Symbol Manipulation and Intentionality

Июль 27, 2022

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Symbol Manipulation and Intentionality

Содержание

2. Minds, Brains, and Programs Searle is addressing a few different but interconnected issues One is the
3. Terry Winograd’s SHRDLU (1971) Terry Winograd was a grad student at MIT whose dissertation project involved
4. original
5. colored rendering
6. SHRDLU could... Describe (when asked) what was in the world (e.g., is there a green triangle
7. conversation Person: WHICH CUBE IS SITTING ON THE TABLE? Computer: THE LARGE GREEN ONE WHICH SUPPORTS
8. you can see how predicate logic is useful here Person: IS THERE A LARGE BLOCK BEHIND
9. Roger Shank’s work Developed a software program that could answer simple questions about a story To
10. Did the man eat the hamburger?
11. We’re not told this information, but in the 1970s there was work on “case-based reasoning” by
12. Enthusiasts of AI thought we were starting to build computers that could think and understand.
13. This is very much related to the Turing Test
14. Alan Turing (1912-1954)
15. Alan Turing (1912-1954)
16. “Computing Machinery and Intelligence” (1950) Imagine you have one person who is asking questions of both
17. There’s been a good deal of discussion about what passing the Turing test would actually accomplish.
18. Daniel Dennett on a “great city”
19. a great city is one in which one can: have a nice French meal go to
20. Dennett’s point is that clearly we should take this as evidence for a city’s being great,
21. Let’s get to Searle’s Chinese Room
22. First, what is “intentionality”?
23. “aboutness” Comes from the Latin “intendere”, “to point at” E.g., your belief that there’s a staircase
24. And what is “functionalism”?
25. In the context of philosophy of mind, functionalism is the hypothesis/view that the materiality of the
26. And the idea here is that a neuron fires (or doesn’t) which influences the probability that
27. Often in cognitive science you here the mind described as “software” and the brain as “hardware”.
28. functionalism is controversial Most cognitive scientists endorse it (I think) Most people working on AI do,
29. Ned Block’s “Troubles with Functionalism” (1978)
30. The China Brain Thought Experiment No relationship to the Chinese Room, aside from being another thought
31. Suppose that China has 100 billion people, and that we give each person a little hand-held
32. Ned Block says clearly it will not. So he believes functionalism is false.
33. What’s the difference between “strong” and “weak” AI?
34. Roughly... weak AI just uses computers to help us understand how the mind works strong AI
35. The Chinese Room Searle (who knows no Chinese) is locked in a room He has a
36. The Chinese Room
37. Searle’s Conclusions Instantiating a computer program is not sufficient for intentionality After all, Searle instantiates the
38. Searle’s Conclusions (2) Functionalism is implausible Functionalism says that what matters are the functional relationships between
39. Searle’s Conclusions (2*) Strong AI is implausible Strong AI is predicated on functionalism, and functionalism is
40. Important to note Searle does not say that machines can’t think. Indeed, he says the brain
41. A few things to note There’s a reading of Searle (1980) according to which he’s really
42. the “systems reply” Perhaps Searle doesn’t know Chinese, but “the room” (i.e., the whole “system” does)
43. Dennett seems to have this response “Searle observes: ‘No one would suppose that we could produce
44. Dennett goes on... “[Searle] can't really view intentionality as a marvelous mental fluid, so what is
45. How does Searle respond?
46. “My response to the systems theory is quite simple: let the individual internalize all of these
47. the “robot reply” "Suppose we wrote a different kind of program from Schank's program. Suppose we
48. How does Searle respond?
49. But the answer to the robot reply is that the addition of such "perceptual" and "motor"
50. So does the Chinese Room thought experiment show that a computer could never “understand” human language?
52. Скачать презентацию

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Minds, Brains, and Programs
Searle is addressing a few different but interconnected

issues
One is the relationship between symbol manipulation and intentionality
Another is functionalism
Another is the difference between “strong AI” and “weak AI”
Another is work that was being done in artificial intelligence around the time the article was published
(Let’s look at this work first.)

