In his inaugural lecture, Professor Mayr-Harting presents a theme of religious history, namely angels, in a new light, seeking to counteract the sensationalism which is now becoming associated with the subject in many quarters. He first analyses the point of perceiving certain apparitions or experiences as angelic in generally socio-anthropological terms; he considers the hostility of angels - sometimes - towards men and how that hostility relates to the magical purposes of invoking angels. Finally, he argues that in the medieval West angels gradually lost their functions of intervention as social agents, and came to be considered more purely in their aspect of contemplators of God, and invisible, 'caelesticized', helpers of men.