This is a detail of Tintoretto’s “Tarquin and Lucretia” (1578-1580), which belongs to the Art Institute of Chicago but is now in Boston for the astounding exhibition entitled “Titian, Tintoretto, Veronese: Rivals in Renaissance Venice.” (Probably never before have so many comparable paintings by these competitors been hung together.)

In the detail, pearls are strewn across Lucretia’s clothes; Tarquin has just broken the strand. The spheres are caught on their way downward, spaced at growing intervals.

People have always known that objects move, and have always depicted motion in still images–since the ancient cave paintings. But I think Tintoretto’s painting may reflect a new way of thinking about motion and space. The image represents a precise instant at which each pearl would occupy a different and predictable location because of the mathematical laws of nature. The objects are frozen, but their locations allow us to infer their movement.

Galileo revolutionized science by claiming that nature was a book written in the language of mathematics. Tintoretto painted Galileo’s portrait from life in 1605-7, which shows that the two geniuses knew each other. By 1638, Galileo had proved (either in a real experiment on the Tower of Pisa, or in a thought-experiment) that objects of different weights would fall at the same accelerating rate. And forty years later, Tintoretto was interested enough in this Galilean conception of time and space that he painted pearls accelerating down Lucretia’s chest. It was another thought-experiment.

In Tiepolo’s “St. Dominic Instituting the Rosary” (1737-9), the rosary itself plummets at high speed from an enormous sky painted on the ceiling of the Gesuati Church in Venice. That is an excellent example of baroque theatricality, but not a unique one. By then, Europeans automatically thought of motion in Galilean terms. Tintoretto was perhaps the first to paint that way.

Mr. Huang is a youngish artist who uses cheap, discarded objects (soda bottles, baggies) and electronic components such as motion-detectors, LEDs, and fans to create objects that seem animal. My family and I saw his installation at RISD this weekend. It was like a whimsical aquarium; anemone-like creatures on the floor deflated their plastic bags shyly when you walked near them, and the big jelly-fish-like thing in the middle turned to watch you with its human eyes. It all sounds like something that Pixar or Disney would create. I respect their talents, but Huang is a studio artist rather than an entertainer, and I think the difference has to do with the following factors. He has a sense of humor but doesn’t play for laughs. His use of banal waste products to make lovely organic objects stimulates subtle ideas about nature and human action without driving home an obvious point. He leaves the wiring and electronic gadgets unconcealed; there’s no pretense to being something other than an art installation. Most important, Huang is a fine and careful individual craftsman. My little daughter and I were inspired to make something somewhat similar when we got home, and I developed a sense of how remarkably hard it would be to copy a Huang.

This painting, from about 1690, is one of my favorites in our new home town of Boston. (It’s in the Museum of Fine Arts.) The “Rest on the Flight to Egypt” is an old subject for paintings, going back to the middle ages. It illustrates Matthew 2:12-14:

And being warned of God in a dream that they should not return to Herod, they departed into their own country another way. And when they were departed, behold, the angel of the Lord appeareth to Joseph in a dream, saying, Arise, and take the young child and his mother, and flee into Egypt, and be thou there until I bring thee word: for Herod will seek the young child to destroy him. When he arose, he took the young child and his mother by night, and departed into Egypt.

For some reason that I don’t know, artists have (for many centuries) chosen to depict the little family pausing on the way to Egypt. That makes an acceptable subject for a Protestant, because it’s a “history painting”–an illustration of something that really happened, according to the Bible. In contrast, a painting of the “Holy Family” or the “Virgin and Child with Saints” would be problematic from a Protestant perspective. Those extremely common subjects developed as Orthodox and Catholic devotional objects, as icons or stimuli to prayer and meditation. For Protestants, they verge on “graven images.”

De Gelder (a student of Rembrandt) was a Protestant, but he has found a way here to imitate a “Holy Family” or a “Madonna and Child with Saint.” Joseph resembles St. Jerome in a painting of a sacra conversazione. And (as my wife Laura notes) the Madonna’s halo has migrated onto Mary’s extraordinary circular, gold-rimmed hat.

I take no sides in the Protestant/Catholic debate about religious images. But I think the shift from a Madonna and Child to a history painting has produced wonderful effects in this particular work. Since the baby is not an object of veneration, he can act like a real infant–snuggling down into his mother’s lap instead of being displayed upright. Joseph reads a grown-up book, presumably for the edification of the adults in the family–but he pauses to gaze affectionately at his newborn (holding his place with his finger). It’s an affectionate representation of a human family, with subtle echoes of the grand Catholic tradition.

I recently read Kenneth Grahame’s classic to my 9-year-old. As you may remember, Toad is the heir to the local manor and fortune and the one character in the neighborhood with an advanced education. He begins as an awful person–arrogant, selfish, pretentious, wasteful, lazy, and a menace on the road. He takes some hard knocks and finally learns to be a good squire. His transformation is shown by two major signs: his behavior at a banquet in his own Hall, and his friendships. Whereas in the bad old days Toad used to make risibly arrogant speeches at dinner parties, the new Toad, “by pressing delicacies on his guests, by topical small talk, and by earnest inquiries after members of their families not yet old enough to appear at social functions, managed to convey that this dinner was being run on strictly conventional lines.” Meanwhile, he shows genuine respect and admiration for his three main friends–the acknowledged best of whom, Mr Badger, speaks with a notably uneducated accent and dresses roughly.

(As for Toad’s friend Mole–he is a wonderful caricature of a provincial middle-class suburbanite. “On the walls [of his garden] hung wire baskets with ferns in them, alternating with brackets carrying plaster statuary–Garibaldi, and the infant Samuel, and Queen Victoria, and other heroes of modern Italy.”)

This is a conservative vision. No one gains any rights vis-à-vis Mr. Toad. He is not compelled to act better, nor to renounce any of his wealth or prestige. He isn’t (for example) taxed to fund better education for the myriad little rabbits who live in the Wild Wood. Instead, he helps to restore the ancient social equilibrium by acting responsibly and generously and thereby winning the respect of the neighborhood.

It’s not my ideal. I’m glad the real Mr. Toads of England had to pay inheritance taxes, and the real Moles and Rats got subsidized access to higher education. But The Wind in the Willows has a moral core as well as charm. In our era of billionaire celebrity heiresses, we could do worse.