A Taster of Philosophical Issues
Arising from an AI Project
Lecture for Philosophy of Cognitive Science
2011/2012 Semester 2
John Barnden (Prof of AI)
School of Computer Science
University of Birmingham, UK
Plan of Lecture
• Beginning (well defined)
• Middle (variable)
• End (poorly defined)
because I want questions and discussion
THEME:
I’ll give you a taster of some of the philosophical issues that have arisen in my
research or are related to it.
Some Questions to You (QTYs)
• At what address did Sherlock Holmes live?
• Is London the city in which the SH stories are set?
• Has SH died yet?
• How many warts did he have?
• How many legs does a unicorn have?
• What is a number?
• Where do all the numbers, sets, computer programs, ... live?
• What does/might “Everyone is a moon” mean?
• What does/might “The Government’s plan for the NHS is really fantastic” mean?
• Perhaps there’s something wrong with some of these questions? (QTY4L8R)
... Beginning ...
• My main research interest:
– AI methods for understanding figurative language
– and the interdisciplinary (incl. philosophical, psychological, linguistic)
ramifications
– and the practical applications
Figurative language = metaphor, irony, hyperbole (exaggeration), etc.
• Subsidiary interests:
– consciousness, emotion, ...
– creativity (of any sort, incl. artistic and scientific)
(there’s a growing Computational Creativity subarea of AI)
– nature of representation
Still Beginning
• Some of the importance of "philosophical" issues to CS and AI:
They’re often about deep conceptual matters that can affect the whole
enterprise of developing a computational approach to some problem area.
Proper philosophical consideration can help you avoid getting into overly
abstract, unrealistic approaches.
End of the Beginning:
Issue Morsels
• FICTIONALISM
everyone entertains lunatic fantasies all the time?
numbers, programs etc. ain't what you thought they were
in fact they aren't anything?
• METAPHOR IN THOUGHT
mind as metaphorical mush
• BOUNDARIES OF MEANING
meaning as a holistic gas
hidden meanings rule OK
Practical Importance of Fig Lang
Common in language, so ultimately needs to be dealt with in AI language
systems of many different sorts
Becoming important in Sentiment Analysis systems, for extracting
evaluative opinions and emotions from product reviews, customer
complaints, etc.
Becoming important in the security area, because metaphor etc. can be
culture-specific
Metaphor is important in psychotherapy
Conversation about practical matters (e.g. travel) involves metaphor, etc.
A Fictionalist Approach to Metaphor
in the ATT-Meta theoretical approach to metaphor understanding, with
accompanying implemented system for handling the reasoning involved.
• Uses a fictionalist or pretence-based approach, whereby the typically absurd
literal meaning of the metaphor is pretended to be true, and consequences
about the real world extracted by various means.
• But, as with many other approaches, if a metaphorical word or phrase is
conventional/familiar enough then its meaning may be directly accessible
from it.
• Possible examples: milestone, attack, dead, back of X’s mind
• The most interesting cases are the remainder. I claim many/most of these
are handled by pretence.
Examples of Metaphor
“John’s exam marking overflowed into the weekend”
“The idea was buried in the far reaches of Katy’s mind”
“I don’t think strings are attached. If there are any they’re made of nylon” [QTY]
“The managers were getting cricks in their necks from talking to [lots of different
people]”
“I nurtured those doubts as if they were tiny, sickly kittens.” [Nick Hornby]
“Everyone is a moon, and has a dark side which he never shows to anybody.” [Mark
Twain] (QTY: notice something wrong with that?)
“I’m going to give you a taster of philosophical issues. ..... Issue Morsels”
Some Terminology
• A metaphor has a “source side” and a “target side”.
In “John’s exam marking overflowed into the weekend”,
– the target side is to do with John’s marking in itself
– the source side is to do with physical liquids, their movements, physical
containers, etc.
• I talk of source-side and target-side subject matter, situations, scenarios, ...
