An observer of political and social affairs, a campaigner for Reform and sometimes an active participant, as in his visit to Ireland, Percy Bysshe Shelley understood a good deal about that aspect of the Spirit of the Age in England and Europe. He was a voracious reader in all fields and knew some of the famous writers and philosophers of the period. He had wide scientific interests and even when he was away in Italy kept in close touch with literary affairs in England. The huge bibliography of Shelley scholarship indicates the force of the spell that he has cast on readers and critics. The length of the gazetteer points to an essentially romantic aspect of Shelley, that of the wanderer continually in search of an ideal resting-place; and the list of his friends and acquaintances reminds one that, although he always emphasized his love of solitude.