Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!ubc-cs!fornax!jones
From: jones@fornax.UUCP (John Jones)
Newsgroups: comp.ai
Subject: Re: Sci. American AI debate: No Contest
Message-ID: <199@fornax.UUCP>
Date: 5 Jan 90 18:41:20 GMT
References: <12679@phoenix.Princeton.EDU>
Reply-To: jones@lccr.UUCP (John Jones)
Organization: School of Engineering Science, SFU, B.C., Canada
Lines: 63
Keywords: Searle Churchland Speed

Searle's Chinese Room argument appears to be based on sleight-of-hand:
we are presented with a system, containing a man and a book of rules, 
that produces appropriate responses to an arbitrarily large range of
questions.
Searle invites us to locate where the 'understanding' takes place.  Naturally we 
look first at the man -- whoever heard of a book understanding anything --
but the man assures us, through introspection, that he understands neither the
questions nor the answers.  Searle concludes that no understanding is taking
place.

One of the beauties of this argument is that it allows Searle to avoid any
definition of 'understanding'.  We know what it is like to understand something,
so introspection provides the sole and universal test for the presence of
understanding.  If we are faced with an entity of a new type, we have simply
to imagine ourselves in the place of that entity and introspect.

This criterion works well enough when the imaginative leap is small.
We can imagine ourselves into the place of the man in the Chinese room
easily enough, and we're quite confident in saying he doesn't understand.
The criterion discourages us from looking at the book -- we have no idea how
to put ourselves in the place of a book -- so we pass over the remarkable part 
of the system.  For this book is unlike any book that exists in the world.
It contains everything an intelligent adult Chinese knows about himself and
the world -- so it's a big book, perhaps comparable in size with the Library
of Congress -- but, far more remarkable, it contains rules that will allow
the reader to find the knowledge needed to answer an uninterpreted string
of signs and to compose that knowledge into another uninterpreted string
of appropriate length and form.  We have no idea what such rules might look
like.  And the only tool Searle offers us for evaluating the properties of
this book is introspection.

To make the adequacy of introspection more plausible, Searle has the man 
memorise the book.  Now we have a man who has memorised something he
doesn't understand.  We can imagine himself into his position easily enough,
we introspect, and, sure enough, we don't understand.

Other critics have pointed out that the man lacks the memory capacity to memorise
the book, and that, even if he were to memorise it, he could not respond to 
questions in real time.  Both these points are true, but irrelevant.  The reason
Searle's argument breaks down is that the man-plus-book is an entity unlike any
we have ever encountered, and we can no more imagine ourselves into his position 
than we can imagine ourselves to be a bat.

The inadequacy of imagination-plus-introspection as a criterion for understanding
can be demonstrated with less exotic examples than the Chinese room.
Consider one of the split-brain patients described by Sherrington.
Asked to describe an object that he is allowed to handle but not to see,
the patient can write down that it is a pipe, but states verbally that he
has no idea what it is.  This behaviour is no more extraordinary than might be
expected from the man-plus-book; Searle's criterion is no more helpful
in one case than in the other.

We have two alternative criteria for understanding; an operational criterion, 
such as the Turing test; and the imagination-introspection criterion proposed
by Searle.  It is, of course, meaningless to ask which criterion represents
true understanding.  I suggest, though, that by limiting us to entities we can
---
readily imagine ourselves in the place of, Searle guarantees that our use of the 
word 'understanding' will always be parochial and anthropocentric.  For this reason
I would prefer an operational criterion, and the Turing test seems as reasonable an
operational criterion as one could wish for.

                                                               John Dewey Jones