Is a book the same book--or a reader the same reader--the second time around? The seventeen authors in this witty and poignant collection of essays all agree on the answer: Never. The editor of "Rereadings "is Anne Fadiman, and readers of her bestselling book "Ex Libris "will find this volume especially satisfying. Her chosen authors include Sven Birkerts, Allegra Goodman, Vivian Gornick, Patricia Hampl, Phillip Lopate, and Luc Sante; the objects of their literary affections range from "Pride and Prejudice "to "Sue Barton, Student Nurse," These essays are not conventional literary criticism; they are about relationships. "Rereadings "reveals at least as much about the reader as about the book: each is a miniature memoir that focuses on that most interesting of topics, the protean nature of love. And as every bibliophile knows, no love is more life-changing than the love of a book.