Our ordinary language, so useful in everyday life to describe mental life—thinking, intelligence, creativity, consciousness, ethical sensibilities, intention, et al.—is also indispensable in understanding the nature of the human mind, although incomplete in itself. Recent advances in neuroscience, cognitive psychology and science-based philosophy have deepened our knowledge, especially for appreciating how, and in what sense, the mind emerges from complex interactions in the brain. What follows is a series of interrelated summaries of a naturalistic interpretation of the brain/mind relationship. In a broader sense it presents a contemporary perspective of who we are as humans.

·Natural selection, driving the evolution of all living organisms, explains the makeup of the human brain. Although humans are most closely related to chimpanzees, we carry a profound genetic relationship to all animal species. Significantly, the structure of the nervous systems for all mammals, including humans, retain important similarities. While various nervous system components can vary conspicuously in their degree of complexity—human neurons are more complex than those of the smallest mammals—evolutionarily, all mammals are related, having evolved by natural selection from common ancestors. Behaviorally, humans also share much with our animal companions—our cats, horses, dogs, etc.—respond to pleasurable stimuli and when injured, show every evidence of suffering. Animals—and all life—lie along a continuum. While extremes of simplicity and complexity exist within that continuum, no rigid demarcation separates one from the other. The heightened cognitive abilities of humans are largely a matter of degree, although written language and reflective consciousness are, clearly, very advanced abilities.

The human brain is composed of the same stuff as the remainder of the cosmos. My brain’s atoms and molecules could be suddenly interchanged with others from a distant source, and nothing would change in my actions, thinking or feelings. And the electro-chemical interactions of my brain follow the same laws of physics and chemistry as the remainder of the cosmos. But this is not to say the brain’s structure does not create phenomena that contrast with much of the remainder of the world. The heightened cognitive abilities of humans reflect this fact. But just how our abilities come to be—in what sense electro-chemical interactions in the brain bring about human consciousness and the cognitive function we attribute to our mind—is central to scientific and philosophical quandaries concerning the human animal.

The brain is the substrate for all our mental life—everything we ordinarily call the mind. Electro-chemical processes in the brain create what is implied by the phrase “the mind”. Our brain, as well as the remainder of the nervous system, are composed of many categories of cells, with neurons and their respective dendrites, axons, and synapses the most complex. Communication between neurons is electrochemically-based through neurotransmitters (excitatory and inhibitory chemicals). While details of the processes are fascinating, what is crucial is the concept of a fully naturalistic interpretation of phenomena. A world-wide body of neuroscientists have presented descriptions of brain processes fully consistent with the remainder of physics, chemistry and biology—not identical in every detail, certainly, but within the framework of contemporary science. The coherence, depth and detail of empirical studies have made the supportability of non-naturalistic descriptions highly unlikely.

·Asserting that minds—mental phenomena—emerge from brains is a view some find counter-intuitive, but none the less, the concept has considerable justification, and its non-intuitive façade can be addressed. The word “emergence” is regularly used when describing—or trying to explain—the origin of complex systems. So, in an evolutionary sense, complex biological forms, through the process of natural selection, are described as emerging from less elaborate systems. Genetic analysis has consistently verified the path from simple to more complex organisms. And when theorizing about the very origins of terrestrial life—the simplest systems capable of metabolism and replication—biochemists work within the parameters of likely early-earth environments, coupled with their understanding of possible chemical reactions. While no one fully understands how life began, there is no reason to conclude an answer will not be reached, and little doubt that the word “emergence” can be used, and compatible with a naturalistic outlook.

The biological picture of complex organisms evolving from simpler systems is relatively easy to grasp, and using “emergence” as a description is helpful analogically, although by no means complete. But the idea of our minds emerging from the physical substrate of our brains is a significant conceptual leap for many, and in fact, initially puzzling. We should admit this, even though the concept is wholly consistent with all we know about the world, and very likely to be true. Resolving feelings of unease may require adjusting our perspective somewhat. Later in the essay I will describe my own attempt at making this reboot.

