There is a kind of reading available only to those who return. The first encounter with a great novel, however attentive, (0) SKIMS the surface of its architecture; it is the rereading that one down into the substrata, where motifs one had mistaken for ornament reveal themselves as beams. The reader discovers, with something between delight and chagrin, that the book has the same while she has changed, and that much of what strikes her now as the author's subtlety was in fact her own earlier inattention for his silence. This peculiar arithmetic — the stability of the text against the flux of the reader — is what makes rereading a form of autobiography by other means. One returns to a novel at thirty and meets a version of oneself at twenty, in the margins, arguing with passages one no longer finds contentious. Rereading is therefore less a matter of exhausting a book than of permitting it to one's own successive selves, each in its turn. The shelves of a serious reader are, in this light, a kind of register of everything she has been.