I don't think Plato would count a book as an intelligible thing. Intelligible things are forms and axioms - logic/logos is a level above that.

So my answer is No, but I'm open to correction.

Anyways, my point was only that great thinking is original thinking. Plato probably couldn't have been Plato if he had read Nietzsche first (not even counting the fact that Nietzsche hated Plato).