Mental phenomena are the creation of the brain—the mind is what the brain “does”. Both phrases “the mind” and “mental phenomena” are inclusive of several distinct, yet overlapping aspects of mental life, making a singular description inadequate. Clarifying these related, yet diverging aspects of the mind will help reduce confusion. First, one aspect, called simply “experience” by the neuroscientist Christof Koch, includes our subjective experiences of seeing, feeling, hearing, loving, disliking, fearing—an endless list of first-person, private experiences. Some are emotion-laden, others less so, such as our perception of colors and shapes (often called phenomenal consciousness). We have an intuitive awareness of this intimate aspect of our individuality, strongly enhancing our sense of self. Identifying the neural correlates of our conscious experience is a yet to be achieved goal of Koch and others in neuroscience. Their success would be a stunning intellectual achievement. A second aspect of the mind is reflective consciousness, or self-awareness, which shares a subjective character with experience, but is also filled with rational and cognitive qualities. The human ability to reflect on the finitude of one’s life—the contingency of a person’s lifetime—may be a capacity not shared with other animals. Reflective consciousness’ cognitive qualities tend to set it apart from phenomenal consciousness/experience.

A third aspect of the mind is its mosaic of cognitive operations, including intelligence, thinking in general, attention, creativity, problem-solving, ethical decisions, etc. These mental operations can be largely non-conscious, as the brain processes our unique histories—a mass of stored information: memories, emotional and conceptual patterns, cognitive skills and biases and desires. We are aware of some aspects of these patterns, but not the specific processing taking place. For the most part our awareness comes later. Systematic, rigorous assessment of this aspect of our mental life is possible, but usually occurs post-event. This observation does not disparage human agency, but, rather, places it in a naturalistic framework, freeing us to better understand the complicated and ambiguous organism we really are. Greater self-knowledge can lead to a more coherent understanding of the nature of our species.

The preceding descriptions of mental phenomena have not explicitly explained how the very idea of the mind’s emergence from physical interactions could be intuitively understood. In other words, what does “emergence” mean in this context? In a naturalistic interpretation, the emergent mind is not viewed as a reality independent from the physical substrate of the brain, but rather a dependent phenomenon. Dependence does not imply unreality, and neither does it suggest our mental experiences, in some vague sense, are “over and above” the physical world. Rather, dependence entails that consciousness, and other mental phenomena, result from the operations of exceedingly intricate systems, in this case the human brain.

For many people, thinking about our species’ evolution from less complex species, and also recognizing how our impressive cognitive skills have developed (emerged) through strictly biological (physical) processes of natural selection, do not create the protracted intellectual angst some experience when pondering consciousness. The acceptance of naturalism in evolution is nearly universal, even given the fact there is no conclusive understanding of how life arose from physics and chemistry—and certainly no intuitive understanding. Why should consciousness be viewed any differently? Similar circumstances seem to surround consciousness, and thinking in general. In fact, this parallel should strengthen the rationale for not inserting non-naturalistic elements into how we grasp the brain/mind relationship.

Much of our mental life is subjectively experienced—our phenomenal consciousness and a multitude of first-person, private experiences. In this sense its reality is assured. We all share an intuitive, first-person understanding of what it is to have feelings of joy, satisfaction or sadness. We sense the full, indubitable reality of subjective experience. But to grasp just how any physical substrate can create the unique character of subjective experience seems unavailable to us. In the near future neuroscience will likely identify the precise neural correlates of consciousness—the specific neurons and brain structure minimally necessary for mental life. But even these insights will establish only a defined causal relationship. Perhaps that is enough. To me, the emergence of consciousness from a physical substrate seems to mirror other non-intuitive aspect of the cosmos, analogous to Quantum Field Theory, where so much is puzzling. All of this is part of our engrossing and fascinating world. Consciousness is a fact of the evolved cosmos. Expecting to know Why or how brute facts fill the known universe may be a mis-conceived search for complete, total knowledge. Future science-based inquiry should support even greater confidence in naturalistic perspectives, but ironically, may also make is easier to accept inescapable constraints to any “final” understanding of the cosmos.

Postscript: This essay shares many topics and lines of reasoning with earlier essays in the blog, especially Consciousness, Human Action and Cognition and Describing Human Agency, although its approach and format differ substantially.