• The two sides are conceptual, not primarily parts of the wording.
The Fictionalist Process
“The idea was buried in the outback of Katy’s mind”
• The understander (as well as the speaker) momentarily pretends that Katy’s
mind is literally a physical terrain that has an outback and that the idea is
literally physically buried in the outback.
Physical burying, especially in relatively inaccessible locations such as an
outback, implies (by default):
– a high degree of current lack of physical manipulability and physical
hiddenness
– and a high degree of difficulty for attempts to physically manipulate it.
• So the idea in question is inferred to be (to a high degree) physically hidden
to, currently physically unmanipulable by, and difficult to physically
manipulate by Katy’s conscious self.
J = the idea
Reality (incl.
target-side)
J is buried in ...
J is a phys object
K’s mind is a phys terrain
inference
K is not aware of J
J phys’ly hidden to K’s c. self
J not phys’ly manipulable by K’s c. self
J would only be
manipulable with difficulty
by K’s c. self
K cannot mentally use J
K would find it difficult
to mentally use J
pull-out
Examples of Known Mappings
• For the metaphorical view of IDEAS AS PHYSICAL
OBJECTS, we might have:
– X mentally using an idea 
X’s conscious self physically manipulating the physical
object that the idea is pretended to be.
– X being [consciously] aware of an idea 
X’s conscious self seeing the physical object that the idea
is pretended to be.
Notes on Pretence
• The word “pretence” has a number of different meanings, and people have
different intuitions about what it covers.
The relevant notion in the ATT-Meta approach does not imply any sort of
deception or insincerity.
Rather it is honest pretence, usually but not necessarily as part of a
communication with someone else. Some cases:
– Fiction in general (NB: pretending that as opposed to pretending to)
– Drama
– Children’s pretend play
– Fancy-dress balls (adults’ pretend play!)
– Counterfactual statements: “If I were the head of the Football Association I’d set
up a new world governing body for football.”
Fiction[alism]: Other Issues
• In narrative fiction: what sense can we make of fictional entities?
– where does/did Sherlock Holmes live?
– how many warts does/did he have?
– does he exist even when no-one in the whole wide world is reading or
thinking about him?
– What about if also all books etc. about him have been destroyed?
– if someone else wrote an SH story/film—would it be about the same
entity?
Fictionalism: Other, contd
• Fictionalism about what we normally think of as real: e.g. about
numbers (QTYs) :
– what is a number?
– do they exist?
– where are they?
– would they exist if there were no people?
• Arithmetic is like a Sherlock Holmes story?
The connections are deductively certain, as opposed to SH fiction,
so it's easier to agree on the rules.
Fictionalism: Arithmetic, contd
• But there is dispute about the tenets of the underlying set theory
e.g. whether a set can belong to itself; questions about the
nature of infinite sets.
• Sets themselves are fictional?
•
What about computer programs? (QTY)
Metaphor in Thought
• A common modern view: metaphor is not fundamentally a matter
of communication / external expression, but of the way we think
about many aspects of life (where the thinking is not itself a
matter of internal English or whatever).
• Metaphor is in many different forms of communication,
expression and other activity:
– Gesture
– Diagrams (cf. arrows, blobs, etc. in my diagram above: QTY4L8R)
– Pictorial representation
– Dance
– Music
– Sport, Games
But what does M4-in-T amount to??
• A weak analogy-based view:
–
we can in principle think about, say, love without metaphor,
– but have analogies in our minds with separate knowledge structures about
journeys, businesses, etc.
2 variants:
– the knowledge structures have separate origin, but we established an
analogy (in our lifetimes or during species development)
– the structure of (some of) our knowledge about love comes from
knowledge about journeys, etc.
•
A very strong view:
– our knowledge structures about love actually intrinsically involve our
knowledge structures about journeys, etc.
