COMP217 – MINDS and MACHINES
Introduction
The aim of this course is to introduce students to some of the fundamental philosophical approaches to mind, and to relate them to discussions concerning the nature and possibility of intelligent machines.
Because philosophy is best learnt through discussion, reading and writing – and, of course, thinking during these activities – the format of the module will differ from the standard lecture and practical format.
Topics will be addressed through
Position statements will not be assessed in weeks 1 and 12. The other ten position statements will be assessed, each contributing 5% of the mark for the module. The remaining 50% of the marks for the module will be on the basis of an examination. The examination will be a two hour exam comprising a number of essay questions, of which the students will be required to answer two.
The main text for 2006-7 will be E.J. Lowe, An Introduction of the Philosophy of Mind, Cambridge University Press, 2000. Other readings will be, where possible, available on the WWW, or in handouts.
Links
to General Sources
There are a number of good general dictionaries and encyclopaedias of Philosophy and Philosophy of Mind on the internet. A selection of links are:
Stanford Encyclopaedia of Philosophy
Routledge Encyclopedia Philospohphy of Mind
http://www.rep.routledge.com/?authstatuscode=200
Dictionary of the Philosophy of Mind
http://artsci.wustl.edu/~philos/MindDict/dictindex.html
Wikipedia
http://en.wikipedia.org/wiki/Philosophy_of_mind
Field Guide
http://host.uniroma3.it/progetti/kant/field/
SWIF Philosophy of Mind
http://lgxserver.uniba.it/lei/mind/index.htm
Garth Kemerling’s Philosophy pages
http://www.philosophypages.com/
Week
One
Minds and Bodies, People and Machines
Philosophy of Mind addresses the nature of mind and its relation to matter. But what is mind?, what kinds of things have minds? Are minds things than can be “had”?
In this first week we shall explore what we mean by “mind” and its relation to other concepts such as “intelligence”. Given the focus of our course we will give some preliminary consideration to the notion of mind in relation to machines.
Questions for discussion:
What is the relation between “mind” and “Intelligence” ? What does it mean to say something “has a mind”? Which of the following can “have minds”: people, spirits, children, animals, insects, plants, cars, computers, stones?
1
E.J. Lowe An Introduction of the Philosophy of Mind,
2 http://en.wikipedia.org/wiki/Mind .
3 For a classic discussion of mind, see Rene Descartes Meditations, Mediation 1 and, especially Meditation 2.
http://oregonstate.edu/instruct/phl302/texts/descartes/meditations/Meditation2.html
Week
Two
The Argument From Illusion
The argument from illusion is intended to place a gap between mental phenomena and the external world. It can be used as the basis of scepticism about the external world , or of solipsism (scepticism about the external world including other minds). Reactions to the argument can determine positions in philosophy of mind.
One formulation can be found in Descarte’s Meditations:
“But, afterward,
a wide experience by degrees sapped the faith I had reposed in my senses; for I
frequently observed that towers, which at a distance seemed round, appeared
square, when more closely viewed, and that colossal figures, raised on the
summits of these towers, looked like small statues, when viewed from the bottom
of them; and, in other instances without number, I also discovered error in
judgments founded on the external senses; and not only in those founded on the
external, but even in those that rested on the internal senses; for is there
aught more internal than pain? And yet I have sometimes been informed by
parties whose arm or leg had been amputated, that they still occasionally
seemed to feel pain in that part of the body which they had lost, --a
circumstance that led me to think that I could not be quite certain even that
any one of my members was affected when I felt pain in it. And to these grounds
of doubt I shortly afterward also added two others of very wide generality: the
first of them was that I believed I never perceived anything when awake which I
could not occasionally think I also perceived when asleep, and as I do not
believe that the ideas I seem to perceive in my sleep proceed from objects
external to me, I did not any more observe any ground for believing this of
such as I seem to perceive when awake; the second was that since I was as yet
ignorant of the author of my being or at least supposed myself to be so, I saw
nothing to prevent my having been so constituted by nature as that I should be
deceived even in matters that appeared to me to possess the greatest truth.
And, with respect to the grounds on which I had before been persuaded of the
existence of sensible objects, I had no great difficulty in finding suitable
answers to them; for as nature seemed to incline me to many things from which
reason made me averse, I thought that I ought not to confide much in its
teachings. And although the perceptions !of the senses were not dependent on my
will, I did not think that I ought on that ground to conclude that they
proceeded from things different from myself, since perhaps there might be found
in me some faculty, though hitherto unknown to me, which produced them.” Meditation 6:7
A more explicit formulation is:
(1) S’pose you are hallucinating a pink rat.
