All headnotes are new or updated, and many footnotes have been added, replaced, or revised. Criticism reflects the recent renaissance in Shelley studies, the greatest renaissance since 1870-92. All twenty-three essays are new to the Second Edition; among them are the work of Harold Bloom, Stuart Curran, Annette Wheeler Cafarelli, Michael Ferber, James Chandler, and Susan J. Wolfson. A Chronology, an updated Selected Bibliography, and an Index of Titles and First Lines are included.