You have seen the image hundreds of times. It has been copied and parodied relentlessly for over five hundred years. It shows Jesus at the center of a dining table, flanked by six disciples on either side. Everyone knows _The Last Supper_, but few know as much about it as Leo Steinberg, who has looked and written and thought about it for thirty years. The result of these decades of concentration are poured out in _Leonardo's Incessant Last Supper_ (Zone Books), as close an examination of a painting as you will ever find. The book is not about the painting's history, its decay, or its restoration; it is, in astonishing detail, about the looks of the picture itself and a demonstration of how it continues to be an "incessant" font of thought and speculation as to its meaning. Steinberg's big book is wonderfully well illustrated, with details from the original, a generous gatefold to show it in its current restored state, pictures of how it looks within the refectory of Santa Maria delle Grazie, how Rubens, Van Dyck, Rembrandt, and a host of others copied the painting (and how they left out significant parts, and what the omissions mean), and plenty of diagrams to show such things as the lines of perspective and the effects of matrices and diagonals on Leonardo's meticulously planned original.
Steinberg has chapters on the disciples, on feet and hands, on the disciples, and more. The main figure, that of Jesus, bears, of course, the closest examination, and Steinberg details the history of thought about it, with writers weighing in on the meaning of the pose and the timing within the Gospel story of the scene depicted. Over and over, Steinberg shows that to seek a meaning and a timing is in vain. Leonardo has deliberately engineered his work so that any explanation involving a single meaning will be an oversimplification. Jesus's right hand is downturned in a gesture of apprehension. It is close to a mirror image of the left hand of Judas as they reach simultaneously towards the dish by which Jesus will designate his betrayer. It is also gesturing towards the wine, so that it marks the institution of the Eucharist; after reading Steinberg's work, the idea that Leonardo drew these two separate parts of the story together and told them as one is only one of the multiple meanings that seem natural on further reflection. Jesus's left hand is upturned, gesturing toward the bread. It also underlies the portentous hand of Thomas, hovering directly above it. Thomas's hand has an index finger pointing up, continuing the upturn theme of Jesus's left, and indicating, of course, higher things. It is Thomas's index finger that would soon be feeling around for confirmation of Jesus's wounds.
To read this book is to appreciate a hundred telling details in the painting which one did not notice before, and consequently to admire Leonardo's genius anew. It is also to admire the fruition of the decades of Steinberg's close study. His readers may feel a sense of humility that there was so much to see that had previously escaped them, but his witty, sure, and genial expertise will welcome them into seeing _The Last Supper_ with new vision.