(2) Then you must be seeing something.
(3) But what you see corresponds to no external material object.
(4) Rather, it must be an internal, immaterial object. (a "sense datum")
(5) But your experience is the same as it would be, if you were really looking at a pink rat.
(6) So what it is that you see is the same in each case.
(7) So what it is when you are really looking at something (e.g., a pink rat), all you ever really see are immaterial sense data.
Dave Beisecker,
http://www.unlv.edu/faculty/beisecker/Courses/Phi-101/Phi101.html
Questions for Discussion: How convincing is the argument from illusion? If it is not convincing, what is wrong with it? Does it make a difference if we are looking at an illusion, a hallucination or simply a variable perception? Does it apply to computers? If so, how, and if not, why not?
http://www.disputatio.com/articls.html
Week
Three
Dualism
Dualism – the idea that mind and matter are distinct substances – is a long standing idea in the philosophy of mind. It is associated with Descartes, and Cartesian Dualism is a common form, although there are other varieties of dualism. A number of arguments have been proposed against it, but in many ways it remains an influential conception of mind.
Questions for Discussion
What are the arguments for Cartesian dualism? What other dualist positions are possible? What are the arguments against dualism? How could matter and mind interact? Does dualism exclude the possibility of thinking machines?
1. Lowe pp8 -38.
2. The General Sources e.g. Stanford Encyclopaedia of Philosophy article on Dualism
3. Thomas Nagel, “What is it like to be a bat?” http://members.aol.com/NeoNoetics/Nagel_Bat.html
4. http://www.philosophyonline.co.uk/pom/pom_non_cartesian_dualism.htm
Week Four
Materialist Theories of Mind
If we reject dualism we need to offer an account of how we attribute mental predicates to people, and how we account for the subjective experience of mental states. A number of theories have been advanced, including behaviourism, functionalism and identity theories. This week we will look at these approaches and consider whether they can adequately account for mental events.
Questions for Discussion
Can any of the materialist theories account for what we want to say about mental states? Can they account for our experience of mental sates? Is any of the materialist approaches more appealing than the others? Does adopting a materialist theory commit us to the possibility that computers have mental states?
Week
Five
Perception
In week 2 we looked at the argument from illusion, which was supposed to cast doubt on the reliability of our perceptions. This week we will consider a number of answers to the problem of perception, including causal, intentionalist and disjunctive theories. But, although seeing is often used as the paradigm of perceiving, we can perceive things using our other senses, and even without using senses at all, as when we perceive the truth of an idea. Is there more to perception than sensing? Do notions such as judgement and belief also play a role in perception?
Questions for Discussion
What is the problem of perception, and how well do the various theories of perception address it? When I see a mouse and hear a mouse do I perceive the same thing? When I perceive that a table is square does it matter whether I do so by sight or touch (or measurement?)? Are mental perceptions, such as the truth of an idea “real” perceptions, or this only an analogy? What is the role of judgement in perception? Does perception necessarily result in beliefs?
Week Six
Thought and Language
Among mental contents we generally assume there
to be “things” called thoughts, and thinking seems to be the paradigmatic
activity of an intelligent being. Thoughts seem to involve the combination of
concepts, and a mental attitude (belief, doubt, hope etc) directed towards this
combination. Descriptions of such thoughts are generally in sentences
expressing propositions, but it is not plausible to identify propositions
expressed in natural language with thoughts. So what is the relation between
thought an language? One hypothesis is that there is a “language of thought”
that represents in much the same way as language, that is, it is a symbolic
system realized in the brains of relevant organisms. It has, however, been
argued that not all thought is linguistic: for
example, perhaps a craftsman thinks with his hands. Sometimes thoughts
are accompanied by mental imagery: thinking of someone often seems to involve
calling a picture of them to mind. Perhaps such images are more important for
thinking than the linguistic expression of thoughts. There are also other
questions relating to the ways in which language can constrain what we can
think: if we can only think with concepts we have in language, then different
linguistic communities will have different capacities for thought.
Questions for Discussion
Do thoughts represent states of affairs, and if
so how? What is the difference between believing that something will happen,
and hoping that it will? What is the role of mental imagery in thinking? What
is the role of language in thinking? Is the language of thought (“Mentalese”) hypothesis plausible? If so, does it support
the idea of Artificial Intelligence? Is it essential for AI?
