In the often-tense period before Christmas many parents are especially likely to tell their children that if they don't go to sleep promptly Santa Claus will not bring them any presents. Or that he will bring them only a lump of coal. Part of their rationale for telling this lie is that they want their children to go to sleep at the same time every night for their own good. I have very little doubt that a coercive parent could produce a whole line of experts recommending that a child should always sleep eight hours a night and maintain a rigorous routine when it comes to sleep. Nevertheless, I think this idea is a bit of a red herring – and here's why.
In reality, a person's interests are rarely best served by sticking absolutely rigorously to a certain routine – even when it comes to sleep. Instead we ought to learn how to make the decision of when to sleep based on the costs and benefits of that decision. Here's a small example: recently I was reading a book (Downfall, about the American decision to use atom bombs at the end of World War II). One night while I was reading it I started to feel very tired, and I was still thirty pages from the end. I had to make a choice. One the one hand, if I went to bed and slept I would feel less tired. On the other, it wouldn't take me long to read the last thirty pages, and I could see some benefits of doing so. Obviously, I was interested in what was on those pages. If I stopped I would have to pick up the threads of what the author was saying at the point where I stopped reading, and that would take some time and effort. So I stayed up and read the last thirty pages and then started a new book in the morning. Regular sleep is not infinitely valuable and sticking to a routine has a price. I am not saying that sticking to a routine is always wrong: sometimes it is best. But a person cannot rationally decide whether it is the right thing in a particular situation by applying a mechanical criterion in favour of a sleep routine.
There is a further problem with the dogma of regular sleep. Sometimes, despite his best efforts to the contrary, a person can't get to sleep. Perhaps the room he is trying to sleep in is too warm or too cold. Perhaps he is anxious about his job or his finances. Maybe he is sleeping in a hotel and finds the mattresses the hotel uses uncomfortable because they are too hard or too soft. So should he lie in bed when he thinks trying to get to sleep is going to be fruitless, or get up and do something? Sometimes he should persist and sometimes he should get up, and there isn't a mechanical way to decide this.
Deciding when to go to sleep is a special case of the sorts of decisions people have to make all the time about how to manage their lives. Parents should not impose their particular vision of when it is and is not appropriate to sleep on their children. Instead they should help their child to explore the costs and benefits of different policies on sleep so that he will be able to make rational decisions about sleep instead of adopting a dogmatic and self-denying attitude towards it.