Wednesday, August 13, 2014

Contra Feyerabend

P Feyerabend

I've mentioned before that I don't like the work of Paul Feyerabend. Some groundwork for what is going to be done here. First of all, there is no complete Feyreabend philosophy. He didn't want a system, and didn't build one. This is not a criticism. If you want to critique him you have to critique individual papers and critiques. I doubt that Feyerabend could be so dense that everything they wrote was completely wrong, so I'm just going to stick to a few broad notions that he is famous for. I'm not going to, for instance, attack his historical work or explore his opinions on philosophy of mind. Instead, I'm going to go after the notion of epistemological anarchism and some of the arguments for it.

First of all, there is the notion that every observation is theory laden. This is either false or trivial, depending on how widely you let the notion of theory stretch. If you let the light tickling your retina be a theory, go ahead. But there is nothing special then about being "theory laden". No reason to suspect there is anything even subjective about them. Modern data-driven, nonparametric learning theory allows one to do explicit, quantitative mathematics without being "theory laden" in the way important to philosophers. I recently wrote a classifier to try to count the number of little buggers on some seagrass leaves. The data was collected totally independent of any input from me, it was already here by the time I joined the project. I don't even know what the schmutz is, biologically speaking. But despite having no theory of what they should look like, I managed to successfully classify them and other kinds of objects on the leaves using tools that didn't require me to have that knowledge. Theory-ladenness can matter, but it it isn't a necessary truth or even central to science.

L Valiant (nothing but pictures of black and white men in this post)

A simpler criticism can be made. Theory-ladenness is based on a false, "Good Old Fashioned AI" view of knowledge. When I walk through a room with a table, I don't and don't have to represent the room in my mind and trace my whole path through it before I walk. What I really do is much simpler to process and more fallible. You can see Leslie Valiant's excellent book Probably Approximately Correct for more on this subject.

S Wright

There is a deeper critique of epistemological anarchism, that it is doesn't give you what you say you want. There is nothing wrong with taking the 'let ten thousand flowers bloom' approach. But Darwin informed us that not all flowers are created equal. Seawall Wright introduced the very useful idea of a fitness landscape, evolution is an optimizing procedure on this landscape. Having many peaks and noise is not a flaw of this theory, just parts of it. The mass of beasts and scientists wander around this landscape, compelled to optimize. The difficulty with epistemological anarchism is that it uses the vague, equivocal notion of "incommensurability" as a hammer to flatten out the landscape. A totally flat landscape is what Feyerabend needs, a highly peaked landscape has far different properties (Stuart Kauffmann has done fascinating work in this area).

What we actually deal with is much harder work, people doing a lot of work actively trying to make better epistemologies. Science is a dirty, complicated, thing with complex dependencies, not a flat "everything is as good as everything else" field. One could say that the different notions of better ("unbiased" vs "efficient", for instance) make the choice of what one wants a bit subjective. But this is not anarchism, not a simple democracy. It's a hierarchical bureaucracy with republican elements at best. It is even possible that the dynamics is objective, as seen in statistical mechanics, but I won't defend that notion since.

A real example will hopefully help clarify. I was talking recently with a friend who is a bit of a biblical scholar. He mentioned that the discovery of some old papyrus falsified the work of many old time German historical critics that claimed it wasn't written for centuries after we now have documented evidence of their existence. According to Feyerabend, the historical critics should have said "We aren't interested in carbon dating. In this department, we use philology.". This isn't what they do. It's the epistemological anarchist thing to do, declare freedom from physics. It isn't what people do, not in the real world. So epistemological anarchism goes.

I've already mentioned the severe criticisms of the notions of democracy that were supposed to be what epistemological anarchism were defending. The problem is that real democracy, like real science, is much more complex, more peaked, more dynamic than the flat philosophical politics that Feyerabend defended.

So, what is left? Feyerabend left us a lot of criticism of over ambitious philosophy of science arguments. I've read philosophers call the discovery of the Higgs Boson in high energy physics "bad science" because it didn't exactly match their pre-conceived notions of what a good scientist should do (they used p-values at some point). Perhaps Feyerabend will help philosophers avoid hubris. This modest achievement doesn't leave the working scientist with much. That's only because there isn't much to it.

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