Week Seven
Action, Intention and Will
The ability to act is important part of what
it is to be an intelligent being: it is purposive behaviour that we attempt to explain using metal
concepts. But what makes an event an action?
There is a difference between a person’s actions, and things that happen to
them, but we need to characterize this difference precisely. Next we need to
distinguish things that people do, from things that merely happen as a result
of what they do. We also want to distinguish intentional and voluntary actions
from unintentional and involuntary actions. We also need to relate actions to
desires, beliefs and volitions.
Questions for Discussion
When can an event be said to be an action? What makes an action intentional, and what makes an action voluntary? Are reasons for action different from the causes of actions? Some modern computer systems, called autonomous agent systems, are based on the Belief-Desire-Intention (BDI) model. What do we want to say about the actions performed by such systems?
1. Lowe, Chapter 9.
2. Mike Wooldridge’s Agents Slides http://www.csc.liv.ac.uk/~mjw/pubs/imas/distrib/pdf-index.htm especially lectures 2 and 4.
3. Actions, Reasons, and Causes Donald Davidson The Journal of Philosophy, Vol. 60, No. 23, American Philosophical Association, Eastern Division, Sixtieth Annual Meeting. (Nov. 7, 1963), pp. 685-700. http://www.jstor.org/view/0022362x/di972820/97p0027b/0
4. The on line sources: try “action” “practical reason” and “free will”.
Week Eight
Consciousness
Consciousness is at
once familiar and puzzling. We are constantly aware of “ourselves” as things
with a past, present and future, and this conception of a persistent self
unifies our experiences into a coherent pattern and has an enormous influence
of what we think and do. We are also inclined to think of ourselves as in some
way separate from the world. Moreover we see (some) others as being similarly
persistent things. Questions about consciousness include:
·
simple
description: what are its features (for ourselves and for other conscious
beings)?
·
explanation:
how can consciousness (come to) exist?
·
function:
what is the role of consciousness features (for ourselves and for other
conscious beings)?
There are a number of theories of
consciousness, both dualist and material, but no real consensus on these
issues.
Questions for Discussion
Are the problems
associated with consciousness different for first person as opposed to third person
attributions of consciousness? Can any of the theories of consciousness
satisfactorily account for both first and third person phenomena? Can any
account for either satisfactorily? Is there a satisfactory solution to the
problem of other minds? How do the problems of consciousness and other minds
relate to the notion of intelligent machines?
1. Lowe doesn’t say
very much about consciousness explicitly, but there is an excellent and
thorough article in the Stanford on-line Encyclopaedia: http://plato.stanford.edu/entries/consciousness/
2. An article by Alex
Byrne. http://www.bostonreview.net/BR31.3/byrne.html
3. There is also an interesting article in the Routledge on-line Encylopaedia: http://www.rep.routledge.com/article/W011?ssid=53827009&n=1#
4. The Stanford entry on Other Minds http://plato.stanford.edu/entries/other-minds/#3.2
Week Nine
The Turing Test
The Turing Test was proposed by Alan Turing to
give a procedural meaning to the question “Can Machines Think?” The basic idea
is that if a machine and a human being answer questions from an interrogator
and the interrogator cannot tell which is the machine and which is the human,
the machine will pass the test.
The sort of questions and answers envisaged by
Turing are
Q: Please write me a sonnet on the subject of the
A: Count
me out on this one. I never could write poetry.
Q: Add
34957 to 70764
A: (Pause
about 30 seconds and then give as answer) 105621.
Q: Do you
play chess?
A: Yes.
Q: I have K at my K1, and no other pieces. You have only K at K6 and R at R1.
It is your move. What do you play?
A: (After
a pause of 15 seconds) R-R8 mate.
There have
been some attempts to build programs to pass the test. Among the earliest and
best known is the Eliza program of Joseph Weizenbaum,
intended to mimic an emphatic psychologist (although Weizenbaum
firmly denied that Eliza was in any way thinking). This program made use of a
number of much imitated techniques. Another program PARRY mimicked a paranoid.
There is still a competition for machines: a recent winner is Joan.
Questions for Discussion
Is the Turing test
fair? If it unfair, is it unfair to the human or the machine? Current programs
seem little better than Eliza: why was initial progress towards satisfying the
test so good, and subsequent progress so slow? What would passing the test
prove? Machines have developed a long way since Turing’s time: can the test be
updated? Would this provide convincing evidence of a thinking machine? Is there
an alternative to the Turing test which would establish that a machine was
thinking?