Metaphor in Thought, contd
• Some possibly relevant psychological experiments show there’s
some sort of embodiment of metaphor, even metaphor that is
highly “conventional.”
E.g., bodily movement can affect our inferences about time.
– We talk metaphorically about time as if it were a spatial dimension.
On one metaphorical view, we’re moving along a time line.
On another, future times and events are moving towards us.
– They give exactly opposite meanings for e.g. “Let’s move the meeting
forwards.”
– Engaging in or even imagining forwards movement has been shown to bias
people towards interpreting that phrase to mean: make it later.
• QTY4L8R: what does this show about metaphor in thought, if anything?
That’s as far as I got in the lecture
The Restrained-Parallelism Tendency
in Metaphor according to ATT-Meta
There is less parallelism needed in metaphor than often
implied/assumed
“The idea was buried in the outback of Katy’s mind.”
•
My claim: “buried” and “outback” are merely
mental tools towards the target-side meaning ...
via existing mappings such as
physical operation  mental usage.
There is no need to, and it could be difficult to,
discover mappings for the map-transcending notions introduced by
“buried” and “outback”.
The familiar, existing parallelism (analogy), e.g. between mental
matters and physical matters, need not (and often cannot) be extended.
Restrained Parallelism, contd.
– “He was spinning his wheels”:
his wheels don’t need a parallel.
– “I don’t think strings are attached. If there are any they’re made of nylon”:
made-of-nylon, or nylon and made-of separately, don’t need parallels.
– “The managers were getting cricks in their necks from talking to [lots of different
people]”:
cricks and their necks don’t (normally) need parallels.
(Grammatical) Boundaries of Meaning
• “Everyone is a moon, and has a dark side which he never shows to
anybody.” [Mark Twain]
A possible variant (QTY) :
“Everyone is a moon. Everyone has a dark side which he never shows to
anybody.”
• The clause/sentence “Everyone is a moon” does not need to be given its
own target-side meaning.
Rather, it conspires with the other clause/sentence to convey an overall
fictional/pretence scenario.
Indeed, the moon clause/sentence really just consolidates the info from the
other segment. [Or would do if it were astronomically accurate!]
(Grammatical) Boundaries, contd.
• This and many other examples suggest that:
Meaning from discourse should not be thought to be tied to (bits
of) sentences in particular: rather it can arise in a much more
holistic way from arbitrary stretches of discourse, involving various
sentences and bits of sentences.
Viewing sentences as the central meaning-bearers is just an
artefact of traditions in language study over the centuries.
• Speech units =/= sentences, particularly.
And meaning in speech is partly carried by intonation, gesture, etc.
which don’t necessarily respect sentence boundaries.
Boundaries of Meaning:
Different Types of It
• A highly contentious distinction:
“What is [directly] said” [WiS] versus
“What is implicated” [implicatures]
• Some people view metaphorical meanings as implicatures from
WiS, at least when not conventional.
• More standard example:
Saying “You’re squashing my arm” to mean Get the hell over to
the other side of the bed.
• Very difficult in general to draw a clear distinction.
WiS vs Implicatures: Irony Case
“The Government’s plan for the NHS is really fantastic.”
• WiS = the literal meaning of that.
• Implicatures:
Ironic content:
The plan is bad.
Ironic attitude:
[e.g.] It’s pretty idiotic to think it’s a good plan.
Syntactically Embedded Irony
S: “If Alice is such a genius we’ll be sure to lose in the quiz.”
NB: Only the antecedent is ironic.
• Appropriate in various types of context:
– People have already been talking ironically about stupid Alice.
[S continues existing negativity and irony.]
– People have been talking non-ironically about stupid Alice.
[S continues existing negativity but introduces irony.]
– People have been sincerely claiming Alice is clever but the speaker of S
isn’t convinced.
[S introduces negativity and irony.]
Embedded Irony, contd.
• Raises issues for the WiS/Implicature distinction, and for the role of different
implicatures.
