The High Italian Renaissance sees a shift from Florence to Rome; this is due to the Papacy becoming a major patron and exile of the Medici family from Florence and move to Rome. High Italian Renaissance art is defined by exhibiting an increased emphasis on idealization, harmony, and beauty.

We're in Santa Maria delle Grazie in Milan, looking at Leonardo da Vinci's Last Supper. And we're in the room where the monks would eat, the refractory. And so several times a day, the monks would come in here and eat silently and be able to look up at Leonardo's Last Supper. 

It's an ideal place, of course, for this particular subject and not an uncommon one.

So let's talk about the story. At the Last Supper, Christ says, "One of you will betray me" to his 12 apostles. And one of the ways that this painting is often read is not the moment when Christ utters that, but the moment after when the reaction takes place. These are his closest followers. 

And so we see the shock at hearing these terrible words from Christ. "Is it I," they ask, "Is it I Lord, who will betray you?" 

And so what we see is this incredible set of reactions from the apostles around the table. 

So that's one way we can understand the fresco. But there's another aspect of the narrative. 

Christ, you can see, is reaching towards both a glass of wine and towards bread. And this is the institution of the sacrament. 

The sacrament of the Eucharist, where Christ says, "Take this bread for this is my body. Take this wine for this is my blood, and remember me." And you can see that he reaches out toward the bread and the wine. 

But what's interesting is that Christ's hand is widely spread, so it seems as if he's reaching towards the wine, but at the same time, he's reaching toward a bowl. And at the same moment Judas is reaching towards that same bowl.

Judas is the one who's going to betray Christ. He's been paid 30 pieces of silver by the Romans, and you can see he's grasped that bag of silver in his right hand as he pulls away from Christ, his face cast in shadow. But he's pulling away at the same time that he's still reaching out to the bowl, and that's one of the ways that Christ identifies who will betray him, the person who shares, who dips with him in that bowl.

So Leonardo tells us several moments in this story. And at the same time gives us a sense of the divine eternal importance of this story. I mean, we would never mistake this for 13 people having dinner; we know that this is an important moment, without any of the obvious symbols of the divine that we would have in the early Renaissance, like the halo. 

The figures themselves are monumental in this space, and too crowded for that table, creating a kind of energy, a kind of chaos that surrounds the perfection, the solemnity, the geometry of Christ. 

Christ forms an equilateral triangle. His head is in the center of a circle. The window that frames his head reads as a halo; there's that calm center. And then human beings with all of their faults, and fears, and worries around that divine center.

This is Leonardo da Vinci, who is thinking about mathematics; he's thinking about science. He's thinking about the integration of all of these things. If we look at earlier images of the Last Supper, there's lots of room at the table; there's lots of decorations in the room. What Leonardo does is he simplifies everything and focuses us on those figures and their gestures. And by making it so that there's no room behind the table, the figures take up so much space. It's separating our world from the world of Christ and the apostles, there's no way for us to enter that space. In fact, there's no way for them to move into our space, there really is this demarcation.

 In versions of Last Supper that Leonardo would've seen in Florence, Judas is sitting on the opposite side of the table. And by putting Judas with the other apostles, he does use the table as a barrier between our world and the world of the apostles. Let's look at those faces for just a moment. Christ is so serene; his eyes are down. One hand is up, one hand is down. To his right is a group of three. And there is Judas who's facing away from us in shadow. His neck is turned, reminding us that that night he will hang himself. Now, as he pulls away, St. Peter, Christ's protector, rushes in. He's got a knife that he holds around his back and he comes in seeming to say almost, "Who is it? I need to defend you." The third figure in that group with Judas and Peter would be St. John who looks very resigned and closes his eyes. And that's the tradition and paintings of the Last Supper.

My favorite three figures are the figures on the far right. Leonardo was very interested in using the body to reveal the soul, to reveal one's internal nature. But Leonardo was creating these four groups of three, that idea of knitting the figures together, overlapping them with one another, creating all this drama. 

And creating tensions and contrast between the emotional responses of all these figures is that incredible grouping of Thomas pointing upward. 

As if to say, "Is this something that is ordained by God? Is this God's plan that one of us should betray you?" 

