I have noticed that when all the lights are on, people tend to talk about what they are doing—their outer lives. Sitting round in candlelight or firelight, people start to talk about how they are feeling—their inner lives. They speak subjectively, they argue less, there are longer pauses. To sit alone without any electric light is curiously creative. I have my best ideas at dawn or at nightfall, but not if I switch on the lights—then I start thinking about projects, deadlines, demands, and the shadows and shapes of the house become objects, not suggestions, things that need to done, not a background to thought.