Full Idea
Poetry is something more philosophic and of graver import than history, since its statements are rather of universals, whereas those of history are singulars.
Gist of Idea
Poetry is more philosophic than history, as it concerns universals, not particulars
Source
Aristotle (The Poetics [c.347 BCE], 1451b05)
Book Reference
Aristotle: 'The Basic Works of Aristotle', ed/tr. McKeon,Richard [Modern Library Classics 2001], p.1464
A Reaction
Hm. Characters in great novels achieve universality by being representated very particularly. Great depth of mind seems required to be a poet, but less so for a historian (though there is, I presume, no upward limit on the possible level of thought).