Searle, Harnad and understanding Chinese symbols

[Richard Yee]

	== More Chinese-Room Talk ==

	I find myself in the apparently paradoxical position of
agreeing with virtually all of Searle's assertions in the "Chinese
Room" argument, and yet disagreeing with his conclusion.  Likewise,
I agree with Harnad that an intelligent (cognitive?) processing
system's input symbols must be "grounded" in subsymbolic
representations (in what I call internal semantic or interpretive
representations), yet I disagree with his defense of Searle's
counter to the "Systems-Reply".  What follows is a rather long
message which, I claim, demonstrates that the conclusion that
Chinese is NOT being understood inside the Chinese Room has no
basis.  This rescues us from having to conclude that either
understanding is uncomputable or the Church-Turing Thesis is wrong.
The reason that the possibility remains open as to whether the
inputs (Chinese characters) are being understood, is basically
related to the Systems Reply with one important caveat: there is
also no basis to the claim that the Chinese characters ARE being
understood, and to the extent that the Systems Reply claims this I
would not defend it.  The question is whether the Chinese language
performance (CLP) being observed externally arises from an
understanding of Chinese (UC) or from some other process (not UC);
the Chinese Room scenario does not present enough information to
decide the question either way.

	Harnad describes the crux of Searle's argument against the
Systems Reply as being that the person in the room is "in fact
performing ALL the FUNCTIONS of the system" (possibly through having
learned the rules), and yet clearly the person does not understand
Chinese.  Both of these statements are true, but this does not
justify the conclusion that the process of understanding Chinese is
not occurring.  The determination of outputs is under the complete
control of the rules, not the person.  The person has no free will
on this point (as he does in answering English inputs).  All and
only those transformations licensed by the rules will determine what
the Chinese outputs will be.  Thus, although it is clearly true
that, e.g., the input symbols (Chinese characters), "HAN-BAO-BAO",
have form but absolutely no content for the person, this in no way
implies the the symbols' content will not be recognized and play a
role in determining the Chinese output because this is in no way
dependent upon the person's knowledge of the symbols.  All that
matters with regard to the person is his knowledge of how to
correctly follow the rules.  Whether or not the *content* of this
symbols is recognized, is determined by the rules, and we simply have
no basis for concluding either way.  So, while the person hasn't the
slightest idea whether it would be better to eat, run away from, or
marry a "HAN-BAO-BAO", this knowledge may well be determined
through the application of the rules, and, in such a case, they
could dictate that an output be produced that takes account of this
recognition.  The output might well say, for example, that these
things are found at McDonald's, but it would be surprising in the
extreme to consider spending the rest of one's life with one.  The
person in the room is completely oblivious to this distinction, and
yet the Chinese symbols were indeed correctly recognized for their
CONTENT, and this happened WITHIN the room.

	On the other hand, it need not be the case that the meaning
of the symbols is determined at any point.  The same output could be
produced by a very different process (it is hard to imagine, though,
how the illusion could be maintained).  Thus, I agree that looking at
the I/O behavior outside of the room is not sufficient to determine
if the input symbols are being understood (mapped to their meanings),
or if, instead, they are treated as objects having form but no
content (or treated some other way for that matter).

	The argument that there is no understanding of Chinese
because the *person* never understands the input symbols appears to
be based on a failure to distinguish between a generic Turing Machine
(TM) and one that is programmable, a Universal Turing Machine (UTM).
A UTM, U, is a TM that is given as input the program of another TM,
T, and *its* input, x.  The UTM computes a function which is itself
the computation of a function of the input x.  Thus, the UTM *does
not* compute y = T(x); it computes y = U(T, x).  If T, as a parameter
of U, is held constant, then y = T(x) = U(x), but this still doesn't
mean that U "experiences x" the same way T does.  U merely acts as
an intermediary that enables T to process x; when T is done, U
returns T's result as if it were his own doing.  The rules that the
person is following are, in fact, a program for Chinese I/O (CLP).
The person is acting as a UTM.  He is following *his own set of
rules* that tell him what to do with the rules and inputs that he
receives.  Thus, the person's program is to execute the rules'
program on the inputs.  It is little wonder that the person may not
treat the input symbols in the same way that the rules treat them.
The real question that should be asked is NOT whether the person,
in following the rules, understands the Chinese characters, UC,
(clearly he does not), but whether the person would understand the
Chinese characters if HIS NEURONS were the ones implementing the
rules and he were experiencing the results.  In other words, the
rules may or may not DESCRIBE A PROCESS sufficient for figuring out
what the Chinese characters mean.  ("UC, or not UC", do you see?)

	If Searle's and Harnad's arguments were correct, then one
would be lead, as they seem to be, to the conclusion that a Turing
Machine alone is not sufficient to produce understanding, in
particular the understanding of Chinese.  This would amount to the
the claim that either,
	 A.  Understanding is not computable, i.e., it is not
achievable through anything that could be considered an algorithm,
a procedure, or any finitely describable method,
	=or=
	 B.  The Church-Turing Thesis is wrong.

For what it is worth, I don't agree with either position.  There is
absolutely no reason to be persuaded that (B) is true, and I take my
own understanding of English (and a little Chinese) as an existence
proof that (A) is false.


	Richard Yee
	(yee at cs.umass.edu)