Page 74 - The Art and Science of Analog Circuit Design

Richard P. Feynman

with lots of good materials, and they want the same thing to happen now.
So they've arranged to make things like runways, to put fires along the
sides of the runways, to make a wooden hut for a man to sit in, with two
wooden pieces on his head like headphones and bars of bamboo sticking
out like antennas—he's the controller—and they wait for the airplanes to
land. They're doing everything right. The form is perfect. It looks exactly
the way it looked before. But it doesn't work. No airplanes land. So I call
these things cargo cult science, because they follow all the apparent pre-
cepts and forms of scientific investigation, but they're missing something
essential, because the planes don't land.
Now it behooves me, of course, to tell you what they're missing. But it
would be just about as difficult to explain to the South Sea Islanders how
they have to arrange things so that they get some wealth in their system.
It is not something simple like telling them how to improve the shapes of
the earphones. But there is one feature I notice that is generally missing
in cargo cult science. That is the idea that we all hope you have learned
in studying science in school—we never explicitly say what this is, but
just hope that you catch on by all the examples of scientific investigation.
It is interesting, therefore, to bring it out now and speak of it explicitly.
It's a kind of scientific integrity, a principle of scientific thought that cor-
responds to a kind of utter honesty—a kind of leaning over backwards.
For example, if you're doing an experiment, you should report everything
that you think might make it invalid—not only what you think is right
about it: other causes that could possibly explain your results; and things
you thought of that you've eliminated by some other experiment, and
how they worked—to make sure the other fellow can tell they have been
eliminated.
Details that could throw doubt on your interpretation must be given, if
you know them. You must do the best you can—if you know anything at
all wrong, or possibly wrong—to explain it. If you make a theory, for
example, and advertise it, or put it out, then you must also put down all
the facts that disagree with it, as well as those that agree with it. There is
also a more subtle problem. When you have put a lot of ideas together to
make an elaborate theory, you want to make sure, when explaining what
it fits, that those things it fits are not just the things that gave you the idea
for the theory; but that the finished theory makes something else come
out right, in addition.
In summary, the idea is to try to give all of the information to help
others to judge the value of your contribution; not just the information
that leads to judgment in one particular direction or another.
The easiest way to explain this idea is to contrast it, for example, with
advertising. Last night I heard that Wesson oil doesn't soak through
food. Well, that's true. It's not dishonest; but the thing I'm talking about
is not just a matter of not being dishonest, it's a matter of scientific in-
tegrity, which is another level. The fact that should be added to that ad-
vertising statement is that no oils soak through food, if operated at a

57