The present determines where, in the object from the past, that object's fore-history and after-history diverge so as to circumscribe its nucleus. — Walter Benjamin

Consider two historical moments — nuclei, in Walter Benjamin's sense of the word — marking both the beginning and the end of the book as a media form.

The first is the publication of Stéphane Mallarmé's poem Un coup de dés Jamais N'Abolira Le HasardA Throw of the Dice will Never Abolish Chance (1897), imagined as a metonym for his multivolume, combinatorial Book, Le Livre. A radical experiment in design and typography, Un coup de dés privileges form over content &mdash or rather, form as content, such that blank spaces, typography and the material folds of the book, rather than semantics, generate what Mallarmé calls "prismatic subdivisions" of meaning on the page.

This unusual use of the book's architecture leaves the reader, rather than the writer, to cull and combine these scattered fragments of text through multimodal acts of association; thus the reader — Mallarmé prefers the word "operator," etymologically linked to "work," oeuvre, from the Latin opus^{1Maurice Blanchot, The Book to Come, trans. by Charlotte Mandell (Stanford, CA: Stanford University Press, 2003): 242.} — becomes an (inter)active participant in the poem's construction.