Translated from Italian by me (WTFPL).
Imagination, as I have said, is the primary source of human happiness. The more it reigns in a person, the happier that person will be. We see this in children. But it cannot reign without ignorance, at least a certain ignorance, like that of the ancients. The knowledge of truth, that is, of the limits and definitions of things, constrains imagination.
Giacomo Leopardi – Zibaldone