This book advertises itself as a simple republication of the book-length essay, “Leonardo’s Last Supper,” that first appeared in the Art Quarterly in 1973 (Art Quarterly 36, no. 4 [1973]: 297–410). Steinberg interlards the introduction with italicized passages; the first mentions Jonathan Crary’s invitation, in 1997, to republish the essay as a book, and another begins: “At this point, I might as well reprint the rest” (13). But the book is far from a reprint: The majority of paragraphs are revised, there are wholly new pages, the notes altered and the chapters renumbered and rearranged, and the catalogue of copies is now a small monograph in its own right. I lost count of Steinberg’s emendations midway through the second chapter, at which point I had noted 120 changes. Steinberg has apparently kept an assiduous record of the literature occasioned by this essay since 1973, yet the sad fact is that it has been often mentioned but little discussed. (The exception is Georg Eichholz’s Das Abendmahl Leonardo da Vincis [Munich: Scaneg, 1998]; see Steinberg, 168 n. 9.) Even the essay’s (and the book’s) principal opening claim-that Leonardo’s painting, in Steinberg’s words, ambiguates between the Last Supper and the Institution of the...