 To counter this, the Roman Catholic Church authorised the production of many works of exorcism, the rituals of which were often very similar to those of demonic conjuration.Alongside these demonological works, grimoires on natural magic continued to be produced, including "Magia naturalis", written by Giambattista Della Porta (1535–1615).Iceland held magical traditions in regional work as well, most remarkably the Galdrabók where numerous symbols of mystic origin are dedicated to the practitioner.