On 12/4 we spoke with David Chalmers about his new book, Constructing the World. Listen to the episode. The book explores a series of related positions that attempt to generalize and improve upon Carnap's project of logical construction in the Aufbau, the subject of our episode 67 (which will be posted soon).
Carnap's project was problematic mainly because first, it was excessively reductionist: we have no reason to think we can really recast all language about the physical world in terms of statements about our immediate experiences. We also (says Chalmers) certainly can't reduce all mental talk to physical talk (an effort that post-Aufbau Carnap was sympthetic to). Second, Carnap's technique of using definitions as the way to reinterpret one term in terms of another seems not to work, due to objections like Wittgenstein's against the classical view that any term can be defined using a set of necessary and sufficient conditions. It's very easy, when faced with most definitions of this sort, to come up with a counterexample that doesn't fit the definition.
Chalmers's solution comes out that very critique. If, for instance, I argue against your alleged definition of "chair" by coming up with an example that is a chair but isn't covered by your definition, to know that this counterexample works, i.e. that it's still a chair, I must be using information to do this that's still about a concept, but isn't definitional. We already have a word in philosophy that we can use here: "a priori," and Chalmers describes these facts about the concept as "scrutable" from our background knowledge. Scrutability expresses the ability of someone with requisite knowledge to figure out something else; the term is purposefully vague in saying how this is figured how, which means that Chalmers can talk about one piece of knowledge being based somehow on another piece without having to say that, for instance, one logically entails the other, which would then elicit the question of which logical rule allows that entailment.
Chalmers's generalized scrutability thesis is that all truths about the world are scrutable from some compact set of basic truths. His book then explores many different more specific versions of this: What kinds of truths get included in the base? How can we more specifically characterize the type of scrutability? Like Carnap, Chalmers isn't doing psychology. He isn't concerned with how we actually derive knowledge, but about the logical relations between different kinds of truths. But he's not quite doing straight-up metaphysics either. Though the resultant scrutability framework will describe "the structure of the world," e.g. it's supposed to say whether mental phenomena rest on physical phenomena or vice versa (Chalmers thinks neither; both physical and phenomenal truths need to be included in the base), it does so by analyzing our concepts.
You might think of this as the linguisitc, analytic version of of how the continental phenomenologists treat metaphysics: Given that we can't know the world in itself (from Kant), for a phenomenologist like Husserl, "ontology" becomes a description of the entities found by experience, or maybe the structure of experience itself, which is objective in that these structures are intersubjectively verifiable (mine seems the same as yours, insofar as we can confirm that by talking about it). For this breed of analytic philosophy (shared not only by Chalmers and Carnap, but also by Russell and Wittgenstein), ontology becomes conceptual analysis.
So Chalmers thinks that we can have a profitable discussion about what kinds of concepts are primitive, and so what kinds of knowledge would have to compose a scrutability base (e.g. maybe we need to know both all of the micro-physical facts, i.e. the positions and velocities of all the basic particles in space and time, as well as all of the basic phenomenal facts as Carnap starts with, plus logical apparatus and some other things), and everything else would then be derivable from that. Even without filling in the details or settling all the difficult issues involved, Chalmers thinks that this framework provides advantages in clarifying problems like the mind-body relation and gives us a non-spooky way of talking about something like Fregean senses (which I can't sum up in one sentence). So we pumped David about these supposed advantages and others.
For a concise (1 hr) introduction to the work, watch this lecture he gave on the project from December 2011:
Watch on YouTube.
For more detail (six lectures, with handouts!), download audio of the John Locke lectures Chalmers gave at Oxford in 2010. (iTunes U link)
For the full story, of course, you'll need to buy the book.
Chalmers is famous primarily because of his 1996 book, The Conscious Mind: In Search of a Fundamental Theory, where he argued for a form of property dualism in which consciousness, or more likely something like "proto-consciousness" is best conceived as a fundamental feature of the world, i.e. that whenever you have physical representation of information, then you have correlated with that what you might call a point of view from the standpoint of that information. He actually has a section entitled "What Is It Like to Be a Thermostat?" where he argues that some form of panpscyhism is at least not obviously absurd, and that the problems it introduces might be preferable to those raised by views that simply equate mind and body, or say that mind is reducible to body. That book contains many of the seeds of this one, and is definitely a better choice for those fairly new to reading philosophy texts. It also serves as a great introduction to issues in the philosophy of mind.
In preparation for this interview, I ran a Not School group that read selections from The Conscious Mind, and we held a six-person-discussion about it that, despite not being edited in the way that a normal episode is, came out according to one listener "almost as good as a PEL episode." You can go listen to this 90-minute audio right now if you become a PEL Citizen.