Here's an entry I made in my poetry journal I don't know how many years ago.
“… for whatsoever the philosopher saith should be done, he [the poet] giveth a perfect picture of it in some one, by whom he presupposeth it was done. So as he coupleth the general notion with the particular example. A perfect picture I say, for he yieldeth to the powers of the mind, an image of that whereof the philosopher bestoweth but a wordish description: which doth neither strike, pierce, nor possess the sight of the soul, so much as the other doth.” (Sir Philip Sidney, “An Apology for Poetry.” )
For Sidney, poetry had two primary functions—to delight and to teach—which made it superior to both philosophy and history. Philosophy presented truths and virtues unadorned, plainly, which made them non memorable. History was restricted by the necessity to show what was done rather than what should be or should have been done. That does not mean that philosophy or history do not have their value. But poetry can do what neither of them can. Sidney uses Christ’s parable of Dives and Lazarus—the one in hell, the other in the bosom of Abraham – to illustrate his point. Christ could have given a straight forward definition of greed or of virtue. But the lecture would not stay in the mind in the same way as the images of the stories he told. Because they delighted, they could also teach. [A particularly interesting phrasing and one that might bear more explication when looking at 20th century poetry is that philosophy teaches those who are already learned. Poetry teaches the innocent.] To illustrate his point about history, he asks where one would look for virtue -- to a historian's representation of Alexander, considering the historian is bound to tell both good things and bad things that happened, or to the poet’s representation of Ulysses or Achilles.