Volume I of this major critical edition of Shelley's prose - the first since the Julian Edition (1926-30) - provides authoritative texts of The Necessity of Atheism, the Irish pamphlets, the vegetarian essays, The Assassins, A Refutation of Deism, On Christianity, the `Hermit of Marlow' political writings, and several reviews. The texts, which are based on first editions and manuscripts, were all written between Shelley's last months in Oxford in 1811 and his departure for Italy in 1818: they preserve his original punctuation and spelling, and textual notes give copy-text variants, revisions, and deletions.

In addition, the Introduction supplies a full account of previous editions, and places the prose pieces in their political context; and the commentary pays particular attention to the problems of dating the manuscripts. The commentary also contains more detailed copy-text descriptions, more thorough accounts of provenance, and more information on sources and allusions, than any previous edition of the works.