Synesius' essay De insomniis ('On Dreams') - written soon after 400 AD by a man who was not only a highly educated Greek intellectual but also (in the last years of his life) a Christian bishop of the city of Ptolemais (Cyrenaica) - inquires into the ways and means by which a human being, while sleeping and dreaming, may make contact with higher spheres, and it does so in the light of a clearly recognizable Neo-Platonic concept of the soul and its salvation. Synesius' thoughts are thus an important contribution of Later Antiquity on topics - the place of man within the universe and his means of communication with higher powers - that not only were of high concern for his contemporaries, but still are today for religiously- and philosophically-minded people. Besides introduction and translation (with notes), several essays shed light on the work from the perspective of various disciplines.