# [Haskell-cafe] Sets and Universe. Was : "Very freaky"

jerzy.karczmarczuk at info.unicaen.fr jerzy.karczmarczuk at info.unicaen.fr
Thu Jul 12 17:47:57 EDT 2007

```Andrew Coppin:

>>> How come the set of all sets doesn't exist?

... Felipe Almeida Lessa cites a relevant page

> Ouch.
> Clearly, set theory is way more complicated than people make out. (I
> always thought a "set" was just a collection of objects...)

You are right. A set is a collection of objects, nothing more, provided you
know what is a collection, what is an object, and what is the meaning of
the verb "is".

Since this is a café chat, I'll tell you a Zen story. A young apprentice
thinks that an apple is just an apple.

But then, he starts studying.
One day he gets his enlightment, and learns that an apple is a terribly
complicated entity. There are concrete apples, there is also an idea
of an apple, a "universal apple". He knows then that his apple is a symbol
which hides inside the secret of the structure of our knowledge about
things. He feels humble facing his apple, and yet happy that he could
grasp some of its mysteries. The question "what is an apple" is an
infinite source of other questions which lead him to the Wisdom.

Seeral years later he becomes a Master.
Now, he sees clearly that an apple holds also the knowledge about the
structuration of the Unverse. His apple allows him to ask questions about,
say, limit of things: where this apple begins? What does it mean "inside"?
How to distinguish an apple from a non-apple? Can we ask where there are
two identical apples?

... When the Master gets older, he sees also that apples hold the secrets
of life and death. They symbolize - if one wants to see it - the Eternal
Ring of perpetuation of things. You must destroy your apple in order to
let grow new ones.

... et caetera.

++

Finally, our hero becomes a Great Master, a true one.
He looks at the universe below him, and he sees, as clearly as never
before, that an apple is just an apple...

Jerzy Karczmarczuk

```