A reader once asked me what I thought were the major turning points of art – by which he meant the Euro-American tradition in art from the Renaissance to the 20th century. Of course, he had his own list already prepared to share with me. On it were 20 items. He wanted to know what would be on my list. He had the enthusiasm of a puppy dog, and it would have felt churlish to refuse him.

Making it a list of 20 is, of course, arbitrary: There are hundreds, maybe thousands of “turning points” in art history.

Also, we must confess this is a parochial list, when you have the rest of the world and antiquity — to say nothing of prehistory — to consider. But that bobsled ride from the Renaissance to Postmodernism can be seen as a single unit, and that is what my reader wanted me to consider.

Off the top of my head, then, are the 20 most pivotal pieces of art, each of which could be a chapter heading in an art history text.

Admittedly, they function as epitomes. It is rare a single piece of art can change the course of art history; instead, they are stand-ins for whole movements in art, entire changes of esthetic outlook and purpose that propel the eras they helped codify or inaugurate.

But even given my guidelines, I had to start a bit earlier, because the reawakening of Europe after the Dark Ages doesn’t happen in Renaissance Italy, but in Gothic northern Europe.

My list begins with the north rose window at Chartres – the single most beautiful thing I’ve ever seen from the hand of humankind. Actually, the list should begin with the basilica of St. Denis in Paris, the first truly Gothic church, and the inspired conception of Abbot Suger, one of the most important clerics of the 11th century. His Neoplatonist idea was that God was light and that a church, to capture the spirit of divinity, must be opened up with windows and color. The engineering was a breakthrough: He realized that you don’t need walls – the heavy stone walls of the Romanesque – to hold up a roof, but you could put the roof on pillars and fill in the space between the pillars with curtains of colored glass. It was a huge step forward esthetically and technologically. But St. Denis was a first draft: It is in Chartres that the ideal finds its apotheosis.

Second, Giotto’s interior frescoes for the Arena Chapel in Padua, for waking up to the idea that painting not only could, but should try to capture something of the feel of reality.

Third, the Trinity of Masaccio at the Sta. Maria Novella in Florence. It’s impossible to choose the single image that represents the triumph of Renaissance perspective over the Gothic style, but Masaccio is as good a choice as anyone.

Fourth: The bronze doors of Ghiberti to the Baptistry in Florence, an astonishing display of inventiveness and naturalistic imagery.

Fifth: The David of Donatello, and the final destruction of the Gothic schema in Western art.

Sixth: The David of Michelangelo Buonarroti, and

Seven: The Sistine ceiling. No artist so defined his age and the two hundred years after him more than Michelangelo, the single most influential artist in history.

Eight: Caravaggio: The Calling of St. Matthew, although most of the crazy guy’s central paintings would do: The Invention of the Baroque. “Energy is eternal delight,” as Blake says.

Nine: The David (above) of Gianlorenzo Bernini (although I actually prefer the Apollo and Daphne), and the perfection of the Baroque, and the most proficiently perfect sculptor in history. I choose the David only for the symmetry with Donatello and Michelangelo. Look at the three Davids together and see the direction of the 15th and 16th centuries.

10: Rembrandt Portrait of the Syndics of the Cloth-maker’s Guild, (chosen over the more flamboyant Night Watch) to show how the psychological acumen of the Dutchman could bring life to an otherwise utterly conventional group portrait. This sense of psychology, that there is a real person behind the eyes, is what Rembrandt brought to painting, as Shakespeare brought it to the stage.

11: The Death of General Wolfe by Benjamin West, which manages to turn the conventions of the mythological painting onto not merely the historical event, but the current event. In a way, each of these choices is a step on a road from stylization and convention to a more aware and awake attempt to engage with the experience of being alive, with what we might call a more “real” vision of the world.

12: Liberty on the Barricades by Eugene Delacroix, although you could also use Greece Expiring on the Ruins of Missolonghi, as the symbolic use of politics and the rise of the democratic spirit in the world.

13. Joseph Mallord William Turner’s The Slave Ship as another political comment, but more important as the first glimmerings of a kind of Impressionism in paint, and the turning point where what we now call Modernism has not its birth, but at least its conception.

14. Edouard Manet, The Fife Player, as the birth of that Modernism, flat, ironic, oblique.

15. Paul Gauguin, Where Do We Come From? What Are We? Where Are We Going? and the continuing flattening of picture space, at the same time as opening up to non-Western pictorial influences — to say nothing of questioning the values of European civilization, and it’s about time.

16. Pablo Picasso, Demoiselles d’Avignon as the source of Cubism, and the sense that the picture is a canvas and not a window. It was the single most revolutionary painting of the 20th century, although in retrospect, not Picasso’s best.

17. Fountain by Marcel Duchamp – the “found object” urinal – and the single most influential sculpture of the 20th century, and an influence that is still oppressive today. Now, everyone thinks he’s Duchamp.

18. I would also include Picasso’s Guernica in this list, as his most ambitious work and the single most powerful image of the 20th century. I grew up with this mural size scream, when it was at MOMA in New York and I was a kid. It is the perfect meld of technique, imagery, symbol and “message.”

19. Andy Warhol’s Campbell Soup Can and the rise of Pop. Warhol is the most serious postwar American artist, despite his public antics. Art is about the world we live in; Warhol reminds us that the world we currently inhabit is the one of commercial signage and media imagery.

20. Finally, Joseph Beuys How to Explain Pictures to a Dead Hare, or any of a dozen other Beuys pieces, angry yet detached, symbolic yet utterly there physically as a presence. The most influential European artist of the postwar years.

This list is, of course, just off the top of my head. I’m sure if I gave it deeper thought, I’d switch out some of these choices. But this is a good enough start.

I’m sure you can think of things I’ve missed.