But of course, that finger also foreshadows him, actually proving Christ's resurrection by plunging that finger into Christ's wound. And then we have Philip and James the Major, and they're in opposition: one throwing his arms out, one bringing his hands together.

 And if we were to compare this with earlier Last Suppers, we would see the way that the figures remained very separate from one another, and here that idea of the unified composition, which is so characteristic of the High Renaissance. But what I sense here more than anything is the divinity of Christ here in the center. His calm, the way that all of those perspective lines bring us toward him. 

It's interesting because that perspective that the artist is rendering is slightly at odds with the perspective as we see it from down here on the floor, that is we would need to be close to Christ's level to see this painting in a perspective, in the correct manner. And it's interesting; in a sense it elevates us as we look at this painting.

Now, keep in mind, we're not seeing this the way that people would've seen it in 1498. 

The painting is in terrible condition in part because Leonardo experimented with a combination of oil paint and tempera in an environment where fresco would be traditionally used, and the painting began to deteriorate soon after it was completed. 

Right, unlike a traditional fresco, which is painted on wet plaster, Leonardo painted on dry plaster and the paint never really adhered to the wall. So luckily for us, the Last Supper has been conserved.

And so in some ways, this is finding a way of creating a sense of the eternal, a sense of the perfect, but within the chaos that is the human experience. That's right, uniting the earthly and the divine.

We're in Saint Peter's Basilica, standing in front of Michelangelo's Pieta. 

I feel very lucky because on this rainy Monday morning, we're the only ones. 

And it actually looks quite small. 

It does. 

In relationship to the chapel that holds it, but also especially in relationship to Saint Peter's, which is so vast.

Of course, this sculpture was made for a cardinal, but then it was placed in the old Saint Peter's, which was significantly smaller than this one. And so it would have had a different relationship to the architecture. What I'm finding interesting is despite the fact that it's relatively small, and probably about 20 feet away from us, it's still a really intimate image. There really is this extraordinary relationship that Michelangelo has constructed between the body of the dead Christ and his mother, the Virgin Mary, who holds him on her lap. 

Mary looks very young and beautiful, but her body is, and her lap is sort of enlarged to carry the body of her dead son, with the realism that dead body, of its weight. 

One of the most beautiful passages, I think, of the sculpture is the way that she holds up his right arm, and pulls up that flesh a little bit. And you really feel first of all, that the marble is transformed by Michelangelo into flesh, but also the weight of that body, and through that weight, the loss of life that's so palpable for Mary. 

It's the complete lack of resistance that his body offers and the exertion that she has to extend in order to hold him. And that contrast makes for the viewer, I think, a very physical experience looking at the sculpture.

His body looks so much like the body of a real young man, the ribcage and the abdominal muscles. And yet it's also idealized in the way in which there's this beautiful turn of his body across her lap. And for Mary as well, there's this interesting contradiction in her sweetness and the beauty, but also the strength and the scale that's necessary for her to easily hold him. Look at how deeply carved that marble is. 

The drapery. 

This real love of the turn of the stone, that's creating this very vivid sense of alternation, really, of light and shadow, of complexity, of surface against the broad, pure surfaces of Christ's legs, of his torso, of his arm.

Mary tilts her head forward and looks down at him. His head is thrown back, so there's [INAUDIBLE] between those two necks for me. And his neck is exposed to us, incredibly vulnerable. 

Christ's foot hangs in midair. Mary, her left hand is open and pointing delicately forward, as if she still trying to comprehend his death. 

But I think there's also a way of presenting Christ's body to the viewers, saying this is the path to salvation. This is God's sacrifice for mankind, my sacrifice of my son that makes possible your redemption.

There is a kind of rhythm that points to that hand. The drape and the knee point up towards Christ's knees, which in turn create a kind of rhythmic bridge to her hand, and to that sense of wondering. This is very clearly an image that's meant to be contemplated. And the pain and the suffering that Christ has endured that—and Mary's enduring. That Mary is enduring is meant to be contemplated as a pathway. 

They're polishing the floor.

OK, let's move on.

We're in the very crowded and not very large room called the Stanza della Segnatura, that is not only dense with people, but it's dense with imagery. We're looking at frescoes by Raphael. 

