Poetry is a dream dreamed in the presence of reason.*
~ Tommasso Ceva
* Edward Hirsch references this dictim in his How to Read a Poem: And Fall in Love with Poetry (this book can be found at GoogleBooks).
Tommaso Ceva (1648-1737), Jesuit Mathematician and Poet
Harvard Diary on Iesus Puer by Tommaso Ceva at Italica