On Philosophy

December 2, 2007

When Models Collide

Filed under: Epistemology — Peter @ 12:00 am

Recently I have been thinking about knowledge in general with a focus on the models that are a key part of the way we understand the world. A model can be thought of as a logical construct, containing objects and properties structured by certain laws, which we put in a correspondence with the world in an attempt to explain it. I won’t go as far as to say that every theory is just some model or other. However, I will assert every theory contains some model, because it is only through a model of some kind that we can conceptualize the world and see patterns in it. But these models are not equally important in every theory. Some theories, such as many scientific ones, aim primarily to understand the structure of the world, and obviously for them the model is the primary focus, because all that matters for that purpose is make the model as perfect as possible. But other theories aim more to offer practical advice, and although some model is required to do so it’s correctness is somewhat tangential to the central issues. As long as the model is roughly correct that is sufficient, because perfect precision simply isn’t needed in these cases. I wouldn’t venture to guess which of these two kinds of theories is more important, however people usually place more emphasis on the first, probably because understanding the structure of reality seems like a more noble goal.

And when it comes to the first kind of theories there is a sharp divide between two general ways of constructing those models. On one hand we have the mechanical models. Mechanical models attempt to model the world using only a few simple kinds of objects and laws. So described it seems like an impossible task, given the amount of complexity we encounter it is hard to imagine that such a simple model could explain it all. And yet mechanical models have done surprisingly well at doing just that. On the other hand we have intuitive models. Instead of trying to model the world using an essentially arbitrary set of simple objects intuitive models attempt to divide up the world along the lines we are naturally inclined to do so, and to explain it with that set of objects and properties. This might seem like a better approach at first glance, because it is natural to suppose that the way we conceptualize the world is generally well-suited to describing it. And yet intuitive models have never met with much success when it comes to actually making predictions beyond the limited domains they were developed from. An example of such an intuitive model would be one that attempted to capture language by supposing that there exist objects corresponding to different meaning, and that we somehow connect to these objects when using language, thus explaining how we can communicate in a relatively unambiguous way. Obviously this model runs into problems when it comes to making specific claims; while we could interpret many cases of language use in terms of this model it is hard to make the model say anything on its own.

If we propose two radically different ways of modeling the world it seems unavoidable, to me, that they will come into conflict with each other; they both aim to explain the entire world, and will thus end up both voicing different views on the same phenomena. Of course if we had the right frame of mind there is nothing that stops us from accepting both models; nothing in either model will explicitly reject the other, and I guess it isn’t impossible for someone to believe in two different explanations for the same thing. But we aren’t devising these models simply because of curiosity, we want to know how the world works. And thus we want to know which model is best, which means we want to know which one lines up best with reality. Of course it is still possible that there two kinds of models could manage to tie, they could make the same predictions, or they might both run into irresolvable problems that only the other can solve. But that’s probably not the situation we will find ourselves in, it is much more likely that one of these ways of modeling the world will turn out to be better than the other. And we will also find ourselves in the position of having to pick one or the other when it comes to making bold claims, claims about what something really is. Recently this kind of situation has arisen with respect to the nature of the mind, with the mechanical and intuitive models both making claims about what the mind really is. Clearly the mind can’t be two different things, and so we must pick one model as superior to the other.

Obviously when we are faced with two different models we should always pick the stronger model, which makes more precise predictions, and the more accurate one, which turns out to be correct more often in its predictions. At first glance it seems that the mechanical models obviously have the upper hand on intuitive models when it comes to both these criteria. Modern mechanical models claim to capture literally everything, and they make very precise numerical predictions about those things that usually turn out to be correct. But, it may be objected, when it comes to even moderately complex phenomena it stops being practically possible to carry out the calculations the mechanical model would require of us. Thus intuitive models may actually be superior when it comes to large-scale phenomena because they actually make claims. However, we have strong theoreticals reasons to believe that we could, in principle, carry out the calculations required of us for large scale phenomena, it’s just that we lack the practical resources to do so. On the other hand it isn’t practical reasons that keep the intuitive models from making stronger or more accurate predictions, but rather their inherent limitations. Thus we have reason to believe that the mechanical models are superior to the intuitive models, in principle, even if, on practical terms, it may be wise to stick to the intuitive models in many situations.

Is it possible to save our intuitive models? In theory it might be possible to tighten them up, both making them stronger and more accurate while still retaining their intuitive character. Admittedly I don’t see how this can be done, but my lack of imagination doesn’t make it impossible. If it could be done it would be essentially a reverse of what happened when mechanical models were first invented, which were initially the ones that were weaker and less precise, but which were eventually improved to be superior. Another way to save our intuitive models would be to give up on the idea that ultimately they reflect the world. Instead we can understand them as rough approximations of it, with the objects and properties in our intuitive models standing for something in the mechanical model that really captures the world. To save our intuitive models in this way means that they cease to be able to answer our questions about the structure of the world. But, on the up side, by making these adjustments we can continue to use them without foolishly acting as if they were the superior models. And thus it is the alternative I prefer, because failing to embrace one of these options makes any use of the intuitive models simply absurd, either because it would essentially express a contradiction within what we believe or would represent an intentional blindness to the facts.

Naturally such a discussion raises some questions about philosophy. Does philosophy make mistakes by sticking to intuitive models when the mechanical models are obviously superior? The answer depends on what philosophy we are considering. Certainly some philosophy makes this mistake, including a lot of metaphysics. But, with the right intent even metaphysics can be done without running into these problems. As mentioned above all we have to do is accept that in some way our model must really be an oblique way of talking about some mechanical model. Obviously this frustrates projects that set our explicitly to say what the nature of the world really is. But a great deal of metaphysics can be interpreted productively as a search for finding practical and mostly accurate ways of conceptualizing phenomena so as to avoid certain errors we tend to make while thinking about them. And outside of this most philosophy can be seen as focused more on giving advice than on the model itself, making them the second kind of theories mentioned in the beginning, which are relatively independent of models. Thus philosophy is, for the most part, safe from the problem of illegitimately embracing intuitive models in any meaningful way, whatever other problems it may actually suffer from.

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