What is the opposite of 1? You might think -1, and -1 x -1 = 1, which is a bit like saying the opposite of opposite is the same. However, in boolean logic, on is represented by 1 and off by 0. That sort of makes sense too, because the absence of light is darkness. However you'd think the opposite of 0 is ꝏ. Total darkness is hard to achieve, white total light would mean cramming the room full of photons, so there must be a level below which it is considered dark (0) and above which it is considered light (1). What does Bertrand Russell have to say about it?