Hardy's editing of Berlin's essays made Berlin's most important work widely available. In 1990 Hardy abandoned his career in publishing to work full-time on Berlin's unpublished essays, lectures, and correspondence. He has (co-)edited eighteen volumes of Berlin's writings (plus new editions of thirteen of these volumes), as well as a four-volume edition of Berlin's letters, and two books and a pamphlet about Berlin. In 2018 he published a memoir of his work with and on Berlin. Reviewing the book for 'Best Books of 2018' in the "Guardian", John Banville wrote: ‘Henry Hardy has self-effacingly devoted the larger part of his professional career to the editing, promoting and celebrating of the work of Isaiah Berlin. "In Search of Isaiah Berlin: A Literary Adventure" (I.B.Tauris) looks back over his long labours of love with fondness, a fine dry wit and a light salting of justified irritation at those entrusted with Berlin’s posthumous affairs. The second part consists of Hardy’s own philosophical response to Berlin’s theories on matters such as plurality, religious belief and our shared human nature. A wonderful book on a wonderful subject.’