The psychologist Richard O'Connor writes in his recent book Rewire that: "The truth is that feelings like happiness, satisfaction, and fulfillment are not the normal resting state of the human mind (mild anxiety is), and we have to make a deliberate effort if we want to achieve these states."

I don't doubt this assessment. But the curious phrase here is "resting state." How can a mind (or brain) be at rest and yet anxious? Doesn't anxiety denote, or is associated with, activity in the nervous system, corresponding with subjective states (mind) of agitation, disturbance, and the emotional states of worry and fear?

I think here the author is drawing an analogy with electrical current, akin to neurons that electrically fire on and off, i.e. action and potentiation, in response to chemical triggers. In electro-dynamics, to be in a "resting state" simply means to not yet be activated, but constantly ready to be. So a neuron (or mind-state) at "rest" is the normal state that is ready (i.e. wired) to fire. It's not what I'd consider a relaxed state akin to muscles, that is, the opposite of tight, tense, contracted, and stiff, or subjectively, the opposite of anxious. 

A resting state of mind, here, further denotes only one particular state of consciousness - the awake and alert state. This is the mind in survival mode. As the body-mind is inextricably bound to its environment, we can see that patterns of movement, behavior, and changes in states of energy in the environment (stimulus) cause activity and movement in organisms (response). The body and brain respond mechanically, chemically, and electrically to their environment (really, more changes in states of energy, i.e. patterns of movement).

Content-wise, the mind while awake normally scans the environment for potential or actual threats, focuses on problems and solutions, attemps to understand, organize, and conceptualize patterns of sensation and perception, to predict and control its surroundings, and it desires.

The interesting thing is that the brain-mind does this even when there are no threats in the environment and no problems in the present-moment. It doesn't often feel placid or totally at ease even if there are no immediate stressors. That it continues to be activated when there are none of the typical stimuli in the environment it has evolved to attune to characterizes much of the human condition. Even in an ideally controlled environment, the mind is indeed often mildly anxious and/or bored (boredom itself is a stressor; see this episode of Mind Field for an interesting investigation of lack of stimulation: https://www.youtube.com/watch?v=iqKdEhx-dD4).

There are more relaxed states of mind, both while awake and asleep. During dreaming periods of sleep, one can be more or less relaxed (and emotions, experienced even more directly than during most of the waking hours, due to heightened activation of subcortical regions of the brain, can be intense and often unpleasant). But the most truly relaxed, undisturbed, state is deep dreamless sleep. The body and consciousness are truly both relaxed and at rest in deep dreamless sleep. The body repairs itself and heals during these periods. Not enough time in this state, or in REM dreaming sleep, weakens our immune system and impairs brain health, emotional wellbeing, and cognitive performance during the day.

However, all of our important, meaningful, and intentional activity happens while awake (not counting lucid or pellucid sleep). And the quality of the mind during this phase of consciousness reflects, and is reflected by, the quality of our overall lives.

Different systems of Indian Yoga (including heterodox systems like Buddha Dharma and Jainism), not to mention other Asian systems such as Taoism, have means of training the mind, and show us how the mind, even during the waking phase of consciousness, can get out of the rut of perpetual anxiety and other unpleasant states (e.g. anger, jealousy, shame, obsession, etc.) Contemplation works on not just the delibilitating forms of anxiety that clinicians and psychiatrists are trained to relieve, but even the normal, every day type that plagues most of us.

This seems like an extraordinary claim, and as Carl Sagan once said, extraordinary claims require extraordinary evidence. I don't know if the evidence is "extraordinary," but there certainly is evidence from medical and psychological research that meditation (or spiritual contemplation) helps with stress. And traditionally, the evidence, especially in Yoga and Buddhism, comes from a progressive system of inner (even outer) confirmation by the practicing yogi.

Yoga postulates that there is a fourth state of consciousness (called Turiya) that is like deep dreamless sleep, except that the person is entirely awake. In this state, one of aware, but there are no objects, so to speak, to be aware of. The normal frames of reference that exist in spacetime cease to apply.

That is a big claim, and yet some practicing meditators have claimed to have experienced a timeless, pure presence while awake (it may be exactly the same during deep dreamless sleep, yet, we can't seem to form a memory of it, or what it's like, while awake, whereas mystics and contemplatives do seem to remember consciously slipping into it).

Let's suppose such a state of mind is even possible (it may not be, admittedly). This would be a brain with very little activity, or perhaps less erratic activity. This would be a mind that is not only calm, but clear, able to reflect like a mirror. The mind does not have to do anything to be aware, awareness is its natural state.

In this mirror-state, reflection and that which is reflected are one. Everything is seen objectively (wisdom), and there is no agitation or aggression. It may be passive (the word passive related to pacific, meaning "peaceful," and indeed this would be an ultimate peace), though there is the activity of reflecting. Yet there is no conflict between reflected and reflector. There is no obstruction or any obstacle preventing reflection.

Subjectively, such a state is free of emotional turmoil, and there is no desire for peace or happiness when that is already experienced as the default state.

That, to me, would be true rest. And we can each get a taste of this when we notice the space between in-breath and out-breath when the body is still, and between the passing of one thought and the arising of another.