Book excerpt: Light and darkness shape our perception of the world. This is true in a literal sense, but also metaphorically: in theology, philosophy, literature and the arts the light of day signifies life, safety, knowledge and all that is good, while the darkness of the night suggests death, danger, ignorance and evil. A closer inspection, however, reveals that things are not quite so clear cut and that light and darkness cannot be understood as simple binary opposites. On a biological level, for example, daylight and darkness are inseparable factors in the calibration of our circadian rhythms, and a lack of periodical darkness appears to be as contrary to health as a lack of exposure to sunlight. On a cultural level, too, night and darkness are far from being universally condemnable: in fiction, drama and poetry the darkness of the night allows not only nightmares but also dreams, it allows criminals to ply their trade and allows lovers to meet, it allows the pursuit of pleasure as well as deep thought, it allows metamorphoses, transformations and transgressions unthinkable in the light of day. But night is not merely darkness. The night gains significance as an alternative space, as an ‘other of the day’, only when it is at least partially illuminated. The volume examines the interconnection of night, darkness and nocturnal illumination across a broad range of literary texts. The individual essays examine historically specific light conditions in literature, tracing the symbolic and metaphoric content of darkness and illumination and the attitudes towards them.