Playing off a short story by H. G. Wells, Simone Weil drew an analogy to a land of blind people in which scientists could devise a complete system of physics leaving out the concept of light. Weightless, pressureless, undetectable by the senses -- why believe in light? To the blind, it need not exist. Occasionally, however, questions might arise among the blind. What makes plants grow upwards, defying the law of gravity? What ripens fruits and seeds? What warms the night into day? Light in a country of the blind, says Weil, parallels the role of God on earth. Some of us sense traces of the supernatural, yet how do we prove it to people who can't detect it?