Many are the noble words in which poets speak concerning the actions of men; but like yourself when speaking about Homer, they do not speak of them by any rules of art: they are simply inspired to utter that to which the Muse impels them, and that on...
The reason is that they utter these words of theirs not by virtue of a skill, but by a divine power - otherwise, if they knew how to speak well on one topic thanks to a skill, they would know how to speak about every other topic too.
The poet is a light and winged and holy thing, and there is no invention in him until he has been inspired and is out of his sneses, and the mind is no longer in him.