Most of Browning's poems are written in the voice of a speaker who is not the poet (Browning hardly ever wrote in his own voice); in this case, the story is told to the primary speaker by his uncle, a ferocious anti-Semite who detests the increasing tolerance and acceptance of Jews in Florence ("I fear we must not pelt the Jews!") and the "laws, which modern fools enact" in favour of tolerance. To illustrate his point about the devious trickery of the Jews, he tells his nephew a story, but as often in Browning, the point the reader takes from the story is different from the point the speaker thinks he's making.
The basic idea of the story is that a Jewish cemetary adjoins the property of an affluent, anti-semitic farmer. To "gall the unbelievers," the farmer hires the painter Ludovico Buti to create a painting of the Virgin Mary and place it facing the cemetary, so the Jews will have to see the Virgin Mary every time they hold a funeral. When the Jews object, the farmer tells them he'll turn the picture around in exchange for 100 ducats -- and then, when they pay him, hires Buti again to create a painting of Jesus on the other side of the canvas.
A young Jewish man, the son of a woman who was just buried in the cemetary (and whose funeral was ruined by the sight of Buti's painting) arrives at the farmer's house. But he doesn't want to fight, as the cowardly farmer and painter both assume; instead he offers to buy the painting to hang in his house. The farmer accepts the offer and assumes that he has made a convert:
The Farmer—who, though dumb, this while
Had watched advantage—straight conceived
A reason for that tone and smile
So mild and soft! The Jew—believed!
But the purchaser sets him straight: he wants the painting as a work of art, nothing more. He recalls seeing paintings of Greek gods in the home of prominent Christians, and wondering why they would display pagan gods in their homes. The answer he received was that the paintings are displayed for their artistic value only, not as religious works.
“‘Benignant smiles me pity straight
The Cardinal. ’Tis Truth, we prize!
Art’s the sole question in debate!
These subjects are so many lies.
We treat them with a proper scorn
When we turn lies—called gods forsooth—
To lies’ fit use, now Christ is born.
Drawing and coloring are Truth.
“‘Think you I honor lies so much
As scruple to parade the charms
Of Leda—Titian, every touch—
Because the thing within her arms
Means Jupiter who had the praise
And prayer of a benighted world?
He would have mine too, if, in days
Of light, I kept the canvas furled!’
And so, the purchaser concludes, he will apply the same principle to the pictures of Christ and Mary that Christians apply to pictures of Leda and Jupiter: as artistic representations of mythological figures, to be praised or scorned based on artistic considerations only, with the religious figures accorded no more respect than a Christian would give a Greek religious figure:
“‘So ending, with some easy gibe.
What power has logic! I, at once,
Acknowledged error in our tribe
So squeamish that, when friends ensconce
A pretty picture in its niche
To do us honor, deck our graves,
We fret and fume and have an itch
To strangle folk—ungrateful knaves!
“‘No, sir! Be sure that—what’s its style,
Your picture?—shall possess ungrudged
A place among my rank and file
Of Ledas and what not—be judged
Just as a picture! and (because
I fear me much I scarce have bought
A Titian) Master Buti’s flaws
Found there, will have the laugh flaws ought!’
The man leaves with the picture, leaving the farmer nonplussed. The uncle ends the story by ranting about the breakdown of religious repression and the evils of a society that tolerates tolerance:
“Was magic here? Most like! For, since,
Somehow our city’s faith grows still
More and more lukewarm. and our Prince
Or loses heart or wants the will
To check increase of cold. ’Tis ‘Live
And let live! Languidly repress
The Dissident! In short,—contrive
Christians must bear with Jews: no less!’
“The end seems, any Israelite
Wants any picture,—pishes, poohs,
Purchases, hangs it full in sight
In any chamber he may choose!
In Christ’s crown, one more thorn we rue!
In Mary’s bosom, one more sword!
No, boy, you must not pelt a Jew!
O Lord, how long? How long, O Lord?”
As with a lot of Browning's poems, he doesn't specifically tell you what meaning to take from the poem, and there are multiple ways to interpret it. Certainly it's not just about 17th-century Italy; there were plenty of people like the uncle in Browning's time, and today. The idea that art should be judged on its own merits as art and not as religious statements (or political statements) is certainly not something that ever goes away, though Browning is ambiguous about where he comes down on this issue. Is the uncle right -- for the wrong reasons -- in thinking that decoupling art from religious/political significance robs it of its ability to foster intolerance, and therefore creates a more tolerant society over time? Browning is certainly not with the uncle in thinking that intolerance is a good thing, but he might be putting inadvertent truth into the villain's mouth. Or is Browning less than enthusiastic about the idea of using art to make religious/political points, since it winds up backfiring on the person who tries to make the point (as it backfires on the other villains of the piece, the farmer and Buti)? Is it a celebration of the democratic nature of art -- because anyone can enjoy it, whatever their race or religioun or creed, good art is not exclusionary -- or is it more about religious intolerance than about art? The answer to all these questions, as always with a Browning poem, is "yes." He never tells you exactly what he thinks the primary point of a poem is, but he lets all kinds of themes emerge and butt up against each other -- that's what makes his poetry so interesting.