Painted during the High Renaissance at the same time that Michelangelo was painting the Sistine Chapel ceiling just a few doors away. This room was originally a library, part of the papal apartments, that is the apartments where the Pope lived. In order to imagine what this room would have looked like at the beginning of the 16th Century, imagine away all of these people and imagine instead the lower walls lined with books. 

And also imagine quiet, which is hard to do here, and an environment of learning where you could look up at what Raphael painted here on the four walls, which are the four branches of human knowledge, philosophy, having to do with things of this world.

The philosophy at this time also meant what we now call the sciences. 

On the opposite wall, theology, having to do with issues relating to God and the divine. And on the two other walls, poetry and justice. So these four areas of human knowledge, symbolized by allegorical figures that we see on the ceiling, and it's so clear that a few doors away is Michelangelo, because Raphael is clearly looking at Michelangelo's figures on the ceiling of the Sistine Chapel, especially the prophets and the sybils.

What a moment in the High Renaissance, all commissioned thanks to Pope Julius II. And think about what it means for theology to be presented equally with human knowledge. It is this extraordinarily liberal moment in church history. When humanist classical learning can be united with the teachings of the church. In the center of the School of Athens, the fresco that represents philosophy, we have the two great philosophers from antiquity in the center: Plato and Aristotle, surrounded by other great thinkers and philosophers and mathematicians from antiquity.

Virtually every known great figure, but let's start with the two in the center. We can tell Plato from Aristotle because Plato is older. Plato was, in fact, Aristotle's teacher, but also because he holds one of his own books, the Timaeus. And Aristotle holds his book, the Ethics. Both of those books represent the contrasting philosophies of these two men. Plato was known for being interested in the ethereal, the theoretical, that which could not be seen, and, in fact, we see him pointing upward. This idea that the world of appearances is not the final truth, that there is a realm that is based on mathematics, on pure idea that is more true than the everyday world that we see.

Whereas Aristotle, his student, focused his attention on the observable, the actual, the physical. And you'll notice that his palm is down, and he seems to be saying, "No, no, no, let's pay attention to what is here." Right, to what we can see and observe in the world. 

In fact, if you look at the colors that each of the figures wear, they refer to this division. Plato wears red and purple, the purple referring to the ether, what we would call the air, the red to fire, neither of which have weight. Aristotle wears blue and brown, that is the colors of earth and water, which have gravity, which have weight. 

So the philosophers on either side of Plato and Aristotle continue this division. On the side of Plato, we see philosophers concerned with issues of the ideal. For example, on the lower left, we see Pythagoras, the great ancient mathematician who discovered laws of harmony in music, in mathematics. This idea that there is a reality that transcends the reality that we see. 

Compare that to the lower right where we see Euclid, the figure we associate with geometry. In fact, he seems to be drawing a geometric diagram for some very eager students. But he is interested in measure, that is the idea of the practical.

Euclid is modeled actually on a friend of Raphael's, and that's Bramante, the great architect asked by Pope Julius II to provide a new model for a new Saint Peter's. And in fact, appropriate to his reincarnation here as Euclid, Bramante's design for Saint Peter's was based on a perfect geometry of circles and squares and is really visible in the architecture that Raphael constructed for the School of Athens. Here we see an architecture that is very Bramantian, but also very ancient Roman. We have coffered barrel vaults, pilasters. This is a space that ennobles the figures that it contains. And we can see representations of classical sculpture in the niches on the left, that is on the platonic side. We see Apollo, the God of the Sun, the God of Music, the God of Poetry, things that would be appropriate to the platonic. And in turn on the right, we see Athena, the God of War and Wisdom, who presumably is involved in the more practical affairs of man.

 All of this seems to me to be a place that is the opposite of the medieval, where knowledge was something that was passed down by authority and one had to accept it. But here, on the walls of the papal apartments, we get this image of sharing knowledge and the history of the accumulation of knowledge all with figures who move beautifully, who in their bodies represent a gracefulness that is a reflection of their inner wisdom and knowledge.

