Von Dörnberg is conscious of the ambiguous relationships between modern concepts of dreaming and those of antiquity. On the one hand, the modern approach of in-depth psychologists rejects any testimony to transcendental reality and emphasises mental health aspects of dreaming whereas for the ancients what was real about the present or future was apprehended in dreaming. Yet the Aesculapian practice of incubation as a means of healing shows a more positive relationship between what is ancient and what is modern (pp. 16–18). A very real problem is that we have texts specifically on the nature of dreaming from Freud and Jung but no such texts from antiquity. Von Dörnberg therefore proposes to examine specific western texts with a number of questions in view. The metaphorical nature of images in dreams gives no direct indication of the author's view of the precise character of dreams, positive or negative. Only indirectly can it be ascertained whether the dream is creative or dangerous. Then there is the relationship between reports of dreams in the biblical and pagan traditions. Do the biblical dreams show that dreams are in themselves revelatory or only because they are part of the bible text? How do dreams reflect the author's historical context? Finally it will be necessary to reflect upon dreaming in the context of a theory of interpretation and significance of dreams for the authors in question (pp. 24–5). Tertullian, for example, describes dreams pejoratively as when Marcion dreams of two gods, or pagans that Christ has an ass's head, or Valentinus of Sophia's fall (p. 30). Biblical dreams Tertullian interpreted allegorically (p. 35), but likewise also pagan ones as when a lady who attended a tragic play dreamed of a linen robe and heard the tragedy being named with disapproval: these were metaphors of her death (p. 36). Tertullian's dream theory arises from his use of dreams to give evidence for his teaching on the soul (p. 65). Dörnberg throughout has been concerned with the distinction between a dream or a vision proclaimed by someone themselves and the report of a dream that someone else experienced. The latter have identifiable features exemplified in the Passion of Perpetua (pp. 82–3). The claim to a visio is indicative of the revelation quality of the dream that is reported, and there is a short account of the significance of reporting it. Similar features are noted for other martyrologies and in Cyprian through to Sulpicius Severus. Dörnberg's conclusion is that the features that he has established apply both in Christian and in pagan tradition in antiquity. The latter is exemplified by Cicero and Possidonius and reflected in Tertullian (p. 53), and by Homer, Virgil and Euripides in Ambrose (pp. 290–1). No one rules out dreaming as basically divine revelation (p. 355). Human souls as well as daemons are also the causes of dreams. But there are differences. In pagan accounts the gods can send false dreams but Christian writers see these as produced by heavenly powers in opposition to God (p. 356). The criteria of truth for Christians are the clarity of the dream, that it finds fulfilment, and that it is in agreement with Christian teaching (pp. 356–7). Von Dörnberg has provided a valuable study marked by erudition and comprehensiveness that is a significant contribution to research in this subject.