Слайд 3

Terry Winograd’s SHRDLU (1971)
Terry Winograd was a grad student at MIT

whose dissertation project involved creating a “blocks world” (i.e., a small, digital world of shapes)
A human user, using natural language expressions, could ask the computer about the world and could command the computer to manipulate the world

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original

Слайд 5

colored rendering

Слайд 6

SHRDLU could...
Describe (when asked) what was in the world (e.g., is

there a green triangle on top of a box)
Move things around (e.g., put a triangle on a box)
Answer questions about what was possible or not (e.g., can you put a triangle on a triangle?)

Слайд 7

conversation
Person: WHICH CUBE IS SITTING ON THE TABLE?
Computer: THE LARGE GREEN ONE WHICH

SUPPORTS THE RED PYRAMID.
Person: IS THERE A LARGE BLOCK BEHIND A PYRAMID?
Computer: YES, THREE OF THEM: A LARGE RED ONE, A LARGE GREEN CUBE, AND THE BLUE ONE.
Person: PUT A SMALL ONE ONTO THE GREEN CUBE WHICH SUPPORTS A PYRAMID.
Computer: OK. (does it)
Person: PUT THE LITTLEST PYRAMID ON TOP OF IT.
Computer: OK. (does it)

Слайд 8

you can see how predicate logic is useful here
Person: IS THERE A

LARGE BLOCK BEHIND A PYRAMID?
To answer the question, you ask whether the following is true: “There is a large block behind a pyramid.”
How would you translate that sentence into predicate logic?

Слайд 9

Roger Shank’s work
Developed a software program that could answer simple

questions about a story
To illustrate the issues, Searle gives the following example:
“A man went into a restaurant and ordered a hamburger. When the hamburger arrived it was burned to a crisp, and the man stormed out of the restaurant angrily, without paying for the hamburger or leaving a tip.”

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Did the man eat the hamburger?

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We’re not told this information, but in the 1970s there was

work on “case-based reasoning” by Roger Schank (and others) that allowed computers to answer questions like this.
In short, the program “knows” how a sequence of events would naturally unfold, and then might be cued in to deviations from that occurring.

Слайд 12

Enthusiasts of AI thought we were starting to build computers that

could think and understand.

Слайд 13

This is very much related to the Turing Test

Слайд 14

Alan Turing (1912-1954)

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Alan Turing (1912-1954)

Слайд 16

“Computing Machinery and Intelligence” (1950)
Imagine you have one person who is

asking questions of both a computer and a real person. (Variant of the “imitation game.”)
If the person asking the questions can’t tell which is the computer and which is the real person, then the computer passes there Turing test
(There are other formulations of the Turing test, but the basic idea is always the same.)

Слайд 17

There’s been a good deal of discussion about what passing the

Turing test would actually accomplish.
Is passing the test really sufficient for saying a machine can think?
There is also the charge of operationalism here, that is, to “think” is just to be capable of passing the Turing test

Слайд 18

Daniel Dennett on a “great city”

Слайд 19

a great city is one in which one can:
have a nice

French meal
go to the opera
see a Rembrandt

Слайд 20

Dennett’s point is that clearly we should take this as evidence

for a city’s being great, not a definition of a city’s being great
After all, we could have a city with one Rembrandt, one French chef, and one orchestra, but is terrible otherwise (e.g., in the midst of a civil war, disease outbreaks, looting, etc.)

Слайд 21

Let’s get to Searle’s Chinese Room

Слайд 22

First, what is “intentionality”?

Слайд 23

“aboutness”
Comes from the Latin “intendere”, “to point at”
E.g., your belief that

there’s a staircase outside the door has intentionality because it is about something, namely, the staircase
Beliefs, desires, and goals have intentionality
Not all mental states do (e.g., undirected anxiety, depression)

Слайд 24

And what is “functionalism”?

