i) Introduction
ii) In
Reference to Reference
iii) Mental
Content
This
is a simple introduction to the philosopher John Searle's main
argument against artificial intelligence (AI). This means that it
doesn't come down either for or against that argument.
The
main body of the Searle's argument is how he distinguishes syntax
from syntax. Thus the well-known Chinese Room scenario is simply
Searle's means of expressing what he sees as the vital distinction to
be made between syntax and semantics when it comes to debates about
computers and AI generally.
In
Reference to Reference
One
way in which John
Searle
puts his case is by reference to reference.
That
position is summed up simply when Searle (in his 'Minds,
Brains, and Programs'
of 1980) writes:
“Whereas
the English subsystem knows that 'hamburgers' refers to hamburgers,
the Chinese subsystem knows only that 'squiggle squiggle' is followed
by 'squoggle squoggle'.”
So
whereas what Searle calls the “English subsystem” involves a
complex reference-relation which involved entities in the world,
mental states, knowledge of meanings, intentionality, consciousness,
memory and other such things; the Chinese subsystem is only following
rules. (The computer will have a memory; though a memory with none of
the features talked about here.) That is, when the input 'squiggle
squiggle' is fed in, the Chinese subsystem delivers (or computes) the
answer 'squoggle squoggle'. This is really a simple case of the
computer (or Chinese subsystem) following x
with y.
And that's simply the result of following a rule (or an algorithm).
Again, knowledge of meanings, intentionality, consciousness, etc.
aren't required in this simple case of following a rule/algorithm.
When
its puts like this it seems that the computer/Chinese subsystem is a
system which is of the same type as a thermometer; except that the
system is more complex and it involves inscriptions and
rules/algorithms. (Then again, a thermometer can be given a
computational or mathematical explanation/description too!)
Margaret
A. Boden
(in her paper 'Escaping
from the Chinese room'
- 1986) offers a little more detail on what she calls the “causal
semantics”
of reference (whether beliefs or individual words/terms). She
writes:
“In
a causal semantics, the meaning of a symbol (whether simple or
complex) is to be sought by reference to its causal links with other
phenomena.”
Above
a beyond that, Boden does ask a couple of questions about this aspect
of causal semantics. She
writes:
“The
central questions are 'What causes the symbol to be built and/or
activated?' and 'What happens as a result of it?' The answers will
sometimes mention external objects and events to an observer,
sometimes they will not.”
The
first point to make here is that it's obvious that a computer (or
even a man in a Chinese room) has no causal links to the things it's
answering questions about. Of course it can be said that there are
indirect causal links. Indeed some theories of causal reference (or
semantics) have tackled these indirect (or circuitous) causal links.
For
example, the data that's fed into a computer has causal links to
external objects care-of the computer programmer. It's the programmer
himself
who has causal links (expressed in the data which is fed into the
computer) to external objects or events. (This parallels Searle's “as
if” intentionality.)
The
final clause about sometimes not mentioning external objects is
possibly a reference to some of the problems found with causal
semantics. Such problems include that of a reference-relation to a
non-existent entity or to an event which occurred in the past. There
are various solutions to these problems. However, I don't think they
are relevant to the issue under discussion because some of these
causal accounts of reference to non-existent entities still supply us
with causal explanations.
Mental
Content
Searle
also argues for his position in terms of mental content; though
reference itself will involve mental content.
The
usual way that other people have put Searle's position is by saying
it's a case of syntax
vs. semantics.
Though Searle expresses pretty much the same thing here in terms of
form vs.
mental content.
This is how Searle himself
puts
it:
“...
the program is purely formal, but the intentional states are not in
that way formal. They are defined in terms of their content, not
their form.”
That's
the technical terms “form” and “content” out of the way.
What, exactly, does Searle mean by them? He continues:
“The
belief that it is raining, for example, is not defined as a certain
formal shape. But as a certain mental content with conditions of
satisfaction, a direction of fit and the like. Indeed the belief as
such hasn't even got a formal shape in this syntactic sense, since
one and the same belief can be given an indefinite number of
different syntactic expressions in different linguistic systems.”
Here
we find two technical terms/phrases which were (as far as I know)
coined by Searle himself. In fact they're more or less two ways of
saying the same thing: viz., “conditions
of satisfaction”
and “direction
of fit”.
Conditions
of satisfaction seems
to be a phrase which belongs to a theory of reference in that in
order for a word or a belief (in Searle's example) to have a
reference to something outside the head (or beyond the page), it must
have conditions
of satisfaction.
There must be something in the world (a condition) which satisfies
the belief (or word). In Searle's example, the belief that it is
raining has the condition of satisfaction if and only if it is indeed
raining. (This appears to be similar to a Tarskian
T
sentence
in which the sentence is simply disquoted to provide its truth
conditions.)
As
for “direction of fit”, this seems to be a theory within (mental)
intentionality in that a belief (or a word) must have directedness
(or an “intentional relation” to) something outside the head and
in the world. However, the phrase “direction of fit” seems
equally suitable to a theory of reference in that a
reference-relation itself will require a direction of fit.
It
certainly seems true that a belief itself couldn't possibly have a
“formal shape”; at least not until it's given a formal shape when
expressed in words or symbols. As mental content only, it has no
formal shape or syntax. Indeed it can be said that no example of
mental content could have a formal shape. (Except in the indirect
sense that beliefs refer to things which have shapes or that mental
images can be said to have shapes or at least be about – or
representations of – shapes.)
I've
just mentioned that non-formal beliefs or mental content generally
can indeed be given formal shape when expressed in words or symbols.
Searle himself
says that
“the
same belief can be given an indefinite number of different syntactic
expressions in different linguistic systems”.
That
means that belief P
can become, for example, S1,
S2,
S3...
Sn
when it's expressed. S1,
S2,
S3...
Sn
are the syntactic expressions of P.
In all these cases, P
remains the same; whereas S
will differ syntactically. In other words, the belief that it
is raining
can become “It is raining”, Il
pleut,
「雨が降っれます」or
be given an artificial expression in some kind of computer code. The
belief it
is raining
can even be expressed in Morse code; providing we have a translation
manual and we know the translation.
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