On scientific anti-realism
An email exchange with Noam Chomsky.-- Me: “I’m curious what you think about a subject that has always fascinated me, as it has many philosophers and scientists. Modern science teaches us that ‘secondary qualities’ [such as smell and color] do not inhere in external objects or ‘things in themselves,’ but that they are constructed by the brain through its manipulation of sensory data. The world we perceive is not the world in itself. I see a brown table, but ‘really’ what is out there are molecules, electromagnetic waves, etc., not the object I see. So, when I turn around, for example, and look somewhere else, the table is ‘gone’; what remain are the only elements that were always there, namely the colorless particles and waves that physics postulates. Thus, in a sense our brains are massively deceiving us, somewhat like Descartes’s demon, in causing us to think that the objects we perceive have real, mind-independent existence. The world in itself has almost nothing in common with the world we perceive.
“I don’t see any other way of interpreting modern science, but I’m curious if you disagree.”
Him: “Descartes would have pretty much agreed. His theory of perception was based on the idea that the internal structure of the perceptual system interacts with external data to determine what we perceive. Thus, to pick one of his examples, if I look at an audience in a talk, I perceive people, but I’m constructing that visual interpretation from very scattered and limited data, ideas that were developed significantly in the 17th century and beyond. I don’t see what alternative there is.”
All this seems profoundly obvious, but many philosophers have somehow managed to convince themselves that this “scientific realism”—which is surely the only view that can explain the success of science—is false. The logical positivists, for example, or earlier subjective idealists, or later postmodernists. These people aside, is it not astonishing that nature has, evidently, designed human brains to be so alike that each person perceives essentially the same world as every other? The brain conjures a magnificent three-dimensional, kaleidoscopic, ordered world out of the colorless chaos of nature-in-itself—and every brain conjures that same world! In other words, we’re basically copies of each other, with very marginal differences in “personal traits” and so on. We are truly miracles, and wonder is the most appropriate reaction to ourselves and our relation to the universe.
Another exchange, several years later.-- Me: "For a long time I've been bothered by the idea that I have to choose between two options: either philosophical idealists have been radically confused, or I radically misunderstand them. Neither option I find particularly satisfying, but I've been a bit more attracted to the first. In brief: when Berkeley or Schopenhauer or whoever says that he accepts natural science, but at the same time that there is no mind-independent matter, that the world exists solely in consciousness, so to speak, it seems to me he is blatantly contradicting himself. For science explains the phenomena that we experience in consciousness by postulating material processes that are supposed to be occurring external to consciousness, i.e., without consciousness's being aware of them as they're happening. Digestion is going on 'mind-independently.' And it's a material process. So: every scientific hypothesis is transparently, obviously premised on the notion that matter-external-to-consciousness exists. (And of course, in addition, the success of science is inexplicable except by presupposing scientific realism.) This seems to me so obvious, so necessarily clear to even an eight-year-old, that I'm bewildered as to how philosophers could fail to see it. Am I somehow misunderstanding them?
"I'd say something similar about the logical positivists, incidentally. They wanted to avoid metaphysical questions as being meaningless—questions like whether there is a 'world-in-itself,' a world of matter external to mind—somehow failing to see that when science describes, e.g., mechanisms internal to the brain, it is assuming that there is a brain, which is to say a piece of matter 'external' to mind. A piece of matter that, in fact, gives rise to mind. Lenin ridiculed Ernst Mach and others' "[literally] brainless philosophy" in Materialism and Empirio-Criticism [see here], and I have to admit I sympathized with his frustration when reading it. For it seemed clear to me that Mach and his logical positivist disciples were, despite themselves, effectively idealists (in their instrumentalism, etc.). In any case, thinkers like Carnap, who were in some respects very acute, should have seen that one cannot avoid "metaphysical" questions like whether matter exists (external to mind). It's either Yes or No, not "the question is meaningless." If Yes, science—the search for causes in the external world—is possible. If No, science is not possible. –But evidently it is possible, so the answer has to be Yes.
"Does this seem like approximately the right picture, or am I underestimating all these anti-realists?"
Him: "It’s possible to hold, consistently, that we can be confident only of our immediate experience/impressions, that science is our effort to try to account for them, and that contemporary science is our best guess—but without going beyond that to claim that the entities postulated are more than explanatory fictions. –I’m not advocating that, but it’s a consistent position."
So, the alternative to realism is that science explains the world we experience by suggesting fictional processes are going on between fictional entities. Not only are there no atoms, electrons, protons, etc.; there are also no biological cells, no internal organs, no bones, no things at all except when we're perceiving them. Food is digested by means of stomach acids and so forth, which don't exist. They're useful to talk about because they explain things....but they're fictional. --So how, then, do they explain things? It seems to me that this is contradictory, not to mention indescribably stupid.