Today, we are complex organisms that build skyscrapers, launch probes into space, and take selfies. But billions of years before us, into the tumultuous atmosphere of a young Earth, arrived bare elements from our sun and from nearby stars. These most basic molecules formed larger and more complex compounds, and those compounds, in a leap we have yet to reproduce, became cells.

Despite our cities and iphones, the sum of things we understand is so small relative to the total of things that we don’t. We may, as our knowledge expands, revisit the way we’ve defined life. But for now, something happened between inert compound and cell with metabolism that is beyond our scope of understanding. It’s possible that the progression from compound to organism wasn’t fundamentally different than those before it, just more complicated.

A similar thing has happened more recently. From some organisms possessing the qualities of life, mind emerged. Bacteria carry out their functions as programmed. Ants respond to environmental stimuli. Dolphins communicate with one another. Humans conduct experiments and record their findings for the next generations.

All of those organisms possess life, and most have a brain. But which have a mind?

As we develop more sophisticated technologies, it’s natural that science will focus on the emergence of consciousness. The mind is, after all, the instrument through which the universe has just begun to explore itself; the molecules that comprise our bones, muscles, and even our brains, were themselves created from the same materials that became rocks, trees, and planets.

Because we don’t grasp its origin, it’s difficult to stringently define life. It is similarly challenging to describe the mind. This may be to our benefit: if mind is natural progression of increasing biological complexity, and something that we consider distinct only because we don’t understand it well enough to categorize any better, an implication is that maybe a decision is not what we think it is.

Perhaps the choice I made this morning to scramble eggs rather than have cereal for breakfast was the output of a complex algorithm based on life experiences, manifested as organization of neural connections, coupled with data about my blood chemistry at the time.

Or maybe I did make a choice about breakfast, rather than weigh variables unconsciously and execute the decision they dictated. Did my mind make that choice? Is that the same as making the choice with my brain? When a long forgotten memory comes to the surface, has your mind recalled it? Or has your brain just fired a connection across a rarely used synapse, never strengthened through repetitive need? Is there a physical basis for that memory at all?

René Descartes, hugely important as both mathematician and philosopher, would argue that there’s not. Descartes believed that the corporeal brain was separate from the mind because we could see and touch it, and that the mind existed outside of the physical world.

But history has demonstrated that we can generate creative explanations for things we don’t fully understand. The study of medicine next to the infinitely complex human organism, for example: either a body of science exists which has to transcend present scientific method, or we have again reached a precipice where our instruments and methods are not sophisticated enough.

Are our brains “us”? Are “we” our bodies? Are those conditions exclusive? Descartes wrote that ‘the true substantial form of man’ was the soul, conceptually interchangeable with the mind. It seems inarguable that we are in fact more than the number or types of molecules comprising our bodies; every particle within us will be replaced many times over during our lives, bones will be broken down and rebuilt, the fat insulating the nerves in our brain will slough away a molecule at a time as new sheaths of myelin form around them. But throughout these processes, we never lose the quality of being a “self.”

Perhaps self is expression of the sum of connections between neurons in the brain, shaped over lifespan by experiences. The connectome, in this age, shouldn’t be an idea so difficult to accept.

When we experience something that leaves a lasting impression on us, it elicits a real physical change. If a driver is in an accident and from that point forward chooses to wear a seatbelt, it’s because his brainstem is urging his cortex to make choices that maximize his potential for survival and reproduction. Neural pathways are stimulated to propagate that message. He changed his mind about seatbelts, we could say. But truly, he changed his brain.

If a patient sustains a head injury, we can use powerful equipment to peer inside his skull and observe his brain itself. If he demonstrates memory loss, we can pinpoint the lesion responsible for the deficit. If he feels depressed, the cause may revolve around an imbalance of neurotransmitters, and while this becomes a complex cause-effect question, it also demonstrates that deficits of behavior can be inseparable from physical abnormalities.

But consider two patients with similar brain chemistry; one depressed and one normal. We might say things like one patient’s personality predisposed them to depression, while the imbalance affected the other patient to a lesser degree. Or that Patient X’s personality is the reason they complain of severe pain, while Patient Y is just a more resilient individual. These attributions happen all of the time because we don’t completely understand why symptoms are different if physical findings, even the microscopic ones, are the same. But these misunderstandings obfuscate the true explanation. We hesitate to define personality because it’s very complex, not because it’s categorically different from any other system in nature.

We often evaluate patients with a goal of pinpointing their physical maladies. Patients are relieved when we can tell them exactly which structure is causing their pain. They hope we can reduce the origin to its simplest unit. This model makes sense when we bring our cars to mechanics, but not when we bring our selves to providers.

Few patients respond readily to the idea that their chief deficit is misperception of pain. Deficient understanding of pain and its purpose may be a larger cause of their symptoms than a minor tissue injury. That shouldn’t be viewed as a problem or as something wrong with the patient, and it isn’t impossible to treat. What it means for clinical practice is that some patients will benefit as much from our educating them about pain as they will from any other treatment.

Many diseases are at least exacerbated by underlying psychological conditions, if not caused by them entirely. It will become clearer why pain is so highly variable between individuals. Consciousness is a fundamental question, but there is action to be taken in what we know about it already, even absent any comprehensive understanding; for example, that we can provide the stimulus for lasting neuroplastic changes by educating our patients about pain.