• Sentence S’s consequent clause is asserted to hold if the ironic content of the
antecedent (Alice is stupid) holds: the literal content and the attitude
implicature are both irrelevant.
• Need a way of explaining what the fate is of different implicatures of different
sorts of statement in different sorts of embedding, and of working out fairly
clearly what some of the specific implicatures are.
• And is the natural interpretation of S itself a WiS or an implicature?
– If the former, a WiS can depend on an implicature, upsetting standard theories of
WiS.
– If the latter, the WiS is strangely irrelevant: do we work it out at all?
“Conclusion”
(= Start of Next 1000 Years of Philosophy)
• FICTIONALISM
Metaphor: everyone entertains lunatic fantasies (fictions)?
(More) Fictionalism: numbers, programs etc. ain't what you thought they
were. In fact they aren't anything?
• METAPHOR IN THOUGHT
mind as metaphorical mush: some of our thought may be intrinsically
metaphorical (and that’s a good thing – I like mush!).
• BOUNDARIES OF MEANING
meaning as a holistic gas/mush, not linked to fixed grammatical boundaries.
hidden meanings rule OK: implicatures are often crucial.
A Few References
•
Barnden, J.A. (2007). Metaphor, semantic preferences and context-sensitivity. In K. Ahmad,
C. Brewster and M. Stevenson (Eds), Words and Intelligence II: Essays in Honor of Yorick
Wilks, pp.39-62. Berlin: Springer.
•
Barnden, J.A. (2008). Metaphor and artificial intelligence: Why they matter to each other. In
R.W. Gibbs, Jr. (Ed.), The Cambridge Handbook of Metaphor and Thought, pp.311-338.
Cambridge, U.K.: Cambridge University Press.
•
Many other chapters in that Handbook.
•
Casasanto, D. & Boroditsky, L. (2007). Time in the mind: Using space to think about time.
Cognition, 106, pp.579-593.
•
Currie, G.~(2006). Why irony is pretence. In S. Nichols (Ed.), The Architecture of the
Imagination, pp.111-133. Oxford: OUP.
•
Fogelin, R.J. (2011). Figuratively speaking. Revised ed. New York, Oxford: Oxford University
Press. (The main library has the 1988 edition, which is also fine.)
•
John, E. & Lopes, D.M. (2004). Philosophy of Literature: Contemporary and Classic
Readings. Blackwell.
•
•
Despite the title, many of the chapters are significant beyond literature.
((I can provide more references on specific topics.))
Do the cat-flaps of time allow the
aardvarks of questioning to snort
up the maggots of incoherence?
EXTRA SLIDES
Honest Pretence
• Any sort of imagining (conscious or not) of a situation you think is unreal,
and is presented in that spirit to yourself or others, is honest pretendingthat.
• This isn’t to say that it’s immediately obvious to another person that you’re
engaging in pretence, or that there are clear signals that pretence is going on.
The Fictionalist Process: a detail
• I claim that mind-as-physical-region metaphors involve the ancillary
assumption that
the person’s conscious self is pretended to be
a person in a central part of the region.
The ATT-Meta Approach, contd
• So what??
We now need to have some way of “pulling out” some version of some
information in the pretended situation
to become information about the target situation (Katy’s actual state of mind).
• What I’m aiming for in the Katy example is that by pull-outs the understander
derives the propositions that (to a high degree)
Katy is not aware of the idea,
cannot currently mentally use the idea, and
would find it difficult to mentally use it.
The ATT-Meta Approach, contd
• For purposes of pull-out in general, there are three logical possibilities:
• Some information may be able to be copied over as-is (no transformation)
• We have known transformations of some types of information
• We work out new transformations of some information from scratch.
• All three are veteran actors on the stage of metaphor theory
(pretence-based or not).
• New-transformation has been postponed in the ATT-Meta project: can be
important, but only rarely so in practice (even in literary metaphor – cf.
