We cut nature up, organize it into concepts, and ascribe significances as we do, largely because we are parties to an agreement to organize it in this way - an agreement that holds through our speech community and is codified in the patterns of our language.
If you can't read and write you can't think. Your thoughts are dispersed if you don't know how to read and write. You've got to be able to look at your thoughts on paper and discover what a fool you were.