Sunday, July 1, 2018

Science and Philosophy

I stumbled onto a very interesting article about a scientist, Michela Massimi, who was making waves by promoting the idea that philosophy has an important role in science.  It seems fairly obvious to me, but I don't work in science so my perspective is very different.  Then again, I also felt that philosophy had an obvious role in history, and many historians don't.  It often seems that way as long as you're taking some of the fundamental things for granted, but the moment they become questioned, you need philosophy to help you out.

The interesting thing is not just that Massimi defends philosophy, but that she takes a contrarian view that science is actually closely related to physical reality.  This probably seems to most people like a silly thing to debate, but it is a major issue in philosophy.  Do scientists describe what actually happens, or do they just give us a model that can account for what happens but bears no actual relation to what is going on?  In the interview, Massimi makes an indirect reference to Thomas Kuhn, whom I discussed way back in the early days of this blog.  She doesn't mention Kuhn, but she mentions his major case study, which is the Copernican revolution.  Everyone knows that Copernicus showed how the earth revolves around the sun rather than vice versa, but what most people don't know is that the old geocentric model was capable of explaining the motions of the planets very well.  It had to make some assumptions, such as the idea that a planet could trace out a smaller circle on its path in a large circle around the earth.  (This is known as an epicycle; for a longer explanation, and a nice visual aid, see this wikipedia article.)  It got rather complicated once you included the epicycles in planetary motion, but the geocentric model could account for all the observed motions of the planets with great accuracy.  Copernicus's model of planetary motion wasn't more accurate in predicting where planets would go, but it was a lot simpler, and he felt that simpler was better.

Massimi mentions the debate between the two world views as a case where science could explain the observable phenomena in two different ways, and no one could confirm which was correct, if either.  For Kuhn, the important fact is that astronomers before Copernicus had come up with a detailed explanation for planetary motion that had predictive value, but which was in fact wrong.  And we can never be sure that any of our (admittedly much more sophisticated) models and equations explanining physicial phenomena are not perfectly accurate but, like the geocentric model, incorrect descriptions of reality.

I have always found this a strange debate because we know, in fact, that Copernicus was right.  We can say that the geocentrists were wrong precisely because we have been able to observe things with so much more accuracy that we are now certain that the sun and planets do not revolve around the earth.  Moreover, we are not going to discover at some point in the future that the geocentrists were right all along and the earth really is the center of the universe, at least not in the sense they meant it.  We may discover that Copernicus's model was not totally accurate.  In fact, that is exactly what happened later in the century when Kepler showed that planets' orbits are elliptical rather than circular.  But that discovery was a refinement, not a contradiction, of Copernicus's ideas.  Copernicus was closer to explaning physical reality than the geocentrists, even if he didn't get everything exactly right.

Massimi comes down on the same side I do, saying that science is indeed a reflection of physical reality.  She has coined her own position, which she calls "perspectival realism," which she describes as follows:  "We cannot be content with just saving the observable phenomena and producing theories that account for the available evidence [i.e., like the geocentric astronomers]. Yet it acknowledges that scientists don’t have a God’s-eye view of nature."  And by her qualification of not having a "God's-eye view," I take it she means that we can't be sure that we're right because we can't know the essence of physical phenomena, only what we can observe.

In other words, Massimi is essentially adopting Kant's transcendental idealist and empirical realist position, which is a fancy way of saying that we can get closer, in practice, to explaining obersvable phenomena in nature, but we can't ever know for sure the essence of things.  "Perspectival" seems to emphasize that we interact with the world through our senses and all the background assumptions that make when we use them; "realism" suggests that there really is something behind our perceptions.  She seems to be making less of a firm distinction between the idealist and realist positions adopted by Kant, the opposite direction from Schopenhauer and other German idealists who took the transcendental idealist view and built it up to the equivalent of saying that we have no interaction with the "real" world at all, that perceptions are all we have and they bear no obvious relation to anything that might be "behind" them in reality.  As I wrote in my discussion of Schopenhauer's "The World As Will and Idea," I think this extreme idealist position is not logically required and indeed is basically refuted by the pragmatist argument of Charles Peirce, which asks, "what do you really believe, to the point that you are willing to act on it?"  And we all pretty much act as though our perceptions were more or less closely associated with reality.