Слайд 25

In the context of philosophy of mind, functionalism is the hypothesis/view

that the materiality of the brain is not essential to cognition
That is, if diodes (or beer cans, water pipes, whatever) were arranged in the correct way, and interacted in the correct way, then they could do everything that a brain does

Слайд 26

And the idea here is that a neuron fires (or doesn’t)

which influences the probability that some other neuron will fire (or won’t)
So if we replace each neuron in your brain with any object that fired (or didn’t) and influenced whether some other object would fire (or not), then it would replicate the thinking, and experience, of your own brain

Слайд 27

Often in cognitive science you here the mind described as “software”

and the brain as “hardware”.
A functionalist believes that what the hardware is made out of is unimportant; all that matters is what it does.

Слайд 28

functionalism is controversial
Most cognitive scientists endorse it (I think)
Most people working

on AI do, too
With philosophers of mind, it’s mixed (e.g., Searle clearly rejects it)

Слайд 29

Ned Block’s “Troubles with Functionalism” (1978)

Слайд 30

The China Brain Thought Experiment
No relationship to the Chinese Room, aside

from being another thought experiment against functionalism
China was chosen because it has the biggest population of any country on earth
This isn’t exactly how Block’s thought experiment worked, but it’s more relevant to the present discussion...

Слайд 31

Suppose that China has 100 billion people, and that we give

each person a little hand-held machine that beeps when you press a button. And we also hook up electrodes to each neuron in some person’s brain (mine, say) and measure whether that neuron is firing or not over the course of 5 seconds. Over that 5 second period, I will of course have some phenomenal (i.e., subjective) experience. If we instruct the population of China to mimic the firing of my neurons with their little machines, will the nation of China have the same phenomenal experience I had?

Слайд 32

Ned Block says clearly it will not. So he believes functionalism

is false.

Слайд 33

What’s the difference between “strong” and “weak” AI?

Слайд 34

Roughly...
weak AI just uses computers to help us understand how the

mind works
strong AI is the idea that computers can actually think, understand, or experience in the way that humans can

Слайд 35

The Chinese Room
Searle (who knows no Chinese) is locked in a

room
He has a bunch of Chinese symbols and a rule book (written in English) that tells him how to match certain Chinese symbols with others.
Someone puts Chinese symbols into the room, he checks the rule book for how to respond, then produces a response.

Слайд 36

The Chinese Room

Слайд 37

Searle’s Conclusions
Instantiating a computer program is not sufficient for intentionality
After

all, Searle instantiates the program, but he does not know what the Chinese symbols mean. For him, the Chinese symbols are not “about” anything.
(In this context, we can really treat “intentionality” and “understanding” as synonymous.)

Слайд 38

Searle’s Conclusions
(2) Functionalism is implausible
Functionalism says that what matters are the

functional relationships between the parts of a system, not their materiality. But since Searle, by merely by running this program, doesn’t know Chinese, the materiality of the brain must matter.

Слайд 39

Searle’s Conclusions
(2*) Strong AI is implausible
Strong AI is predicated on functionalism,

and functionalism is implausible, for the reasons given in the previous slide.

Слайд 40

Important to note
Searle does not say that machines can’t think.
Indeed, he

says the brain is a machine and can surely think.
Rather, he says that a machine has to be sufficiently like the brain in order to think.
See p. 422

Слайд 41

A few things to note
There’s a reading of Searle (1980) according

to which he’s really refuting behaviorism, the idea that what it is to know Chinese (say) is to produce appropriate responses to stimuli.
Or another reading is that Searle (1980) simply shows that passing the Turing Test should not be treated as a sufficient condition for determining whether a machine can think.