1. A.M. Turing, Computing Machinery and Intelligence, Mind, 1950, vol. 59, no.236, pp. 433 – 460. Text and a commentary can be found at http://www.abelard.org/turpap/turpap.htm
2. Joseph Weizenbaum, ELIZA--A Computer Program For the Study of Natural Language Communication Between Man and Machine, Communications of the ACM Volume 9, Number 1 (January 1966). http://i5.nyu.edu/~mm64/x52.9265/january1966.html
3.
Dialogues with Eliza, Parry and
Racter
http://www.stanford.edu/group/SHR/4-2/text/dialogues.html
4. Joan http://www.guardian.co.uk/comment/story/0,,1879142,00.html
5. Lowe Chapter 8, especially 209ff
Week Ten
Searle and the Chinese Room
Searle in his 1980 paper Minds, Brains, and Programs, sets out to prove that Artificial Intelligence is not possible. His strategy is to se t up a situation in which all the aspirations of AI are satisfied, but in which it is clear that no intelligence is involved. Briefly stated, is scenario is a man inside a room who is given written questions in Chinese. He has a manual which leads him to given written answers in Chinese which are considered appropriate by the questioners. But neither he, nor the “room” understands Chinese: everything is mechanical, no intelligence is required to produce the answers. The article produced a great deal of controversy, and a number of leading workers in AI gave their replies. It remains to this day the best known argument against the possibility of AI.
Questions for Discussion
Does Searle’s example give a fair picture of what people in AI are trying to produce? Does it apply to today’s systems as well as those of 1980? Can we think of systems (current or future) to which his argument would not apply? Are any of the replies to Searle convincing, or does he meet all the objections? If not, should we abandon AI?
1. Searle’s original article "Minds, Brains, and Programs," by John R. Searle, from The Behavioral and Brain Sciences, vol. 3 can be found at http://members.aol.com/NeoNoetics/MindsBrainsPrograms.html
2. The peer response to Searle are also in volume 3 of The Behavioral and Brain Sciences. These are not on line, but the volume is in the Sidney Jones Library at QP351.B2 . I have distributed a photocopy.
3. Internet Encyclopaedia of Philosophy http://www.iep.utm.edu/c/chineser.htm
4. Lowe ch8, especially 214ff
Weeks Eleven and Twelve
The Intentional Stance: Can
Machines Think?
Daniel Dennett argues
that when explaining or predicting behaviour we can adopt one three stances: the design stance, the physical stance and the intentional
stance. Which is best to adopt depends on which works best. For a simple
program the design stance is good, but for a malfunctioning system we need the
physical stance (“it won’t work if it is not switched on). But for complex
systems (e.g. chess playing systems) the intentional stance is the most useful.
We don’t worry about “real” beliefs and desires, we simply ascribe them because they are useful. The intentional stance
requires us to presume rationality. The intentional stance is widely used in
common sense reasoning, but scientific can move us from the intentional stance
with the design stance.
"Here is how it works: first you decide to
treat the object whose behavior is to be predicted as a rational agent; then
you figure out what beliefs that agent ought to have, given its place in the
world and its purpose. Then you figure out what desires it ought to have, on
the same considerations, and finally you predict that this rational agent will
act to further its goals in the light of its beliefs. A little practical
reasoning from the chosen set of beliefs and desires will in most instances
yield a decision about what the agent ought to do; that is what you predict the
agent will do." (Daniel Dennett, The Intentional Stance, p. 17)
Questions for Discussion
Is Dennett’s
description of the three stances convincing? Do we use them? Are there
implications for philosophy of mind: is any particular theory of mind in tune
with the intentional stance? Could we apply the intentional stance to
ourselves? How well does the intentional stance explain human behaviour? Are there other stances that we can use? How
does Dennett’s idea relateto the question of whether
machines can think? Can they? Do they?
1. Chapter 1 of Brainstorms (handout).
2. A Dialogue on the Web http://www.consciousentities.com/dennett.htm
3. Wikipedia http://en.wikipedia.org/wiki/Intentional_stance
1. Introduction and
overview: Minds and Bodies, People and Machines
2. Scepticism and the
Argument from Illusion
3. Dualism
4. Behaviorism,
Functionalism and Identity Theories
5. Perception
6. Thought and Language
7. Consciousness
8. Action, intention
and will
9. Machine Intelligence
and the Turing Test
10. Searle and The
Chinese Room argument
11
and 12. Dennet
and the Intentional Stance: Can Machines Think?