Word.

The landscape of the human mind was not formed through language but through literature. Language alone could never have done it.

All that we can grasp and comprehend, the vocabulary of ideas needed to lift our concerns from the local fishes, roots and berries and fling them up out into to the physical cosmos and the dizzier metaphysical realms - this does not come from being able to grunt or squeak meanings to our immediate neighbor! This comes from being able to consider an accumulation of ideas, built up over centuries of thought. To read, re-read, reflect. And then, to look farther and build upon - or challenge, and tear down.

When it comes to what separates our minds from those of the animals, it is not mere language. It is not the word we speak to one another. It is the word spoken to eternity.

Kira: What's writing?
Jen: Words that stay. My master taught me.

- The Dark Crystal