Слайд 42

the “systems reply”
Perhaps Searle doesn’t know Chinese, but “the room” (i.e.,

the whole “system” does)

Слайд 43

Dennett seems to have this response
“Searle observes: ‘No one would suppose

that we could produce milk and sugar by running a computer simulation of the formal sequences in lactation and photosynthesis, but where the mind is concerned many people are willing to believe in such a miracle.’ I don't think this is just a curious illustration of Searle's vision; I think it vividly expresses the feature that most radically distinguishes his view from the prevailing winds of doctrine. For Searle, intentionality is rather like a wonderful substance secreted by the brain the way the pancreas secretes insulin. Brains produce intentionality, he says, whereas other objects, such as computer programs, do not, even if they happen to be designed to mimic the input-output behavior of (some) brain.”

Слайд 44

Dennett goes on...
“[Searle] can't really view intentionality as a marvelous mental

fluid, so what is he trying to get at? I think his concern with internal properties of control systems is a misconceived attempt to capture the interior point of view of a conscious agent. He does not see how any mere computer, chopping away at a formal program, could harbor such a point of view. But that is because he is looking too deep. It is just as mysterious if we peer into the synapse-filled jungles of the brain and wonder where consciousness is hiding. It is not at that level of description that a proper subject of consciousness will be found. That is the systems reply, which Searle does not yet see to be a step in the right direction away from his updated version of elan vital”.

Слайд 45

How does Searle respond?

Слайд 46

“My response to the systems theory is quite simple: let the

individual internalize all of these elements of the system. He memorizes the rules in the ledger and the data banks of Chinese symbols, and he does all the calculations in his head. The individual then incorporates the entire system. There isn't anything at all to the system that he does not encompass. We can even get rid of the room and suppose he works outdoors. All the same, he understands nothing of the Chinese, and a fortiori neither does the system, because there isn't anything in the system that isn't in him” (419).

Слайд 47

the “robot reply”
"Suppose we wrote a different kind of program

from Schank's program. Suppose we put a computer inside a robot, and this computer would not just take in formal symbols as input and give out formal symbols as output, but rather would actually operate the robot in such a way that the robot does something very much like perceiving, walking, moving about, hammering nails, eating, drinking - anything you like. The robot would, for example, have a television camera attached to it that enabled it to 'see,’ it would have arms and legs that enabled it to 'act,' and all of this would be controlled by its computer 'brain.' Such a robot would, unlike Schank's computer, have genuine understanding and other mental states” (p. 420)

Слайд 48

How does Searle respond?

Слайд 49

But the answer to the robot reply is that the addition

of such "perceptual" and "motor" capacities adds nothing by way of understanding, in particular, or intentionality, in general, to Schank's original program. To see this, notice that the same thought experiment applies to the robot case. Suppose that instead of the computer inside the robot, you put me inside the room and, as in the original Chinese case, you give me more Chinese symbols with more instructions in English for matching Chinese symbols to Chinese symbols and feeding back Chinese symbols to the outside. Suppose, unknown to me, some of the Chinese symbols that come to me come from a television camera attached to the robot and other Chinese symbols that I am giving out serve to make the motors inside the robot move the robot's legs or arms. It is important to emphasize that all I am doing is manipulating formal symbols: I know none of these other facts. I am receiving "information" from the robot’s "perceptual" apparatus, and I am giving out "instructions" to its motor apparatus without knowing either of these facts. I am the robot's homunculus, but unlike the traditional homunculus, I don't know what's going on.

Слайд 50

So does the Chinese Room thought experiment show that a computer

could never “understand” human language?

Symbol Manipulation and Intentionality

Содержание

Minds, Brains, and ProgramsSearle is addressing a few different but interconnected

Terry Winograd’s SHRDLU (1971)Terry Winograd was a grad student at MIT

original

colored rendering

SHRDLU could...Describe (when asked) what was in the world (e.g., is

conversationPerson: WHICH CUBE IS SITTING ON THE TABLE?Computer: THE LARGE GREEN ONE WHICH

you can see how predicate logic is useful herePerson: IS THERE A

Roger Shank’s work Developed a software program that could answer simple

Did the man eat the hamburger?

