Many discussions in the science and philosophy of consciousness are framed by a profound challenge—searching for an intellectually satisfactory understanding of consciousness, often called the “hard problem” of consciousness. A common thread running through much inquiry is the assumption that consciousness is not observable--consciousness is a felt or experienced phenomenon, never seen or experimentally approachable in a third-person sense. Neuroscientists can specify what parts of the brain become active when particular conscious experiences occur for an individual—correlations between brain activity and experiences—but this kind of analysis is rarely seen as satisfying several criteria for genuinely understanding the phenomenon of felt experience. In addition to identifying specific correlations, what is initially asked for is how certain brain activity leads to specific experiences, how a particular conscious experience is created by specific brain activity. Secondly, and most importantly, how, in principle is it even possible for the brain’s electro-chemical processes to lead to the subjective experiences we have? How can our felt experiences—their immediacy and richness—result from observable, discrete entities in our brain? For many, the subjective, felt character of experiences seem a realm apart from electro-chemical processes. Posed in language of an earlier era, mind appears distinct from matter. The first question seems closer to an issue answerable by a future, more sophisticated neuroscience, but the second captures what is implied when the “hard problem” of consciousness is raised as a uniquely challenging topic. The remainder of this essay will focus on this second and more evasive question, examining several approaches in conceptualizing and using language when thinking about consciousness—possible mindsets, assumptions and perspectives useful in the fascinating interplay of neuroscience and philosophy.

Presuppositions of this Essay: This narrative’s point of departure is a fully naturalistic/evolutionary perspective concerning the origin and character of the human species, including conscious experience—and all of life itself. A simplistic version of reductionism is not implied, although firm acceptance of the following principle is: to be credible, whatever description of human consciousness is given should not be inconsistent with what is known through contemporary biology, chemistry and physics. If an anomaly should occur, thorough vetting is needed, applying the criterion that serious challenges to the foundations of contemporary knowledge require powerful evidence. While it has been historically risky to ever view well-established scientific principles or theories as absolute, some are so strongly supported by tests and operational efficacy that any revision will likely be non-revolutionary. But we do need to retain an openness to new, surprising and strongly supported ideas, no matter what their consequences might be.

An evolutionary perspective is fundamental to how contemporary science understands the character and origins of complex systems, with humans considered the paradigm for complex, biological systems. The sub-atomic realm—micro and very simple—are commonly contrasted with macro systems of exceedingly high complexity. The sub-atomic world is unfathomably small, and in one sense of the word they are “simple”, although described by the perplexing and non-intuitive quantum theory, hardly an uncomplicated task as far as our understanding is concerned. Greater system complexity is reached as we move toward the molecular world, and more so when we consider rudimentary cells, pictured by biochemistry as systems composed of simpler constituents. Systems of even greater complexity are the earliest organisms to inhabit earth. If we leap far ahead to the first mammals—and even further to humans—systems have evolved capable of an extraordinary range of behavior. As far as biological systems are considered, the breadth of an organism’s range of behavior is a useful way of describing its level of complexity.

Electro-chemical Processes creating Consciousness/Experience Itself: It may seem counter-intuitive that what we casually call “physical” processes can bring about conscious experiences—experiences seem so unlike what is habitually visualized as the paradigmatic “physical” realm. To expand our perspective, and see beyond this conceptual block, requires altering the mind-set ordinarily in-play in thinking about consciousness. The result can be a more subtle appreciation for the naturalistic implications of contemporary neuro-science—a merging of science and philosophy.

The micro-world—or quantum world—is tiny from the perspective of macro-objects like ourselves. When we acknowledge that humans are composed of nothing other than what is derived from the quantum world—and those elements in humans are interrelated to a degree of complexity unimaginable intuitively—then it’s possible to accept that both micro and macro are of identical stuff, even if organized so differently. This naturalistic concept—the similarity of micro and macro realms in a fundamental sense—is consistent with all that is currently known through biology, bio-chemistry and physics. The most significant implication of this reasoning is that micro and macro systems are separated only by their respective levels of complexity. What is innocently labeled “physical” should not be contrasted to “conscious” or “mental”, but rather, it makes more sense to exclusively contrast their degrees of complexity, accepting a contemporary version of monism.

Many have argued the following: using the concept of complexity to distinguish humans, who experience consciousness, from other complex systems that do not, cannot adequately describe the occurrence of consciousness or felt experience. A deeper explanation must exist to account for the uniqueness of consciousness. This point of view—claiming an inherent exceptionalism to a small set of advanced organisms, and not on the basis of mere complexity—assumes a bifurcation, a fundamental dualism in the nature of things. This mind-set, to be persuasive, would require a fundamental re-thinking of contemporary science and much of philosophy. The likelihood of success for such a project is not high.

