The darkness being a sort of self-reflectory confinement away from the light.
If the light is society, the darkness is the place you reflect on society, and your role in it. If the light is physical life, then the darkness is mental life. If the light is outer, then the darkness is inner.
And as all photo-takers know, good photographs are made through the perfect balance of light and dark. Do not let the age of faster and faster picture development blind from you the fact that the darkness, like the lightness, is a necessity.