COVER YOUR LEFT EYE, put your face close
to the screen, and look at the X. As you slowly pull your face
away from the screen, at some point the 0 will disappear. Or
cover your right eye and look at the 0, and pull away, and the
X will disappear.
You have a blind spot in each eye where
the bundles of nerve fibers go back into your brain. But notice
something: You dont see the blind spot. It doesnt
show up like a dark, empty spot. Your brain fills in the emptiness.
In a similar way, when there is information
you dont know, your brain fills it in, giving you
the feeling that nothing is missing. In other words, when you
feel certain, it doesnt really mean much. Your feeling
of certainty doesnt necessarily have any relationship to
your actual correctness or knowledge. Your brain produces a feeling
of certainty at the drop of a hat because its wired up
to do so.
All human brains tend to jump to conclusions
and then feel certain about those conclusions, so it pays to
be somewhat skeptical of your own mind. That may seem like a
negative goal, but it isnt. Feeling certain has caused
more problems for people than skepticism ever did.
For example, when youre arguing with
your spouse, the thing that keeps the anger intense is that youre
both certain youre right. If each of you had a little
more skepticism about your own ability to remember and reason,
it would be easier to work out your differences.
To take another example, depressed people
would get depressed less often if they became more skeptical
of the pessimistic assumptions they make. The feeling of certainty
depressed people have about their own pessimistic view of the
world does them harm.
Dont place much importance in your
feelings of certainty. Be skeptical. Recognize you have blind
spots and act accordingly. Youll be saner if you do.
Be skeptical of your feelings