Donald Davidson

Donald Davidson

Donald Davidson, the philosopher of mind and language at Berkeley, died yesterday. This makes the second giant of philosophy -- especially of my particular philosophical experience -- to die in the last 12 months. Rawls passed away earlier this year while I was in France. As a major figure of the canon of political philosophy, he was on the front page of the Times and many papers. Donald Davidson, though, was a philosopher's philosopher at the heart of the tumultuous "linguistic turn" of 20th century philosophy. The big advances in this century were not in ethics or political thinking, they were in understanding the role of talking and thinking themselves.

It's up to you to decide what the big advances of the last century were, not me, but I'll continue giving you my humble opinion.

When Williams James at Harvard and John Dewey at Columbia were pushing the pragmatist agenda in the early 1900s, they were moving in a current that advanced thinking about the mind. The first formal study of psychology was solidifying its sometimes strange results and the agenda for philosophy of mind became urgent. James was into all kinds of strange things, like séances and mindreading, but the future held a series of a crises around the issue of mind and body: how can the physical sciences explain everything if the mind is not a mere physical thing? And if the mind is a physical thing, how can the mind be as free and powerful as we thought it should be? A later Harvard professor named B. F. Skinner claimed to have captured the mind on a page of formulas, precise and empirical relationships between inputs and outputs.

Meanwhile, a European line of inquiry from the late 19th century sought to formalize with the precision of mathematics that most essential discipline: reason itself. If we can organize and precisely study the structure of mathematics, why can't we do the same for arguments and reasoning itself? We should know the truth of an argument from its pure and unsullied structure. Formal logic's father was Frege and its famous pioneers for anglophone philosophy were Whitehead and Russell. While philosophy was typically conducted in ordinary sentences (as hard as they sometimes were to understand) the dream of people inspired by Russell and Frege was to create a philosophy that was perfectly formal: If P and P-->Q, then Q. Stuff a computer could check.

Indeed, computers were being built to operate in precisely this fashion, and a result of this line of research was Turing's test for when a computer had successfully implemented a mind. In fact the underlying assumption is more than just a test; it is an argument that a computer can implement a mind as surely as it implements any complex program code. (The Church-Turing thesis. You can also look at Chapter 1 and 3 of my dissertation.)

A computer is a machine that operates observing the complex formal instructions of its programs, languages that were designed following from the developments of Frege's "calculus" for logic. And a computer running such a language can implement a mind. A computer can be a mind. (Maybe every computer is always a mind, where some minds--like ours--are smarter than others.)

I'm being rather informal here, but the main idea is that language and mind were important top-level currents in 20th Century philosophy through war.

When Davidson arrived at Harvard, studying with the great W.V.O. Quine (who died in 2000), he was on to be influenced by the important arguments of the 1950s against logical positivism and empiricism. Essentially, the move began against the view that language could be made like logic. The logical positivists thought that we could avoid nonsense sentences and stick to simple stuff, like "This snow is white." Adding some logic to build up such little sentences into big theories (like "All snow is white."), we could make logical language the building block of careful science. Quine and Davidson pushed a campaign against this view.

It's folly to think you can ever be careful or precise enough to achieve the purity of mathematical precision. Complex sentences can't simply be broken down into simple ones like "this snow is white". Nor can we distinguish sharply between the observed facts and the "logical" language. Sometimes the logical language is just as much up for debate or disagreement as the observations -- neither is pure or precise. In fact, Davidson seemed to push this further. He argued that it is silly to say that there is some "mental picture" on the one hand and there is some actual reality on the other hand. The very idea that science is about getting our mental picture to be faithful to reality just sets us up to fail.

That's why Richard Rorty at Stanford, the dean of American Pragmatism, loves to group Davidson with Derrida and Wittgenstein. Very different figures! It's a provocative grouping that usually annoys philosophers in philosophy departments. It sure annoys the guys in the Stanford department. But he's talking about something that any undergraduate can appreciate: all these guys think language and the things we say are separate from the "world". They don't have to match and there's no way to know if they do. Language has its own internal rules, roughly, and figuring out what people mean depends on what you think they mean or what they could possibly mean. It doesn't depend on the specific chemical structure of some tiny particle. "Reality" is obscure and pretty much irrelevant to these guys. We all decide what's true or false using what we think is good evidence.

Davidson's work was in language and mind. I ran into this language stuff as an undergraduate when I studied with Akeel Bilgrami at Columbia, himself a student of Davidson's and a solid Davidsonian. He got me thinking Davidson might be right about meaning -- it's not the apple in the bowl that tells us what "apple" means, it's what I'm thinking when I say apple. It's what I mean by "apple". You see perhaps how this technical argument in the philosophy of language connects with Rorty's point about truth. You can judge my sentence "All apples are red" without knowing what I mean, even if you already see a green apple in the bowl.

I read the mind stuff at Stanford, with another Davidson student, Michael Bratman. The gist of Davidson's idea was to say that our mental life pretty much consists of our attitudes towards sentences. Well, it's not proprietary Davidson stuff. But this idea is the one wanted to work with to explain psychological questions. Why did Amol walk to the fridge? Because he believed a sandwich was in the fridge and desired to eat it. Two discrete attitudes, strict rules for how they interact, and bang! An action results. We can apply the rules of logic to understand the function of the mind, just as if it were a computer. Reasons are the causes of action just as the cue ball is the cause of another ball's motion.

I carried Davidson's picture (above) around in my wallet for about 4 years. So I figured he deserved some comment with his passing.