Trustworthy modern doctors, after considering the observations supported by experiments, stated that sleep is an innate nature in humans, and they likened this innate nature to food, saying: A person can abstain from food or sleep for several days, a maximum of which does not exceed twenty, although among the poor of India there are those who continue for more than That, but they are a rare few who cannot be reckoned with. But the more man immerses himself in civilization, the more he creates forms of life that do not suit his nature, and they are the cause of his misery, the cause of his worries, and the path to his annihilation. One of these things that people are accustomed to in civilian life is that one stays up all night, then sleeps most of the day. The ancients replaced the light of candles and the moderns with the light of electricity, to dispel the darkness of the nights, and they began to spend their time in amusement and fooling around.