By now, most of us have heard of the triune brain concept. Proposed by neuroscientist Paul D. MaClean, it provides a straightforward way of viewing the mind’s function and evolution.

MacLean divides the brain into three levels, which can roughly be described as cognitive, emotional, and instinctual. Because of its simplicity, the model has been criticized by some experts, but it has become quite popular just the same. I bring it up because it relates to my prior discussion about how I first learned to embrace emotions, but now feel it necessary to release them.

Every person’s development is unique, but there are common themes that repeat in the lives of many. In my case I started from the rather typical modern stance of deifying rational thought. Raised by a scientist, and then trained as one, I valued the mind’s ability to figure things out. It never occurred to me that such mentation could lead to problems. Thinking seemed perfectly reasonable.

The first fault line developed in that surety when I started to see my thoughts as obsessional. My difficulty never heightened to the level of diagnosable obsessive compulsive disorder (OCD), thank heaven, but a tendency toward repetitive and self-exacerbating negative thinking became obvious. At first, I worried about my future. When in college, fears about my grades kept me awake at night, even though I earned nearly all A’s. In medical school I obsessed about getting “the best” residency, even though there is no such thing. As my career fell apart in midlife I started panicking at the prospect of running out of money.

These obsessions were all different in substance, but identical in flavor. They combined with profound regrets about the past and fantasies about what might have been. This ‘woulda, coulda, shoulda‘ mentality turned into a kind of magical thinking: it almost felt like wishing hard enough would make things change.

This all looks clear to me now, but for many years my thinking kept me clouded by its apparent veracity. Cognitive Behavioral Therapy (CBT) helped me slowly break free. I began to challenge my faulty assumptions and unexamined logic. I learned to view my thoughts with a touch of skepticism.

In the triune brain, the most evolved and ‘human’ level is the neocortex. The source of logical thought, it is the single organ that most sets us apart from other animals. A magnificent tool in the right personality, it can become an instrument of torture if used badly. CBT taught me to rein in mental activities, and examine my thoughts more carefully. Granted, this amounts to using the cortex to steer the cortex, but it’s better than letting the mind run riot.

The interesting thing is that as I began to understand the characteristic mental pitfalls of (supposedly) rational thought, I began to see how the mind tricks us in many ways more subtle than scaring us with worry. It became clear that thought is perfectly capable of building convincing belief systems with only partial justification. Reason often blinds itself to counter arguments once this happens. Hence we see the myriad philosophical, metaphysical, and spiritual traditions that boast many passionate, and warring, adherents, but which cannot all be literally correct. In my own case, I’ve seen my beliefs change over time, repeatedly. These observations increased my doubt about the reliability of thinking as a guiding star for human life.

The next level down in the brain is the limbic system, the seat of emotion. This is a mammalian structure that we share with all warm, furry animals, and which no doubt accounts for how much easier it is to adore a puppy than a turtle. After working with CBT for several years, I started Acceptance and Commitment Therapy (ACT), which taught me to embrace my emotions. My ACT therapist encouraged me to sit still as emotions flowed through me. He also emphasized that feelings are transient and insubstantial. I learned that periods of deep sadness, which I might once have labelled ‘depression,’ can be tolerated or even appreciated as a sorrowful connection to the heart of life. I learned to rise into energized states, even exalted ones, while avoiding impulsive decisions or rash actions. I began to find a certain thrill in my ability to tolerate and even thrive in these intense states of mind. I felt more fully alive than ever before. I was fortunate around this time to meet Tom Wootton, who runs an organization called Bipolar Advantage in order to help others achieve exactly this kind of freedom.

But as I said in the last post, this surfing of emotional waves gradually grew a bit tiresome. If emotions are transient and insubstantial, why get swept away in the first place? Further, I began to understand more deeply how unreliable feelings can be. Sure, if you’re with someone you love, you feel authentic affection. But if you’re visiting an auto dealership and you feel a thrill at the thought of buying that shiny sports car, can you trust that fleeting excitement? If someone says something that seems hurtful and you feel angered, can you be sure you understood their meaning? Obviously, emotions are crude tools for evaluating reality.

They also are unpredictable. An experience that feels good at noon might feel awful in the evening. Think of the nice glow that comes with a first cup of coffee, and the jittery insomnia that comes with a seventh. Or consider how the excitement that might accompany an illicit love affair compares with the guilty consequences following consummation. Feelings are biological technologies that integrate huge spans of life and evolutionary history to provide nearly instantaneous feeling tones in charged situations. They’re quick but they’re unreliable.

So what’s left? If the vaulted neocortex generates confusion, and the fiery limbic system produces unreliable passions, where should we seek a center? Could it be that the lowly reptilian brain is actually the wisest?

The brainstem mediates the most basic functions of life: breathing, heart rate, hunger, and so on. As a result, it is simpler in its needs and demands. Whether to breathe or not is hardly open to debate or misinterpretation. And what do we do in mindfulness meditation? We pay attention to exactly these basic currents of life. Quite often, we simply tune into the breath.

Some Hindu spiritualists suggest the medulla oblongata, a quintessential reptilian structure, is the body’s entry point for cosmic energy. Maybe the lower centers are closer to whatever universal consciousness underlies life. Perhaps the neocortex and the limbic systems simply elaborate and complicate the basic awareness that comes with biological form.

You might argue that reptiles are too simple to be gurus. In many ways that may be the case. But life’s mysterious agency seems present at the lowest levels. Escherichia coli, the ubiquitous intestinal bacterium, has been investigated more completely than any other organism. It’s relative simplicity has long appealed to researchers, and its genome was the first to be elucidated. Most of its enzymes and receptors have been characterized. It is a simple creature, and one if its few volitional acts is the decision to either swim in a straight line (if it detects an increasing concentration of sugar, for instance) or to tumble in circles (a crude search strategy). This very simple choice remains mysterious. Despite the fact that so much is known about how the organism detects chemicals and how the detection alters internal processes, we still can’t predict the organism’s behavior or fully characterize it in mechanistic terms. Maybe scientists will eventually be able to describe E. coli as if it were a tiny robot, but it’s also possible that there is a minute consciousness at play that arises below the level of macromolecules.

If so, then this consciousness would be the deepest spiritual principle, and the one most grounded in fundamental reality. And yes, it might be more easily contacted by a lizard than by a deeply conflicted, overly passionate human.