Beautiful and revealing: The Three Pietàs of Michelangelo, at the Museo dell’Opera del Duomo, Florence, reviewed

The room is immersed in semi-darkness. Light filters down from above, glistening on polished marble as if it were flesh. This is the installation for Le Tre Pietà, a remarkable micro-exhibition that has just opened at the Museo dell’Opera del Duomo in Florence. It is low in quantity, containing just three works. But stratospherically high in quality, since it comprises Michelangelo’s three versions of the Pietà – that is, the Madonna mourning the dead Christ. He carved these over almost 70 years: one in his early twenties, the next in his seventies, the last in his eighties.

Admittedly, the first and the last are present only in a rather old-fashioned virtual form: high-quality plaster casts. And obviously, it would have been even more sensational if the original marbles of those works had been moved from Rome and Milan (something which is never, ever going to happen). But nonetheless, this display is both memorably beautiful and highly revealing.

None of these works is in the place for which Michelangelo intended it. But we know from various scraps of evidence that (just as you would expect of a great sculptor) he was highly sensitive to questions of placement and lighting. And this installation in Florence definitely comes much closer to the way his first Pietà would have originally been seen.

Nowadays, in St Peter’s, it is high up on an altar, behind protective glass, surrounded by baroque splendour. All of those factors are the opposite of what the artist anticipated. This Pietà was commissioned by a senior French clergyman for the Chapel of St Petronilla, a domed late Roman building that had become an annex of old St Peter’s (both structures were demolished within years of Michelangelo’s masterpiece being put in place).

There it would have been placed low-down so the extreme precision and finish of Christ’s body could have been contemplated from a few feet away, light seeping down on it from the rotunda above. This was why Michelangelo expended such effort, causing his friend and biographer Giorgio Vasari to exclaim that it would be impossible to find a nude with more beautiful limbs or ‘more detail in the muscles, veins and nerves’.

In the little Florentine exhibition you can contemplate all of that, but not properly in St Peter’s where you have to view the original from a distance, at the wrong angle, under strong electric illumination and surrounded by a scrum of other tourists waving their phones in an attempt to take a snap.

Famously Michelangelo took enormous trouble in selecting and supervising the quarrying of marble for this work from the mountains above Carrara. The effort paid off. The stone is superb. As you walk round the cast you can grasp what miraculous feats he achieved while carving it. There are voids like miniature caverns excavated in the Virgin’s billowing mantle, with membranes of marble around them not much thicker than cloth.

With stone you can do only what the material allows, which is one of the lessons of his second Pietà (of which the original is on display). Michelangelo began this around 1547, when he was 72. It was a commission from himself, intended to stand over his own tomb in a Roman church.

That never happened for two reasons. First, because Michelangelo’s corpse was stolen by patriotic Florentines and buried, against his wishes, in his native city. Second, because it seems that the block disintegrated under the blows of his chisel.

A recent restoration has revealed exactly why this happened. Michelangelo was attempting something extraordinarily difficult and ambitious: carving four interlinked figures from a single slab of mineral. But this time he’d got a terrible piece of marble to work on. According to Vasari, it was so ‘full of emery’ that ‘the chisel often struck sparks from it’. The restorers report that the stone is riddled with tiny fissures and flaws (some of these are visible).

There is a case for saying this isn’t a Pietà but a Deposition because Christ is being held not only by the Madonna and a female saint but also Nicodemus, a Pharisee who according to St John’s Gospel visited Jesus by night and later provided myrrh and aloes for his burial.

I’d prefer to say that this is a representation of Michelangelo’s personal faith – and also his stoical acceptance of mortality. The towering, hooded figure of Nicodemus is traditionally said to be a self-portrait, and that’s obviously correct. This pensive rough-hewn giant is the most impressive part of the work but, like most of the rest of the composition, it was never completed.

Apparently while Michelangelo was working on Christ’s body, the most highly finished part, it shattered (the figure is minus a left leg, presumably broken off). The fragments were pieced together and worked on further, with the great man’s agreement, by a pupil.

Then there is his final sculpture. Michelangelo laboured on this one, known as the Rondanini Pietà, almost until his death in 1564. He changed his mind about the initial group, and cut on and on, deeper into the block. When he died, he left a gnarled, whittled remnant, in which the frail figures of Christ and his mother seem to be supporting each other like survivors of a cataclysm. It’s shockingly different from the calm classicism of his early masterpiece.

Seeing these together, even two thirds in plaster, is a remarkable experience: a profound autobiography cut into three chunks of rock.