Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker, PhD, is a masterful book by a neuroscientist working out of the University of California, Berkeley. Available at Amazon.

I read it a few months ago and could hardly put it down. The research is impeccable, the exactitude is without peer, and the writing is first class. Walker covers an enormous amount of material in this New York Times bestseller, and blends strong science with practical applications. After reading it I came away with a deeper appreciation of the importance of sleep, and how our lives literally depend on it.

There are so many insights in this book I don’t know where to start. It’s a treasure trove of facts and figures, laced with humor, childlike enthusiasm, and crisp writing. You’ll learn everything you need to know about caffeine, melatonin, sleep aids, jet lag, the role of sleep in health and disease, how and why we dream, the role of sleep in learning, sleep hygiene – you name it. Walker only allots three pages to lucid dreaming, but shares this remarkable comment: “It is possible that lucid dreamers represent the next iteration in Homo sapiens’ evolution.” Quite a statement from a scientist – and strong support for intrepid oneironauts.

One of the most compelling statements he makes has deep resonance with the wisdom traditions:

“Many of the explanations for why we sleep circle around a common, and perhaps erroneous, idea: sleep is the state we must enter in order to fix that which has been upset by wake. But what if we turned this argument on its head? What if sleep is so useful – so physiologically beneficial to every aspect of our being – that the real question is: Why did life ever bother to wake up? Considering how biologically damaging the state of wakefulness can often be, that is the true evolutionary puzzle here, not sleep. Adopt this perspective, and we can pose a very different theory: sleep was the first state of life on this planet, and it was from sleep that wakefulness emerged. [Emphasis added.] It may be a preposterous hypothesis, and one that nobody is taking seriously or exploring, but personally I do not think it to be entirely unreasonable.”

In Hinduism, sleep is referred to as causal consciousness, and is the foundational state from which both dreaming and waking consciousness emerged. It ‘causes’ all other states. Buddhism shares a similar view. When you read Walker’s book, his preposterous hypothesis becomes more and more tenable from a scientific perspective.

Why We Sleep is one of those rare books that bridges multiple disciplines and can change lives. It has helped me appreciate the elegance of sleep, and actually altered the way I approach my rest. While written as a popular book, it may have more science than some readers want. It may, indeed, put some readers to sleep. But as Walker himself playfully admits, nothing would make him happier. I savored the rigor and the constant reference to scientific research. This is what gives the book its punch. There is nothing wooly or New Agey about this tome. It is a clear-headed and no-nonsense look at one of the great mysteries of life – why do we sleep? Why is it so incredibly important?

Arianna Huffington’s 2016 book The Sleep Revolution: Transforming Your Life, One Night at a Time, (which I will review in a later post) sets the stage for Walker’s book, which takes this topic to the next level. Why We Sleep gets my highest recommendation.

Here is an interview with Terry Gross and Walker on her program “Fresh Air.”


And a talk at Google, that reveals Walker’s (the “Chuck Norris of sleep research”) wit and charm: