This book has done more to improve my understanding of pre-Enlightenment Western civilization, than, quite possibly, any one other work I can think of. The influence of the church on daily life, giving both fears (demons, Satan) and saviors - both of which were imminently more pressing when the only remedy for darkness was a candle whose poor light you could ill afford. (By the way, "burning the midnight oil" doesn't quite mean what you think it does.) The spread of disease, which was thought to be a result of the "bad night air", yet fear of it caused people to sleep, often all in one room, with the windows closed - thus practically ensuring that infection would spread to the whole family. One of the most surprising facts in the book is divided sleep, a phenomenon that the author maintains occurs in all primitive societies without electricity. People apparently become so well-rested that, going to bed near the fall of night, they have their "first sleep", awaken about midnight, lie awake (or find something to do) for 2-3 hours, then sleep some more. Ekrich points out that the body's hormones had completely adapted to this pattern. Thus, the aberration is our modern 6-8 hours at a stretch, something humans have not been doing that long really. This book is full of ideas like that. They are the kind of every day things that people think every one knows, so they are not written down, and, therefore, a bit of a challenge for the historian to unearth. (We all have these sort of "everybody knows that!" assumptions; just try coordinating a wedding. You'll soon find out both families have certain, largely unspoken, ideas of what a wedding should be.) Ekrich has written an enlightening book about a topic that has, amazingly, escaped scholarly light until now. A wonderful study of the dark half of our past.