To exist as a book, the pages with their letters and spaces need a reader. We may think of books as unchanging material objects, but they only, as it were, happen when read; they have no absolute identity. And the nature of that reading—an experience extended over many hours, then mulled over for many more, for the book does not cease to happen the moment we turn the last page—will depend, to a large degree, on who the reader is. – New York Review of Books