The naturalistic point of view I present assumes the emergence of complex system from less complex progenitors. But this use of the word “emergence”—without an expanded explication—masks the central issue. Referring to my earlier essay “The Second Law of Thermodynamics and Human Meaning” and its passage paraphrasing Steven Pinker, biological systems utilize inputs of energy to resist and counteract entropy, and in the process create order, and through natural selection can evolve into more complex and adaptive systems. This is a fact about the functioning of natural systems, a description of what organisms do, a description supported by an immense set of empirical inquiry. The puzzling and central issue still remaining is the origin of consciousness itself through such processes.

Let’s begin by acknowledging the range of responses that both complex and simple systems generate with respect to their environments. Responses by the smallest multiple cell organisms differ profoundly from more complex systems, such as small mammals, but they respond non-the-less. Interplay between the environment and any system occurs. And plants likewise change and adapt to environmental stimuli. We don’t need to claim “consciousness” for these systems, but they all react to what surrounds them. Humans and other large-brained mammals share a keenly developed awareness of their environment. Those of us living with domestic pets can appreciate their sophisticated responses to our actions, leaving little doubt they experience a range of emotions in ways akin to ours. And all of this makes sense as a function of the evolution of life forms—the fundamental similarity and relatedness of life forms, a spectrum of system complexity. And how can consciousness occur at one end of the spectrum if not by means of evolutionary development? At present, proponents of naturalism are not able to present a fully descriptive and intuitive understanding of how the electro-chemical processes of our brain—in all its sophistication—creates the richness of our conscious experience. Yet it does. Everything that we know is consistent with that view.

The philosopher Philip Goff proposes a modified form of standard naturalism, arguing that mapping the correlations between certain kinds of brain activity and certain experiences—explaining experiences in terms of brain activity—cannot be a sufficient explanation. Goff argues that naturalism, as ordinarily conceived, can describe brain activity only “quantitatively”, whereas experiences are properly described “qualitatively”. Goff in no way denies the reality of brain activity, but believes a crucial element is absent in many naturalistic interpretations, and suggests a conceptual strategy to bridge the quantitative and qualitative aspects of the world. In a way, he is correct. As emphasized earlier, naturalism’s explanation is incomplete. To fill the conceptual gap Goff offers the alternative of a modern-day version of panpsychism: simple forms of consciousness exist at the micro-level, more complex forms of consciousness exist in human and animal brains. Micro-level properties of reality studied by physics exist as exceedingly simple and rarified aspects of consciousness.

Goff’s goal—and one I unquestionably share—is to convincingly reason that what is inside our brains must be continuous (similar) to what is outside (naturalism’s claim as well). But introducing panpsychism as a solution carries a considerable cost—every aspect of the world becomes inclusive of some form of consciousness (whatever that might be), even if very simple. This approach seems to misuse the language of consciousness, distorting distinctions to a degree unnecessary, in effect asking us to view the interactions of micro-systems to one another (fields/particles) as forms of consciousness, in an especially unusual sense of the word. Thinking about these issues will carry greater clarity if we use “consciousness” as a word appropriate for highly complex systems, and exclude its use toward the micro-world.

Unlike Goff’s panpsychism, a fully naturalistic point of view is able to retain important linguistic distinctions, yet earnestly concur with Goff about the fundamental unity of micro and macro. This contemporary variant of naturalism relies on the concept of a profound complexity of inter-relationships forming any consciousness-capable complex system. Also implicit are the acceptance of deep-seated limitations to our potential knowledge, paired with embracing a series of presuppositions sustained by current science-based inquiry. First, whatever characterizes simple systems (fields/particles), such as charge, spin, mass, energy level, etc., is sufficient to enable/entail the occurrence of systems of greater complexity. Second, systems evolve in accordance with the fundamental patterns of the observed universe. Third, specific complex systems have evolved with the capacity for consciousness—including our species’ capacity for self-reflection. For reasons not yet understood, the extreme system complexity found in human brains, and we should assume other appropriately structured systems, creates consciousness and all our subjective experience. To our continuing intellectual disappointment, how to adequately describe these processes is unknown—genuine enigmas exist in understanding the deepest implications of complexity, but a richer understanding of complexity may yield answers. And just as Goff’s suggestion of panpsychism does not provide an intuitive sense of what the intrinsic nature of a micro-world’s very simple forms of consciousness could possibly be, saying the emergence of system complexity through evolutionary change creates the reality of consciousness, can be similarly unsatisfying, leaving us searching for more. But none-the-less’ it is likely correct—in some form.

So let us assume conscious experience—whether self-reflection or the intense experience of colors or sounds—comes about through specific electro-chemical interactions. The very phenomenon of experiencing—our intensely subjective, phenomenal world—has always been the primary and most affecting reality we have. Perhaps that very subjectivity and intensity have become a conceptual barrier keeping us from simply accepting the brute, third-person, objective fact that electro-chemical interactions of the brain create our experiences. The nature of the brain’s processing will continue to be seriously studied and puzzled-over by neuro-science and philosophy, but we need not anguish over the lack of a first-person, intuitive grasp of how subjective experience can actually occur. We may never gain that sort of intimate knowledge. Epistemologically, our intuitive, first person understanding is finite and bracketed.