You'll notice that Raphael has not placed any names within the painting. The only identifiers are perhaps the titles of the books that both Plato and Aristotle hold, and so we're meant to understand who these figures are through their movement, through their dress. Now, the artist has parted both groups to the left and the right so that the middle foreground is fairly empty. He does this, I think, for a couple of reasons. He wants the linear perspective at the bottom of the painting to balance the strong orthogonals at the top of the painting, and he wants to make way for the advancement of Plato and Aristotle as they walk down the stairs, but we also have two figures in the foreground in the middle.

We have Diogenes, and most interestingly, we have the ancient philosopher, Heraclitus, who seems to be writing and thinking quietly by himself. Most of the other figures in this painting are engaged with others, but not this man. He seems to be lost in his own thoughts. Well, and he is writing on a block of marble. And in fact, his features are those of the great artist Michelangelo, known for his rather lonely and brooding personality. Raphael has painted him here in the same pose as the prophet Isaiah on the Sistine ceiling, although Isaiah looks up, and here Michelangelo's Heraclitus decidedly looks down.

And so it's so interesting that Raphael is paying homage to Michelangelo the great artist here, personifying Heraclitus, the philosopher who believed that all things were always in flux. That figure of Heraclitus was actually added later. Raphael finished the fresco, added some wet plaster, and added in that figure. We should also note that Raphael included himself here. That's the young figure looking directly out at us in a black cap, and standing among some of the most important astronomers of all time. 

Including Ptolemy, who theorized about the movements of the planets. 

And Zoroaster, who's holding the celestial orb. 

We're so far here from the Medieval idea of the artist as a craftsman. Here the artist is considered an intellectual on par with some of the greatest thinkers in history, who can express these important ideas.

So we have dozens of figures here without any sense of stiffness or repetition. Raphael, like Leonardo in The Last Supper, divides the figures into groups. Each figure overlaps and moves easily between and amongst the others. My favorite two figures are the ones just behind Euclid, one leaning against the wall with his leg crossed over the other, who's hurrying and writing some notes. The other, leaning over and watching. 

There's a wonderful sense of intimacy there. 

I think it's a scene you could see walking along the hallway of any college or university. 

For all the free movement of the figures, the architecture itself is using a linear perspective in a rigorous way. You can follow the orthogonals either in the pavement or in the cornices as they recede back. 

So the illusion of space here is incredible.

Look at the way that the decoration of the Greek meander seems as if it goes back in space. What's interesting though is if this architecture is harking back to any ancient tradition, it's harking back to the Roman tradition, not to the Greeks, who would never use barrel vaults in this way. 

Nearby, Bramante, Raphael, Michelangelo could see the Baths of Caracalla or the Basilica of Manutius and Constantine. There was Roman architectural ruins all over the city that resembled what Raphael has painted here. It's so extraordinary that we're celebrating here, the Pantheon of great pagan thinkers. None of these men were Christians. Let's take a quick look at the frescoes that's opposite the School of Athens, known as the Dispute.

This fresco represents theology, the study of the divine. Figures here are divided between the heavenly and the earthly. Close to the top, we see God the Father in the dome of heaven. Below him, Christ in this marvelous full-body halo, or mandorla, and he's surrounded by the Virgin Mary on his right, and St. John the Baptist on his left. Just below, a dove against another gold disk, and this is the Holy Spirit, so all three together are the Trinity.

On either side of the dove are the four books of the gospels, Matthew, Mark, Luke and John, that tell the story of the life of Christ. On that wonderful bench of clouds sit prophets and saints. 

And we can actually recognize, for instance, Moses holding the 10 commandments. And then another circle below contains the host, or the bread that is miraculously the body of Christ during the Mass. 

And so the bread functions as a link between heaven and earth. We can see how separated heaven and earth are in this fresco, and how important that link is. 

The figures along the bottom are Popes and Bishops and Cardinals and members of various religious orders. The fathers of the church, we can make out a portrait of Dante, the great Medieval poet. We have a sense of the figures on the bottom of the fresco, coming to divine knowledge through the miracle of the host, and two figures on either end seem to be moving away from that divine knowledge. But there's efforts being made to turn them around, to bring them back.

So here, in the Stanza della Segnatura, a room that functioned as the library for Pope Julius II, a celebration of all aspects of human knowledge.