It is not widely known that most people, before the advent of the Industrial Revolution around 1800, tended to go to sleep shortly after nightfall but then get up around midnight for several hours before going back to sleep until dawn. Modern lab experiments have been able to reproduce this ancient, two-sleep pattern. Furthermore, there is separate anecdotal evidence that a number of people currently practice divided sleep as a natural habit, without the prompting of an experiment. Some of these people, in turn, use their nighttime wakefulness period for creative thought, writing and problem solving. The divided sleep phenomenon fits in very well with the dualistic and holistic principles of East Asian philosophy. One should ideally integrate work, thought and sleep with the natural light cycle in order to maximize the potential for individual creativity over the course of a full day and night.

Sleep Before the Industrial Revolution

In August of 2013, while visiting Montreal, Canada, I briefly interviewed the manager of Lotus Buddhism store.  He had previously studied meditation under the world-famous Vietnamese Zen master, Thich Nhat Hanh, a widely read author and former Nobel Peace Prize nominee.  The manager stated that only 10 minutes of Zen meditation per day can, by clearing the mind, improve your concentration and thus enhance your focus for solving problems.  Clearing of the mind in meditation can also result in more intuitive, accurate and perceptive thoughts immediately afterwards; you may become more strongly intuitive.  All of this can therefore be an aid to coming up with new or creative ideas.

Nature, however, can provide another way to obtain some of the creative benefits of Zen meditation.  By nature, we mean the natural daily cycle of sunlight and darkness.  Prior to the Industrial Revolution, most people did not sleep straight through the night.  They slept over a longer span of time but within two distinct periods—“first sleep” and “second sleep.”  People would go to bed soon after sunset, sleep for about three to five hours, wake up for a two to three hour interlude, and then go back to sleep for another three to five hours until dawn.  The onset of first sleep was not substantially delayed by artificial—electric and electronic—lighting as it is nowadays.  Thus, before the 1800s, most people had the opportunity to enjoy a wakeful interlude within a total range of natural nighttime that averaged about 12 hours (A. Roger Ekirch, At Day’s Close:  Night in Times Past, 2006).

Modern experiments replicate the pre-industrial pattern of divided sleep

What is especially significant about Wehr’s experiments, …, is that the nighttime “…wakeful period, brain wave measurements indicated, resembled a state of meditation.”

Modern “photoperiodicity” experiments have been able to replicate the ancient two-sleep pattern.  Dr. Thomas Wehr of the National Institute of Mental Health performed a sleep experiment in the 1990s that he termed an exercise in “archaeology, or human paleobiology” (Clark Strand, The Washington Post, May 24, 2015).  A group of voluntary subjects resided for a month in an environment kept dark for 14 hours each day.  The initiation of sleep was marked by higher levels of melatonin hormone.  By week four of the study, the volunteers were sleeping an average of eight hours per night.  However, their sleep was not continuous; it took place across two distinct periods of time.  On average, the subjects would wake up after sleeping three to five hours, stay quietly awake for one to two hours, and then go back to sleep for another three to five hours (Thomas Wehr, Journal of Sleep Research, June 1992).

What is especially significant about Wehr’s experiments, from the standpoint of Zen and innovation, is that the nighttime “…wakeful period, brain wave measurements indicated, resembled a state of meditation” (Natalie Anger, The New York Times, March 14, 1995).  The subjects were not anxious.  Clark Strand states that, “The mind becomes calm and still, almost supple, and at the same time strangely more alert” (The Washington Post, May 24, 2015).  Ancient sutras record that the Buddha meditated during the middle of the night, between two and four a.m.  An English doctor living several hundred years ago wrote that contemplation and study were best done between “first sleep” and “second sleep” (A. Roger Ekirch, At Day’s Close:  Night in Times Past, 2006).

There is another, less obvious opportunity for productive thought due to divided sleep at night.  Part of sleep is known as the Rapid Eye Movement (REM) phase, so-named because of frequent eyelid fluttering observed by sleep researchers during this period.  REM “is the only phase of sleep during which the brain is as active as it is when we are fully conscious, and seems to offer our brains the best chance to come up with new ideas….  When we awaken [from REM sleep], are minds are often better able to make connections that were hidden in the jumble of information” (David K. Randall, The New York Times, September 22, 2012).  Making serendipitous connections is a large part of what goes into innovative thought in the first place, a point made by the late Steve Jobs.

Recent anecdotal evidence for the creative benefits of divided sleep

There is surprising anecdotal evidence that some people currently practice divided sleep at night as a natural habit, without the prompting of a lab experiment.  An online publication, SlumberWise (, has been collecting comments from these people since 2013.  Over 20 of the commenters stated that their middle-of-the-night session between first and second sleeps is productive in one or more ways.  Many of them are using this time to do writing for work, college courses, or books of fiction.  Several describe their work at night as “creative”, or “novel”, or getting their “best ideas.”  They often do “problem solving.”

