I think this famous dictum is correct as far as it goes. But poets of truly outlandish genius go way beyond petty thievery. They think themselves licensed to pillage nothing less than all of the world’s literature.
Consider William Shakespeare, whose thefts are legion. We’ve all heard about how he stole most of his stories. For example, he brazenly snatched the plot of Pericles from a novel by Robert Greene, who on his deathbed some years earlier had fulminated against a certain conceited young “upstart crow” who fancied himself “the only Shake-scene in a country.”
But Shakespeare didn’t stop at stealing overall plots. He grabbed up specific passages by others seemingly pell-mell and did whatever he liked with them. Let’s look this speech from Antony and Cleopatra, in which Enobarbus describes Antony’s first glimpse of Cleopatra upon the river Cydnus …
The barge she sat in, like a burnished throne,
Burned on the water; the poop was beaten gold;
Purple the sails, and so perfumed that
The winds were love-sick with them; the oars were silver,
Which to the tune of flutes kept stroke, and made
The water which they beat to follow faster,
As amorous of their strokes.
… the poope whereof was of gold, the sailes of purple, and the owers of silver, which kept stroke in rowing after the sounde of the musicke of flutes …
Resemblances sharpen as Enobarbus starts describing Cleopatra herself …
For her own person,
It beggared all description: she did lie
In her pavilion, cloth-of-gold of tissue,
O’erpicturing that Venus where we see
The fancy outwork nature.
… again echoing Plutarch …
And now for the person of her selfe: she was layed under a pavilion of cloth of gold of tissue, apparelled and attired like the goddess Venus, commonly drawen in picture …
And so Enobarbus continues for some seventeen lines, matching North’s Plutarch pretty much image after image.
Similar thievery can be found in Prospero’s climactic speech in The Tempest …
Ye elves of hills, brooks, standing lakes, and groves …
Ye Ayres and windes: ye Elves of Hilles, of Brookes, of Woods alone,
Of standing Lakes …
Again, the parallels continue for some seventeen lines.
I’m not griping. None of us should. Indeed, we really must rejoice. Shakespeare’s was more than the “honorable kind of thievery” mentioned in Two Gentlemen of Verona; it was truly noble thievery — Promethean, even. He stole liberally from the vast stores of human letters, transformed cold brass plunder into fiery gold, then handed this augmented treasure down to the poor in spirit — namely us.
Shakespeare also knew when to jettison his sources and let fly with his own preternatural eloquence. Prospero’s speech culminates in a poignant farewell to magic, which according to legend was Shakespeare’s own farewell to his art. You won’t find anything like it in Ovid …
But this rough magic
I here abjure; and when I have required
Some heavenly music (which even now I do)
To work mine end upon their senses that
This airy charm is for, I’ll break my staff,
Bury it certain fathoms in the earth,
And deeper than did ever plummet sound
I’ll drown my book.