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SERGIU HART
a certain segment of each one, and at how these various segments from this great
number of disciplines fit together.
H: Can you give a few examples for the readers of this journal? They may be
surprised to hear about some of these connections.
A: I’ll try; let’s go through some applications. In computer science we have
distributed computing, in which there are many different processors. The problem
is to coordinate the work of these processors, which may number in the hundreds
of thousands, each doing its own work.
H: That is, how processors that work in a decentralized way reach a coordinated
goal.
A: Exactly. Another application is protecting computers against hackers who
are trying to break down the computer. This is a very grim game, just like war
is a grim game, and the stakes are high; but it is a game. That’s another kind of
interaction between computers and game theory.
Still another kind comes from computers that solve games, play games, and
design games—like auctions—particularly on the Web. These are applications of
computers to games, whereas before, we were discussing applications of games
to computers.
Biology is another example where one might think that games don’t seem
particularly relevant. But they are! There is a book by Richard Dawkins called
The Selfish Gene. This book discusses how evolution makes organisms operate as
if they were promoting their self-interest, acting rationally. What drives this is the
survival of the fittest. If the genes that organisms have developed in the course
of evolution are not optimal, are not doing as well as other genes, then they will
not survive. There is a tremendous range of applications of game-theoretic and
rationalistic reasoning in evolutionary biology.
Economics is of course the main area of application of game theory. The
book by von Neumann and Morgenstern that started game theory rolling is
called The Theory of Games and Economic Behavior. In economics people
are assumed to act in order to maximize their utility; at least, until Tversky
and Kahneman came along and said that people do not necessarily act in their
self-interest. That is one way in which psychology is represented in the Center
for Rationality: the study of irrationality. But the subject is still rationality. We’ll
discuss Kahneman and Tversky and the new school of “behavioral economics”
later. Actually, using the term “behavioral economics” is already biasing the issue.
The question is whether behavior really is that way or not.
We have mentioned computer science, psychology, economics, politics. There
is much political application of game theory in international relations, which we
already discussed in connection with Kissinger. There also are national politics,
like various electoral systems. For example, the State of Israel is struggling with
that. Also, I just came back from Paris, where Michel Balinsky told me about
the problems of elections in American politics. There is apparently a tremendous
amount of gerrymandering in American politics, and it’s becoming a really big
problem. So it is not only in Israel that we are struggling with the problem of how
to conduct elections.
INTERVIEW WITH ROBERT AUMANN
701
Another aspect is forming a government coalition: if it is too small—a minimal
winning coalition—it will be unstable; if too large, the prime minister will have
too little influence. What is the right balance?
Law: more and more, we have law and economics, law and game theory. There
are studies of how laws affect the behavior of people, the behavior of criminals, the
behavior of the police. All these things are about self-interested, rational behavior.
H: So that’s the Center for Rationality. I know this doesn’t belong, but I’ll ask
it here. You are a deeply religious man. How does it fit in with a rational view of
the world? How do you fit together science and religion?
A: As you say, it really doesn’t belong here, but I’ll respond anyway. Before
responding directly, let me say that the scientific view of the world is really just
in our minds. When you look at it carefully, it is not something that is out there in
the real world. For example, take the statement “the earth is round.” It sounds like
a very simple statement that is either true or false. Either the earth is round or it
isn’t; maybe it is square, or elliptical, or whatever. But when you come to think of
it, it is a very complex statement. What does roundness mean? Roundness means
that there is a point—the “center” of the earth—such that any point on the surface
of the earth is at the same distance from that center as any other point on the
surface of the earth. Now that already sounds a little complex. But the complexity
only begins there. What exactly do we mean by equal distance? For that you need
the concept of a distance between two points. The concept of distance between
two points is something that is fairly complex even if we are talking about a
ball that we can hold in our hands; it involves taking a ruler and measuring the
distance between two points. But when we are talking about the earth, it is even
more complex, because there is no way that we are going to measure the distance
between the center of the earth and the surface of the earth with a ruler. One
problem is that we can’t get to the center. Even if we could find it we wouldn’t be
able to get there. We certainly wouldn’t be able to find a ruler that is big enough.
So we have to use some kind of complex theory in order to give that a practical
meaning. Even when we have four points and we say the distance from A to B is
the same as the distance from C to D, that is fairly complex already. Maybe the
ruler changes. We are using a whole big theory, a whole big collection of ideas, in
order to give meaning to this very, very simple statement that the earth is round.
Don’t get me wrong. We all agree that the earth is round. What I am saying
is that the roundness of the earth is a concept that is in our minds. It’s a product
of a very complex set of ideas, and ideas are in people’s minds. So the way I
think of science, and even of fairly simple things, is as being in our minds; all the
more so for things like gravitation, the energy that is emitted by a star, or even the
concept of a “species.” Yes, we are both members of the species homo sapiens.
What does that mean? Obviously we are different. My beard is much longer than
yours. What exactly does species mean? What exactly does it even mean to say
“Bob Aumann” is sitting here? Is it the same Bob Aumann as five minutes ago?
These are very complex ideas. Identity, all those things that we think of trivially
on a day-to-day basis, are really complex ideas that are in our minds; they are not