My four courses have come together this week more than usual. In Intro we're reading Bertrand Russell's version of the argument by analogy for other minds and Ryle's "ghost in the machine" rejoinder, in Epistemology we're reading Thomas Nagel's The View From Nowhere, but at the moment we've detoured to reading Nagel's "What is it Like to Be a Bat" article and Frank Jackson's "What Mary Didn't Know," and that led us on to David Lewis, "Mad Pain and Martian Pain." So the six of us are trying to figure that article out. In Contemporary we're reading Kenny's chapter on philosophy of mind, which covers Bentham vs. Kant, psychoanalysis, and the Tractatus. And in Philosophy of Psychology we're moving out into Braddon-Mitchell and Jackson's Philosophy of Mind and Cognition, finishing Part One explaining "commonsense functionalism," the view they espouse.
So I was struck by the article in today's NYT "Smaller Version of the Solar System Is Discovered," which turns out to be an excellent illustration of functionalism's advantage over reductive materialism, in addition to being philosophically significant in itself. In our age we're used to physics and biology being philosophically significant sciences, but for much of the history of the modern world astronomy has been seen as posing as great a threat to established ideas as, say, evolutionary biology or big bang theory is seen today. The culture that existed before Copernicus, Kepler and Galileo displaced humans from the center of the universe is not the same culture afterwards. This process continued during the 20th century, when Hubble showed that our Milky Way Galaxy is only one of a great many galaxies, and recent observations with the Hubble Space Telescope have caused the estimation of the number of galaxies to be greatly increased. Meanwhile we have seen through spectroscopy, for example, that the natural processes that we observe on Earth, as well as other constants such as the distribution of elements, is apparently much the same in the rest of the universe as it is nearby. The right combination of common ingredients, between a heat source and a heat sink, will start forming the "primal soup," protein chains out of which organic life is built up. The universe is full of life to a mathematical certainty; it's not rational not to believe it. Since 1995, over 250 exoplanets (planets in orbit around stars other than our own) have been discovered, using the wobble effect (the gravitational pull of a massive satellite observed as a tidal pulse on the star surface). Now a new technique called microlensing exploits the refraction caused by one object's gravity bending the light from a more distant object. Today's story informs us, among other things, that the number of nearby stars with planets seems greater than had generally been imagined, and that systems with gaps where temperate, Earth-sized planets might be are being observed.
One type of functionalism is a kind of non-reductive materialism: every token of a mind is a token of a physical thing as well, but mental types supervene on physical types (multiple physical types can realize the same mental type). So psychology doesn't just analyze down into the physical understanding of human nervous systems. To see the point think of the exobiologists: their job is to think about what exoorganisms might be like, what they must be like, what they can't be like, and so forth. The magic of it, as someone else said somewhere, will not be just in the differences or just in the similarities. The magic will be the blend of similarity and difference. Exobiology suggests exopsychology. Functionalism aspires to be a kind of exopsychology: what must be true of a thing in order for it to come under psychological description? What defines the set of "persons"?