Tuesday, 21 September 2010
::: Doing Without Theory
Peter Vickers

We are used to the idea that philosophy of science is populated by intractable debates. Opponents with different views are joined in battle, rather like knights at a medieval joust. They both go through their repertoire of rehearsed assaults; and these are deflected by their opponent's heavy armor. There is much noise and fury, but nothing changes. Come back next year and it will all be the same.

This expectation is so familiar that it has found a place in the literature. Blackwell's has a lovely little volume, Contemporary Debates in Philosophy of Science, that puts twelve pairs of modern knights through their paces. It is as timely a source today as it was over six years ago when it was published.

Sometimes, however, we find a way to change things so much that the old battles are dissolved. That discovery is what today's speaker is bringing us. He is Peter Vickers, who is one of the Postdoctoral Fellows in the Center this year. He is speaking early in the year in order to foreshadow the sort of work he will be doing during his visit. He prudently offers a rather strong disclaimer. He will be describing a project, not a completed set of claims. But if the project succeeds, he will do to many debates in philosophy of science what gunpowder did to the ways of the heavily armored medieval knights.

The idea originated in his dissertation project at the University of Leeds. He had been looking at the fierce debates over whether certain theories in physics are logically inconsistent. One in particular caught his attention. It was the claim by Mathias Frisch to have shown an inconsistency in classical electrodynamics; and the counterclaim by Gordon Belot and Fred Muller that Frisch had failed.

What Pete (as he calls himself) noticed was that both agreed on the details of almost everything claimed by the other side. The only real disagreement was over just what counts as classical electrodynamics. Frisch was certainly showing an inconsistency in something; and Belot and Muller certainly had good reason to claim consistency for something else.

That was the whole problem. They were making claims about different things. It was rather like watching a heated debate over whether there are good croissants in Paris, only to find that one combatant is talking about Paris, France, and the other Paris, Arkansas.

What dissolved this debate was the simple realization that we should stop talking about theories and focus our attention on the particular set of assumptions at issue. If we do that, the debate just dies. There's nothing left to dispute since all parties agree on the consistency of the various explicit sets.

It was not just this particular debate that dissolved, Pete noticed. The same thing happened with other cases of inconsistency that he investigated in his dissertation.

The proposal Pete presented today was to take this idea and apply it to still more debates. We are to stop talking of theory in general or of particular theories like Newtonian physics or classical electrodynamics. We are instead to talk about a collection of assumptions that we establish to be interesting or important; and then we explore the collection's properties.

Would this really work on other examples? Pete had another case. Whether Newtonian mechanics is indeterministic has roused passions lately. I should carry some blame for the fuss for my cooking up of an example, the "dome," that generated indeterminism in a system that seems just too simple. Mark Wilson had responded with thoughts that Pete found ran along the lines of his own thinking; and now Mark too was sitting in this audience.

There was much more to be said. The proposal was to do away with an idea that has long been central to philosophy of science. Pete put some effort into showing the problems faced if we try to retain the notion of theory in the cases at hand. Still, he was urging drastic surgery and my sense was that this audience would be eager to offer second opinions.

The room was pretty full. At the break in a talk before question time, there is usually a quiet exodus. I couldn't help noticing that there was less of it. This group was sticking around for the discussion. Before the first question was asked, I had ten names in the queue.

After it was all over, I left Mark and Pete in earnest discussion. It was sufficiently intense that Pete forgot to take his umbrella with him. It ended up hanging on the door of his office, when he had taken off for a late lunch and more discussion.

John D. Norton