We’re not told this information, but in the 1970s there was

Enthusiasts of AI thought we were starting to build computers that

This is very much related to the Turing Test

Alan Turing (1912-1954)

Alan Turing (1912-1954)

“Computing Machinery and Intelligence” (1950)Imagine you have one person who is

There’s been a good deal of discussion about what passing the

Daniel Dennett on a “great city”

a great city is one in which one can:have a nice

Dennett’s point is that clearly we should take this as evidence

Let’s get to Searle’s Chinese Room

First, what is “intentionality”?

“aboutness”Comes from the Latin “intendere”, “to point at”E.g., your belief that

And what is “functionalism”?

In the context of philosophy of mind, functionalism is the hypothesis/view

And the idea here is that a neuron fires (or doesn’t)

Often in cognitive science you here the mind described as “software”

functionalism is controversialMost cognitive scientists endorse it (I think)Most people working

Ned Block’s “Troubles with Functionalism” (1978)

The China Brain Thought ExperimentNo relationship to the Chinese Room, aside

Suppose that China has 100 billion people, and that we give

Ned Block says clearly it will not. So he believes functionalism

What’s the difference between “strong” and “weak” AI?

Roughly...weak AI just uses computers to help us understand how the

The Chinese RoomSearle (who knows no Chinese) is locked in a

The Chinese Room

Searle’s ConclusionsInstantiating a computer program is not sufficient for intentionality After

Searle’s Conclusions(2) Functionalism is implausibleFunctionalism says that what matters are the

Searle’s Conclusions(2*) Strong AI is implausibleStrong AI is predicated on functionalism,

Important to noteSearle does not say that machines can’t think.Indeed, he

A few things to noteThere’s a reading of Searle (1980) according

the “systems reply”Perhaps Searle doesn’t know Chinese, but “the room” (i.e.,

Dennett seems to have this response“Searle observes: ‘No one would suppose

Dennett goes on...“[Searle] can't really view intentionality as a marvelous mental

How does Searle respond?

“My response to the systems theory is quite simple: let the

the “robot reply” "Suppose we wrote a different kind of program

How does Searle respond?

But the answer to the robot reply is that the addition

So does the Chinese Room thought experiment show that a computer

Похожие презентации

Minds, Brains, and Programs
Searle is addressing a few different but interconnected

Terry Winograd’s SHRDLU (1971)
Terry Winograd was a grad student at MIT

SHRDLU could...
Describe (when asked) what was in the world (e.g., is

conversation
Person: WHICH CUBE IS SITTING ON THE TABLE?
Computer: THE LARGE GREEN ONE WHICH

you can see how predicate logic is useful here
Person: IS THERE A

Roger Shank’s work
Developed a software program that could answer simple

“Computing Machinery and Intelligence” (1950)
Imagine you have one person who is

a great city is one in which one can:
have a nice

“aboutness”
Comes from the Latin “intendere”, “to point at”
E.g., your belief that

functionalism is controversial
Most cognitive scientists endorse it (I think)
Most people working

The China Brain Thought Experiment
No relationship to the Chinese Room, aside

Roughly...
weak AI just uses computers to help us understand how the

The Chinese Room
Searle (who knows no Chinese) is locked in a

Searle’s Conclusions
Instantiating a computer program is not sufficient for intentionality
After

Searle’s Conclusions
(2) Functionalism is implausible
Functionalism says that what matters are the

Searle’s Conclusions
(2*) Strong AI is implausible
Strong AI is predicated on functionalism,

Important to note
Searle does not say that machines can’t think.
Indeed, he

A few things to note
There’s a reading of Searle (1980) according

the “systems reply”
Perhaps Searle doesn’t know Chinese, but “the room” (i.e.,

Dennett seems to have this response
“Searle observes: ‘No one would suppose

Dennett goes on...
“[Searle] can't really view intentionality as a marvelous mental

the “robot reply”
"Suppose we wrote a different kind of program