01 September 2011

Daniel Dennett's The Intentional Stance

The Intentional Stance

I recently finished reading Daniel Dennett's The Intentional Stance. It is more or less a collection of his early articles about the intentional stance, with some editing for cohesion.

It's a pretty slow read; just 350 pages but his prose requires careful attention. I found it worth the time. He actually explains the main idea in the first few pages. Dennett has never been one of those philosophers who talks for a dozen chapters before he gets to his real ideas.

Roughly speaking, he defines three levels of analysis:

  • The physical stance. All things are made up of physical material (atoms and molecules, usually) and obey physical laws. This applies to anything.
  • The design stance. Some things behave as though selected for a particular purpose. This applies to artifacts and products of evolution - things that are designed, whether by "real" designers or blindly by evolution.
  • The Intentional Stance. Some things behave as if they held beliefs and goals. This stance applies to intelligent living things.

He then defends why stances other than the physical should even be needed or useful. Roughly, because they predict so well from sparse data.

Dennett gives the example that, given the phone call "Honey, could you pick up a gallon of milk on the way home?", we can predict a very high likelihood that some ten or twenty minutes later, the man on the phone will drive a car into the driveway and enter the house carrying a gallon of milk (with some assumptions by context, eg assuming they have a driveway). A "martian" who uses exclusively the physical stance might make the same prediction by number-crunching through an overwhelming deluge of physical data, laboriously calculating the non-collision of the man's vehicle with other vehicles at intersections and so forth. But obviously the martian is doing it the hard way.

On mistakes

In "Making Sense Of Ourselves" and "When Frogs (and others) Make Mistakes", he considers the intentional stance when agents make mistakes. By which he means acknowledged mental failures, like a boy who sells lemonade for $0.12 giving a customer $0.11 change for a quarter. He didn't think that 11 + 12 = 25 and he wasn't trying to steal $0.02, he just made a mistake.

Dennett finds, roughly, that mistakes are gaps in the applicability of the intentional stance, much like the design stance will fail to predict when a broken alarm clock will ring. And he find that the intentional stance remains viable nonetheless, just as the design stance remains useful even if some alarm clocks do break.

Interesting quote on a side-topic:

[Quine] has been unable to give a detailed and realistic example, not because his thesis is false but because it postulates the possibility of a case poised on a knife-edge - two [possibilities] such that all the available relevant information fails to favor one over the other. The actual world abhors knife-edges even more than vaccuums. Almost inevitably grubby details begin to mount faster on one side than the other [. . .]

Beyond Belief

In "Beyond Belief", the longest chapter, Dennett takes issue with the "propositional attitudes" model and finds that what we have beliefs about are not objects in the real world, but notional objects. The notional objects are nevertheless generally tightly bound to real objects.

He also takes issue with the de dicto / de re dichotomy. He gives the example of a prank that he contemplated as a youth but never actually committed. There were two very nearly identical restaurants, and the prank would have been to have dinner with his friends at one restaurant, slip one of his friends a mickey, and drive him to the identical other restaurant, arranging everything identically. Thus the status of all of his friend's beliefs about "the restaurant" would be sensitive to whether they were about "the restaurant I'm in" or "the restaurant I went to tonight".

Dennett also uses the example of a belief about "the shortest spy in the KGB". This of course refers to an actual person (given that there are no exact ties and at least one KGB spy), yet the actual person is practically undiscoverable. Consider the belief that this person is female. The truth value of this belief can change from moment to moment as the KGB roster secretly changes, and without any "ordinary" change in the believer. Dennett borrows Geach's term "Cambridge change" to describe this sort of change, "like that change that befalls you when you suddenly cease to have the property of being closer to the north pole than the oldest plumber born in Utah"

Building on these examples, Dennett makes a persuasive argument that the de dicto / de re dichotomy misses something crucial. ISTM de dicto and de re still remain useful shorthands, as long as one that they abbreviate a potentially more complex situation.

Intentional systems in cognitive ethology / Interpreting Monkeys, Theorists, and Genes

He reviews some experiments on vervet monkeys - civilized experiments, I want you to know, like playing fake monkey alarm calls and seeing how the other monkeys react. He proposes that we should design experiments with an eye on the intentional stance.

He also takes issue with Lewontin and Gould's stance against "adaptionism" and "The Panglossian Paradigm", finding that they have more in common with B F Skinner than they think.

Another great quote on a side-topic, this time in a footnote and borrowed from Kahnemann:

I shall always treasure the visual memory of a very angry philosopher, trying to convince an audience that `if you believe that A and you believe that if A then B, then you must believe that B'. I don't know whether he had the moral power to coerce anyone to believe that B, but a failure to comply does make it quite difficult to use the word `belief', and that is worth shouting about.


In "Error, Evolution, and Intentionality" he largely revisits themes from the earlier chapters. Apparently other philosophers had misunderstood him, and he is clarifying himself and rebutting them.

Sometimes it takes years of debate for philosophers to discover what it is they really disagree about. Sometimes they talk past each other in a long series of books and articles, never guessing at the root disagreement that divides them. But occasionally a day comes when something happens to coax the cat out of the bag. "Aha!" one philosopher exlaims to another, "so that's why you've been disagreeing with me, misunderstanding me, resisting my conclusions, puzzling me all these years!"

There's enough new material here that I don't think I wasted my time, but it doesn't lend itself to much of a summary other than "largely revisits".

Fast Thinking

This chapter is somewhat anomalous for this book. Here Dennett opines that maybe slow AI isn't AI at all, because thinking fast enough to keep up with events as they happen is a crucial part of intelligence.

Mid-term examination

Largely his thoughts on philosophy "as she is done". This is the first time I've seen Dennett address this subject. Sometimes I have thought that he must be awfully frustrated with some of his fellow philosophers, who seem to misunderstand points that this layman easily grasps. But he tackles the subject without a cross word.

Priority squabbles [. . .] in philosophy [. . .] tend to take on the air of disputes among sailors about who gets credit for first noticing that the breeze has come up

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