Page 97 - Foundations of Cognitive Psychology : Core Readings

98 John R. Searle

irrelevant to my understanding of the story. In the Chinese case I have every-
thing that artificial intelligence can put into me by way of a program, and I
understand nothing; in the English case I understand everything, and there is
so far no reason at all to suppose that my understanding has anything to do
with computer programs, that is, with computational operations on purely
formally specified elements. As long as the program is defined in terms of
computational operations on purely formally defined elements, what the ex-
ample suggests is that these by themselves have no interesting connection
with understanding. They are certainly not sufficient conditions, and not the
slightest reason has been given to suppose that they are necessary condi-
tions or even that they make a significant contribution to understanding. Notice
that the force of the argument is not simply that different machines can have
the same input and output while operating on different formal principles—that
is not the point at all. Rather, whatever purely formal principles you put into
the computer, they will not be sufficient for understanding, since a human will
be able to follow the formal principles without understanding anything. No
reason whatever has been offered to suppose that such principles are necessary
or even contributory, since no reason has been given to suppose that when I
understand English I am operating with any formal program at all.
Well, then, what is it that I have in the case of the English sentences that I do
not have in the case of the Chinese sentences?The obvious answer is that I
know what the former mean, while I haven’t the faintest idea what the latter
mean. But in what does this consist and why couldn’t we give it to a machine,
whatever it is?I will return to this question later, but first I want to continue
with the example.
I have had the occasion to present this example to several workers in artifi-
cial intelligence, and, interestingly, they do not seem to agree on what the
proper reply to it is. I get a surprising variety of replies, and in what follows I
will consider the most common of these (specified along with their geographic
origins).
But first I want to block some common misunderstandings about ‘‘under-
standing’’: in many of these discussions one finds a lot of fancy footwork about
the word ‘‘understanding.’’ My critics point out that there are many different
degrees of understanding; that ‘‘understanding’’ is not a simple two-place
predicate; that there are even different kinds and levels of understanding, and
often the law of excluded middle doesn’t even apply in a straightforward way
to statements of the form ‘‘x understands y’’; that in many cases it is a matter
for decision and not a simple matter of fact whether x understands y; and so on.
To all of these points I want to say: of course, of course. But they have nothing
to do with the points at issue. There are clear cases in which ‘‘understanding’’
literally applies and clear cases in which it does not apply; and these two sorts
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of cases are all I need for this argument. I understand stories in English; to a
lesser degree I can understand stories in French; to a still lesser degree, stories
in German; and in Chinese, not at all. My car and my adding machine, on the
other hand, understand nothing: they are not in that line of business. We often
attribute ‘‘understanding’’ and other cognitive predicates by metaphor and
analogy to cars, adding machines, and other artifacts, but nothing is proved by
such attributions. We say, ‘‘The door knows when to open because of its photo-