For many years my wife and I have spent our summers on an island in Maine. It’s a small island, only about 30 acres in size, and there are no bridges or ferries connecting it to the mainland.  Consequently, each of the families who live on the island has their own transportation.

One night in the wee hours, I was coming back to the island in my boat, alone on the ocean, and I decided to turn off the engine and running lights. It was a clear, moonless night, and the sky bristled with stars.  Then I lay down in the boat and looked up. After a few minutes, my world dissolved into that star littered sky. The boat disappeared. My body disappeared. And I found myself falling into infinity. I felt an overwhelming connection to the stars, as if I were part of them. I felt a merging with something far larger than myself. And the vast extent of time, from the far distant past to the far distant future, seemed compressed to a dot. After a while, I sat up and started the engine again. I had no idea how long I’d been lying there looking up. What had happened to me?

I’ve worked as a physicist for many years, and I’ve always held a purely scientific view of the world. By that, I mean that the universe is made of material stuff, and that the cosmos is governed by a small number of fundamental forces and laws. Yet at that moment in the boat, if you had connected my brain to a giant computer and gotten a readout of the electrical and chemical activity of every neuron in my brain, all that data wouldn’t come close to capturing my experience. While I believe that all of our human experiences are rooted in the material brain, many of them cannot be reduced to 0s and 1s.

I call myself a spiritual materialist. By materialism, I don’t mean the worship of new cars and nice clothes, but the more literal notion that the world is made of atoms and molecules, and nothing more. At the same time, I acknowledge and embrace the fact that we human beings are capable of such “spiritual” experiences as feeling a part of things larger than ourselves, feeling connected to nature, the appreciation of beauty, awe. Even with the caveat that we cannot yet fill in all the blanks leading from the brain to complex human experiences, I suggest that science, and the world view of science, is completely compatible with spiritual experiences, as I have defined them.

Alchemical illustration in the "Basilica Philosophica" section of Johann Daniel Mylius' Opus Medico-Chymicum, (page 273, 1618)

Many people believe these experiences are the result of an omniscient and purposeful Being. I respect such beliefs. My aim here is to show that these experiences can arise completely from the forces of Darwinian evolution and the capacities of a highly intelligent brain.

Consider, for example, our feelings of connection to nature. We humans (of the genus homo) have spent most of our evolutionary history in a natural environment – lakes, oceans, trees, soil, grass, birds, mountains, sky. In quantitative terms, we’ve lived close to the land for about 100,000 human generations. When we are in nature, making eye contact with wild animals or looking up at the stars on a clear summer night, we get back in touch with something deep inside of us – hard-wired into our brains. The late distinguished biologist and naturalist E. O. Wilson has used the word “biophilia” to mean this innate instinct to connect with life and the natural world. Modern evolutionary biologists, working with animals and plants whose DNA changes in just a few generations, have demonstrated the not surprising conclusion that living organisms and their ecosystems evolve and adapt to each other.

The crucial first step in survival for all organisms is habitat selection. If you get to the right place, everything else is likely to be easier. Prey become familiar and vulnerable, shelters can be put together quickly, and predators can be managed. Thus, there was almost certainly survival benefit in an attentiveness to nature. Indeed, a great many of the complex structures in the sense organs and the brain that characterize each species serve the primary function of habitat selection.

Just as evolutionary forces probably shaped our feelings of a deep connection to nature, they also probably shaped our need for connection to other human beings, which, in turn, is related to our feelings of being part of something larger than ourselves.

In early hunter-gatherer groups, occupying at least 90 per cent of human history, members of the group would have been highly dependent on each other for survival. Danger was always nearby. The hunters went out for food, while other adults protected the children, kept the fire going, and fortified the cave in communal settings. Being shunned or separated from the group most likely would have brought a quick death.

Social psychologists have noted that there are definite psychological similarities between the kinds of relationships we have with nature and those we have with people. We evolved with certain fundamental social affinities because they helped keep people alive. The most powerful of those is the need to belong.

What about appreciation of beauty? It’s not hard to argue that an appreciation of color and form had survival benefit in its relation to sexual attraction. The primal and evolutionary force behind sexual attraction, of course, is procreation, and procreation is most successful when both partners are healthy and vigorous. Health and vigor, in turn, are associated with well formed body shape, smooth skin, striking facial features, and other aspects of bodily “beauty.” In fact, the neurological reactions to beauty trigger some of the same pleasure centers in the brain as eating, sex, and drugs. Both Darwin and Freud opined that our sense of beauty originated as a strategy to promote reproduction.  

The appreciation of beauty and certain other aspects of spirituality, while not of direct survival benefits themselves, may be byproducts of traits with survival benefit. In such a way, an attraction to beauty might well have other manifestations in addition to its relation to sexual attraction. Thus, we find beautiful the colors of the western sky just after sunset, the patterns formed by constellations of stars, the rise and fall of wind through trees.

My understanding of a scientific basis for these human experiences does not in the slightest diminish my embrace of them. At the same time, that these experiences cannot be reducible to blips on a computer screen does not diminish my belief in the materiality of the world. Mine is a nuanced position. Spirituality, as I have defined it, is not only compatible with a strictly scientific view; it remains at the core of what it means to be human.

I think that this human-centered view of science is particularly important in the paralyzing polarization of our society today. Part of that polarization is a mistrust of science and the institutions of science. Yet we are all human beings. We are connected with each other and to the cosmos around us. And we are all on the same voyage to experience the wonder of the world in our brief lives, and to try to understand it. The endeavor of science is part of our search for who we are and our place in the universe.