[Lakoff & Turner & 1989])
• No-transformation and known-transformation are used in ATT-Meta.
Known-transformation: roughly following the idea of “mappings” in
Conceptual Metaphor theory [Lakoff & Johnson; Grady variant] and in
research on analogy.
The ATT-Meta Approach, contd
• No-transformation case: done by View-Neutral Mapping Adjuncts (VNMAs).
They lead to copying of certain types of commonly-occurring information.
• Example:
IF
pretend action P
corresponds to target-situation action Q
AND IF pretend agent X
corresponds to target-situation agent Y,
THEN ability of X to do P corresponds to ability of Y to do Q
(by default)
• They are parasitic on existing postulated pretence/target correspondences
(mappings).
But they are independent of where those correspondences come from, and
notably from what specific metaphorical views (such as IDEAS AS PHYSICAL
OBJECTS) are in operation.
• VNMAs provide great economy: e.g. No need to have an ability version of the
view-specific physical-manipulation/mental-usage mapping, or ability version
of other mappings.
Info Handled by some VNMAs
• ability, ease, causation, enablement, etc.
• degrees (intensities)
• modalities (incl. “if ... would”)
• uncertainty
• event shape, temporal relationships
• sets, qualitative set sizes
• emotional and mental states, value judgments
Other No-Transformation Cases
• Any type of info could, in the right specific circumstances, correspond
without transformation.
– E.g., one might metaphorically cast a person as a horse because of the shape
of their nose and their speed of running.
• The point is that only certain types of information can be assumed to
correspond when there’s no specific counter-evidence.
• A person/horse metaphor would not allow one to assume that the person
eats raw oats, etc., just because there’s no evidence that the person does
not eat those things.
– One might of course wonder whether the person eats those things.
– And in the right context, part of the point could be that the person does eat
those things.
• So:
– VNMA-style info: can copy over
– Other Info:
unless there’s a reason against
cannot copy over unless there’s a specific reason for
Mappings as working on Pretence
Rather than Domains of Knowledge
• In other approaches, mappings are thought to be between a source
domain and a target domain (or other similar constructs), where domains
are subdivisions of our knowledge of the world.
This rests on notions of domain (etc.) that I don’t believe.
• I cast mappings as just relating two different things (no matter what
“domains” these things might involve), where one thing is assumed to be
in a pretended scenario and the other in a target-side scenario.
[related to Walton’s “principles of generation”]
• I don’t assume any precise delineations of subject-matter.
• The subject-matter in the pretence is typically from the source side of the
metaphor, but can include real (non-pretend) information, and any subject
matter that is relevantly connected to the source-side subject matter.
Pretence Alongside another Unreality
J is a phys object
K’s mind is a phys terrain
J is buried in ...
Non-real
target-side
K is not aware of J
J phys’ly hidden to K’s c. self
J not phys’ly manipulable by K’s c. self
J would only be
manipulable with difficulty
by K’s c. self
K cannot mentally use J
K would find it difficult
to mentally use J
Multiple Pretences
• Consider a play within a play, or a story within a story.
This involves nested fictions, i.e. nested pretences.
Nesting of pretences/fictions in the language area also has been discussed in
heterogeneous cases, as when there is an ironical statement by a character in a
fictional work [Currie 2006].
• But also useful for serial compounding (chaining) of metaphor:
X viewed as Y and Y viewed as Z
• E.g.: “This worry was a corrosive chemical that was nibbling at her self-esteem.”
[closely adapted from an example in a Sylvia Plath diary]
• The worry (X) is viewed as a chemical (Y);
the chemical (Y) is viewed as an animal (Z).
the second view is typically expressed as acids, etc. “eating [into]” things.
[Also, her self-esteem is viewed as a nibblable physical object.]
