They don't have opposable thumbs, so they won't be able to write much.

He'll have to hold it with his mouth.

>>2575
Cats don't write. They have human servants for that.

My cat's stolen my pen before. I assumed he just wanted to play with it.

>>2579
Well in fact he was writing the first draft of his novel, and is now a published author.

Get some masking tape.
Cut 4 lengths each about a foot long.
Stick them to the carpet in the shape of a square.
Cat will sit in it.