a bundle of conflicting desires and wants. Think back to the frisbee example where all those subsystems work together to create a coherent picture ("frisbee flying through the air"), but that is not what it's like to be a "self." A self is an ever-conflicted set of subsystems, debating over which food, which sex, which achievements, which socializing, and which type of laziness we should pursue. Are "you" the lazy person who watches tv on your couch? Are "you" the student who seeks knowledge? What if you enjoy the adrenaline rush of sky diving, or riding a motorcycle, is that "the real you" who experiences those, and the rest of the time it's not "the real you"?
These are troubling questions, and I think we all experience the internal struggle of conflicting brain subsystems fighting over what your "self" really is. Sometimes we want food (that we know is bad for us). Sometimes we want fun experiences (that we know are dangerous, stupid, too expensive, etc, etc). Sometimes we want sex that "the real you" wouldn't want (there is no "real you"). Some enjoy alcohol or gambling too much, is the gambler or drinker the real you, or is the other you that doesn't think about those things the real one? The Buddhist answer is the same as Blackmore's: there is no self, that self is a box we put "ourselves" into to explain the experiences we have. We ebb and flow between states and that is all we are, no more or less.
You're confused now, but that's the point. It's the proper state of mind to be in when thinking about such a deeply interwoven set of subsystems as those that compose our selves, whatever those are. Next time, we'll look at the slightly simpler interwoven subsystems of a game: Puzzle Strike.