The worry-chemical-ANIMAL is
nibbling at her self-esteem-object
The worry-chemical-ANIMAL is slowly
eating her self-esteem-object
The worry-CHEMICAL
is slowly physicallydamaging her selfesteem-object
The WORRY is
slowly affecting her
self-esteem
negatively
Multiple Pretences, contd
• Multiple (but non-nested) pretences also useful for
Parallel compounding of metaphor:
X
is viewed as
both Y and Z
where Y is not itself (on this occasion) viewed as Z,
and
Y and Z are difficult to combine within one pretence.
• “Marriage is both a business and a journey”.
• There are sometimes complex combinations of parallel and serial
compounding.
BUSINESS info
MARRIAGE info
JOURNEY info
Restrained Parallelism contd
• Adapted from a novel [Nick Hornby, High Fidelity, 1995]:
“I tried not to run down Phil too much. But it became unavoidable, when
Jackie expressed doubts about him. I nurtured those doubts as if they were
tiny, sickly kittens. Eventually they became disturbing, long-lasting grievances.
These cats had their own cat-flaps. This allowed them to wander in and out of
our conversation at will.”
• The cat-flaps and at-willness don’t themselves need target parallels. They
just emphasize, via the pretence scenario, the non-deliberateness (on the
part of the conversants) with which the grievances occurred in the
conversations.
• Even the cat-ness in the pretence scenario has no target-side parallel. It just
provides a conceptual framework for describing a process in which doubts
become strong grievances.
Grain-Size of Metaphorical Interpretation
• “These cats had their own cat-flaps.”
• This sentence does not (need to) have its own target-side
meaning.
• The appropriate level for metaphorical interpretation is
sometimes a multi-sentence chunk of discourse (or a chunk
consisting of multiple metaphorical clauses). I.e.:
– Individual metaphorical units within the chunk are not all given separate
interpretations. Rather, the whole chunk describes a pretence scenario,
and it’s from this that the target-side info is derived in a somewhat
holistic way.
No necessary sentence-by-sentence or clause-by-clause parallelism.
Shifting into Reverse: Metaphorization
• Literal elements of a discourse may best be translated into terms of the source
side to engage with the pretence scenario: metaphorization of the literal —
— reverse of normal process assumed in metaphor understanding!
• It is intuitively natural to build in one's mind a scenario of the sickly kittens
becoming healthy kittens or adult cats.
• But where is this biological recovery and growth implied? Answer: in the literal
sentence “Eventually they became disturbing, long-lasting grievances.”
• Metaphorization of the info from this sentence is desirable, in order to enrich
and be integrated with the pretence scenario.
• And if we claimed that the integration should instead happen on the target
side, then there’d be more pressure to try to convert all sentences including
“These cats had their own cat-flaps” into target terms — with great difficulty.
Metaphorization, contd.
• Actually, Hornby’s original wording was not
“Eventually they became disturbing, long-lasting grievances” but
“Eventually they became sturdy, healthy grievances”.
• But still, desirable to convert grievances into cats
and convert the abstract became into biological growth and recovery.
• Don’t want just to get target-side info from the sentence by itself.
Conclusions, 1
• Restrained parallelism:
Metaphorical wording often plays the important role of guiding inference
within the pretence whose conclusions are mapped, rather than
describing pretence elements that should, or even could, be mapped.
• So the interpretation job is Simpler than you may have thought (less
mapping-construction)
but also More Quirky than you may have thought (the wording has
less to do with the target side, and is more unconstrained).
Conclusions, 2
• A special corollary, with Yet More Quirk :
The grain-size of truth attribution to language (even when literal?) is not
the sentence in general.
Sentences (etc.) collaborate with each other to describe pretence
scenarios without necessarily having their own individual target-side
meanings. [cf/cp. Donald Davidson]
Sentence-by-sentence truth is just a convenient heuristic fiction [sic!]
that works well enough much of the time.
• Quirk Alert:
Depending on context, it can make sense to
metaphorize literally-presented information in discourse.