Several describe their work at night as “creative”, or “novel”, or getting their “best ideas.”

Sample comments about the productivity and creativity of the two-sleep interlude include the following (, 2013-2016):

“I often awake mid-night…and write with a clear mind,…sorting out challenges that are easier to focus on when the mind is calm and distractions are minimal. I may write creatively at this time as well,…” (Alexander, January 2016).

“When I was working I found that the middle of the night was the best time to write letters or articles that had been ‘at the back of my mind’ for several days. Sometimes personal problems can surface and resolve themselves at this time. Also ‘forgotten’ memories can come back with great clarity” (Christine, September 2015).

“Whilst a doctoral student… These midnight sessions often resulted in my most productive study, writing, and thinking. …I never suffered from daytime fatigue” (Kim, January 2015).

“I found by accident the two-sleep method was a great help to me. I would use the waking interlude as my time to study and work on papers I had due. My best and most creative writing came out during this time period. I recommend it” (Karen, January 2014).

“I do this when I’m plodding through my first draft of a new book, …I noticed that  my word counts were much higher if I woke up and immediately began to write, …So I decided to  sleep twice and it really did increase my ability to focus and kept the writing easy and fluid” (Amalie, November 2013).

“Whenever I’ve gotten up after four or five hours sleep and feel my body is not going back to  sleep, I know  that this  is  a creative time for me. A project that I’ve been working on suddenly becomes clear and the writing flows easily.  And yes, then I can go back to sleep” (Connie, September 2013).

“I am a two phase sleeper. …being relaxed and partially awake has helped me think through many solutions to a variety of novel problems in the research I do” (Arthole, August 2013).

“I am a two phase sleeper. …being relaxed and partially awake has helped me think through many solutions to a variety of novel problems in the research I do.”

Many of these SlumberWise commenters have been doing two sleeps per night for years and years, since childhood or college. Clearly, divided sleep in the 21st century is not purely an experimental phenomenon, and it does not appear to be solely an effect of genetic inheritance.

Some people should be able to replicate a bimodal or two-sleep habit on their own. There are a number of ways to assist this process. The most important is appropriate lighting.  Avoid harsh, melatonin-reducing “blue” light from TVs, computers and smart phones during the wakeful phase between the two sleeps (and also right before the first sleep). Instead, use soft LED lighting, preferably with a dimmer switch, in yellow, red or orange colors. Use heavy curtains to keep out bright lunar or other outdoor light sources. Some wear an eye mask to get back to sleep. Going further, it is possible to coat your glasses with a protective substance, from Cryzal, that filters out blue light. There are even programs for computers (e.g., “f-lux”) that change the lighting tones on the screen (, 2013-2015).          

Conclusion:  Yin-Yang representation of holistic work and sleep pattern

In Zen and Daoist philosophy, the opposing but complementary “forces” of yin and yang are conventionally represented through a circle bisected by a wavy, reverse S-line.   This is the well-known taijitu symbol (see below).  The two halves of the circle contain contrasting colors, usually white and black.  Each half of the circle looks like a “head” tapering off to an inwardly curving “tail”.  Also, each head half of the circle includes a small, circular “seed” of the opposing color.  This circle and seed pattern is meant to represent the holistic and complementary character of the yin-yang paired opposites.

In the typical North American’s daily routine, all job work is done in the daytime, and all sleep is done in one stretch at night.  In yin-yang terms, the wavy halves of the taijitu circle are incomplete—they lack the contrasting “seeds”.  A more natural balance between work, thinking and sleep is recommended here.  There should ideally be two sleep periods at night separated by a potentially creative wakeful interlude.  Also, the usual daytime work period could include a quiet break—either mindfulness meditation/relaxation or an afternoon “siesta”, popular in much of Europe and Latin America.

This naturalistic approach to work and sleep completes the yin-yang taijitu.  The nighttime sleep phase contains a seed of productive wakefulness; the daytime work phase includes a seed of rest or meditation.  An organically balanced daily cycle is simply a modern manifestation of the ancient Chinese Dao, or “way of nature.”

Is all of this worth a try?  Dim the lights.  Sleep on it!

By Gary W. Davis

About the Author

Gary Davis is an economist working in Washington, D. C. He has published articles on Eastern philosophy for business innovation in several management journals, including Innovation Management. In 2009-2010, he published an article, “Contexts for Innovation,” in magazines in both the U. S. and Malaysia. The article recommends a synthesis of Eastern and Western strategies for business teams. He has studied innovation processes in connection with a position as research team leader. Gary Davis has presented economics papers at seminars and national conferences (e.g., of the Southern Economics Association and Society of Government Economists). He also gave a presentation on innovation to a U. S. Federal government seminar. He holds Master’s degrees in Economics and Public Administration and a Doctorate in Public Administration from George Mason University, Virginia.