We're all intimately familiar with the 24-hour cycle of being awake and sleeping — and then being awake again—and then sleeping. This cycle is so commonplace that we often take it for granted, as part and parcel of what it means to be a human being.

This changes, of course, if we have trouble sleeping or problems staying awake during the day. When the waking and sleeping cycle is out of whack, our physical and psychological health tends to suffer, leading us to pay closer attention to it.

If we're tinkering with our sleep cycle, it's generally to try to fall asleep more efficiently or sleep more deeply. Alternatively, we may be aspiring to be more energetic and alert during our waking hours. In either case, it's the toggling back-and-forth between being awake and being asleep that is the overarching framework.

Sleep In The Yoga Tradition: The Four States

The yoga tradition offers another exciting way of viewing the sleep cycle. In yoga philosophy, rest has a fourfold period, which includes:

1. The Waking State
2. The Dream State
3. Deep Sleep
4. Meditation (Turiya)

The first three of these — waking, dreaming, and deep sleep — are considered to be states of consciousness that come and go. The fourth — true meditation or Turiya — is understood to be the unchanging "container" within which waking, dreaming, and deep-sleep happens.

While everyone experiences their waking world, and most people have some recollection of dreams, the deep-sleep period, as well as the fourth state of meditation, can be a bit more challenging to experience knowingly.

Nevertheless, there are some excellent reasons to become familiar with all four of these aspects of our 24-hour cycle. While formally practicing yoga or meditation is one way to support this new awareness, you can also explore it on your own. And one way of entering into such contemplation is to become aware of the overlap and similarities between dreaming and the waking state.

Exploring The Overlap and Gaps Between Sleeping and Waking 

We've all experienced varying degrees of drowsiness in the waking state: feeling dull or sleepy, for instance.

And we've all experienced the dream-like states of imagination — of mental fantasy, planning, or memory — that have a very dream-like quality even though we're technically awake.

And though we don't remember deep sleep, our sense of being "well-rested" when we wake up in the morning, has a lot to do with entering this deep-sleep state at night.

Most of us recall at least some of our dreams — whether pleasant, scary, neutral, or occasionally providing symbolic answers to waking-world questions. We may even keep a journal devoted entirely to recording our dreams. And the fact that we can remember our dreams means that, at least to some extent, they have been transferred into our waking-world experience.

Dreams, Imagination, and Thought-Experiments

Einstein's use of imagination and thought-experiments in developing his famous Theory of Relativity is well-known. And a plethora of other artists, musicians, mathematicians, and scientists have received creative inspiration from their dreams.

For instance, describing one of his many insightful dreams, the brilliant Indian mathematician Ramanujan said:

"While asleep I had an unusual experience. There was a red screen formed by flowing blood as it were. I was observing it. Suddenly a hand began to write on the screen. I became all attention. That hand wrote a number of results in elliptic integrals. They stuck to my mind. As soon as I woke up, I committed them to writing..."

The point is that the boundaries between waking-state experience and dream-state experience can be somewhat blurry. Even though scientists have identified brainwave patterns that are generally associated with the dream-state, deep sleep, and the waking-state — when we consider our direct experience, the categories are not necessarily as clear-cut.

The Fleeting Nature Of Dream and Waking-State Phenomena

What the experiences in all three of these categories have in common is that they are transient and impermanent: they come and go. For instance:

• In our waking-state, we may taste a delicious peach. Its texture, flavor, and aroma last for a few minutes but then are gone.
• In our dream-state, we may encounter a scary monster. Its noxious scent and blood-curdling roar will continue for a while, but then the imagery ceases — either because we've moved onto another dream, or we've woken up.
• And while the experience of deep-sleep is deeply nourishing and healing, we tend to lose our connection with that nourishment the moment that we wake up in the morning, or shortly after that.

So the things that we experience during our dreams, as well as our waking life, are all equally ephemeral — equally dreamlike, we might say, in that they come and go continuously.

Is there any aspect of our experience that remains constant and unchanging? That is the question that the yoga tradition poses, and then answers with a resounding yes!

Turiya: Our True Self Beyond Waking, Dreaming and Deep Sleep

It is the fourth state — called Turiya in Sanskrit — that, according to the Yoga tradition, remains constant throughout all of the changes of the dream-world and waking-world. And the reason that deep sleep is so nourishing is that it acts as a portal to this unchanging fourth state, Turiya.

In his essay, The Four States of Waking, Dream, Deep Sleep and Turiya, David Frawley explores the four states in terms of their centrality to Yoga and meditation. Here's how he describes this connection between deep sleep and meditation/Turiya — which he refers to as eternal consciousness:

"Without adequate deep sleep, physical and psychological immunity, resilience and harmony break down, leading to an eventual collapse of the entire organism. What is the nature of this healing power of deep sleep? According to Yoga and Vedanta it is because we return to the source of our being, the core eternal consciousness within us, which is not limited by external bodily factors."

While deep sleep tends to be characterized by darkness and forgetfulness — most of us experience it as something like a blank void — it is the "place" that we taste the self-aware state that is our true identity, the core of our being.

This True Self that we contact in a deep sleep is a continuous state of immutable awareness. It is the witness of all of the events of our waking-world as well as our dream-worlds. It is infinite, eternal, and unchanging. It is the aware, awake presence that is perceiving and understanding these words, right now!

What the Yoga traditions teach is that becoming knowingly aware of this "fourth state" — Turiya or natural meditation — is the key to lasting peace and happiness.

If we can learn to abide in our true identity as pure awareness, then we are no longer bothered by the coming and going of waking-world or dream-world phenomena. While we still can enjoy our waking and dreaming experiences, we no longer depend upon them for our ultimate happiness. And this is true freedom.

How To Enhance Access To Meditation/Turiya

Yogis claim that until we realize the essence of our being — i.e., meditation/Turiya — we remain "asleep" even during the waking state.

With a devoted Yoga or meditation practice, we can cultivate a type of focused attention, concentration, and intuition that allows us to experience the "fourth" state of Turiya directly. And in doing so, we touch our eternal essence — which is unlimited by time or space, birth or death.

And then we can go about our lives, identified with this ever-aware and wakeful witness that remains free in the face of the changing appearances of the waking and dreaming worlds; and free from the ever-shifting thoughts and images of the mind.

Tips For Exploring The Four States:

• Use yoga and meditation to inquire into waking, dream, deep sleep, and beyond. Be curious about these aspects of your experience, moment by moment, twenty-four hours per day.
• Meditate for 15-20 minutes right before going to sleep, as a way of turning dream and deep sleep into a form of meditation.
• Approach going to sleep at night as a potential gateway to a profound realization of your most essential identity, which lies beyond the transient illusions of the world.
• Understand Turiya not as a separate state—but rather as the unchanging reality that pervades waking, dreaming, and deep sleep.

Sweet Dreams!

Exploring the four states of waking, dreaming, deep sleep, and meditation can be quite profound.

And remember, also, that a high-quality mattress and comfortable bedding will naturally enhance your dreaming and deep sleep experience.