How many fingers?

An interesting piece on Skeptico (the one with the k is the bad one).

How do you prove photography to a blind man?

That was the question I was asked: how would you prove to a blind man, that photography exists?

I knew what he was getting at. We had been discussing psychics. He was a firm believer in psychic powers, had had psychic experiences, and regularly visited a psychic. His point was, since I had not experienced psychic powers, I would never be able to believe in what he “knew” to be true. You could never prove to a blind man that photography exists, and likewise no one would ever be able to demonstrate to me that psychic powers were real.

From here, they turns the argument on its ear.

First, they will show how in fact photography could be proven to exist through a long series of controlled tests run by the blind man.

Then, they take it farther. Offering the example as a way to show that, in fact, the failures of psychics is a valid reason to disbelieve.

It is a quite fun thought exercise and mental judo.

Wouldn’t the blind man say to all this, “why can’t you just tell me how many fingers I’m holding up?”