The Skeptics Society & Skeptic magazine

The Soul of Consciousness

a book review by Robert L. Martone

Consciousness is an enigmatic hallmark of human existence. With his book, Soul Dust: The Magic of Consciousness, psychologist Nicholas Humphrey takes an ambitious approach to the problems of consciousness with a scope that encompasses science, literature and philosophy.

Humphrey’s essential thesis is that consciousness is the key characteristic that differentiates humans from most if not all other living beings, and that consciousness must be the result of an evolutionary process driven by a positive selective pressure: consciousness confers a selective advantage that enhances the survival and success of conscious beings. Humphrey has three objectives; first, to define consciousness; second, to propose the means by which the neural circuitry required for consciousness could emerge from neural substrates present in non-conscious organisms; finally, to define the selective advantage that consciousness offers conscious beings.

Humphrey defines consciousness in terms of the familiar model of the “Cartesian Theater” wherein our experience of consciousness is merely an internal representation of the external world played out upon a mental stage. He postulates that consciousness emerged from the gradual internalization of stimulus-response circuits. In the most primitive state, these circuits consist of neuronal loops that direct responses at the site of stimulation, while in the more advanced state, both the sensory and motor systems are internalized in the brain, and the stimulus-response loop may be entirely internal to the organism. Here again, Humphrey treads familiar ground, with inspiration from Hofstadter’s “strange loops,”¹ but he missed an opportunity to explore in this context “mirror neurons”—those motor neurons first described by Rizzolatti that are activated in the brain of an animal either when that animal performs an activity or when it observes that same activity performed by another animal.²

What, then, is the selective advantage that drives consciousness? Humphrey posits that consciousness evolved simply because humans enjoyed being conscious. This psychic or metaphysical benefit conferred upon conscious humans is derived not so much from adaptation to the physical world, according to Humphrey, as it is to a metaphysical niche that he calls the “Soul Niche.”

Perhaps one should not expect extraordinary scientific scholarship in a book that contains the word “soul” in the title and “magic” in the subtitle, but Humphrey appears to have ambitions to be taken seriously, or at least to be seen as a provocateur. When justifying his use of the term “soul,” he asks, “Should I really be using it so freely? Doesn’t the word “soul” carry too much baggage? Yes it does, and I should—I should because it does” (156). A certain narcissism creeps into his narrative at times as when, for example, he gushed with Oprahesque abandon, “For if you have a miracle at your very center, then miraculous you are (emphasis his, 138).” He supports his contention that consciousness provided positive selective pressure through human enjoyment of consciousness with life-affirming passages from Rupert Brooke, Gerald Manley Hopkins and even selections from The Sound of Music, but he is apparently less familiar with Nietzsche, Styron or Bukowski. Nor does the prevalence of depression (9.5% of the adult population in the U.S., 10% in the UK) dissuade him from his arguments, which are at times embarrassingly provincial. For example, he contemplates what he supposes would be the tedious world of being human without consciousness, noting, “We need to ask whether a dreary world is necessarily one in which an animal or a human would lead a less successful life. We need to establish what, if any, is the biological advantage of being awestruck” (120). This leads one to wonder whether he is completely unaware of how much of humanity—all of them quite conscious—live in such a dreary world, with very little to prompt awe, and with little hope for escape from the anguish of hunger and destitution?

Consciousness emerges with age, and the consciousness of an infant is very different from that of an adolescent, which in turn is removed from that of a middle-aged adult. Throughout human existence from the Paleolithic era through early modern times, life expectancy was around 30 years, and while humans are sexually mature in their teens, the human brain—the substrate of consciousness—continues to develop until the mid 20s. If consciousness were to have evolved, the aspects of consciousness that conferred positive selective pressure were likely those that are manifest in the teen years. Humphrey acknowledges this emergence, yet still fumbles with it in his arguments. For example, he cites childhood curiosity as exemplifying the enjoyment of consciousness: “Human children in the first three years of life are consumed by a desire to explore and experiment with objects” (123), yet later acknowledges that human babies lack the unified sense of self that underlies consciousness. Similarly, he describes the “presentism” of a baby enjoying a bath, but it is precisely that presentism—that lack of historical context and indifference to the future—that he compared to the reveries of a gnat or a jackdaw and that would characterize any pre-conscious organism, infants included. Differences between teens and older adults that manifest in, for example, lower risk aversion are left fully unexplored in this work.

It may well be that humans created a metaphysical niche of their own, however, success and failure in that niche may be far more consequential than Humphrey’s rather banal choice between enjoyment and dreariness. Humphrey stumbles upon it when he states that, “human beings’ fear of death must always have been highly visible to natural selection—and hence so must have been the consciousness that lies behind it” (96–97). Has this fear of death led to avoidance of war or of killing in human culture? Obviously not. Rather, it may be that consciousness, and the theory of mind that is part of it, is essential to protect humans from their fiercest competitors—other humans. It is in this murderously competitive realm with other people that internalization of stimulus-response loops becomes important by providing a level of secrecy regarding one’s own knowledge and intentions. Similarly, mirror neurons would offer a selective advantage by providing an internalization of another’s intentions.

Humphrey touches upon the historical context of consciousness, stating that, “during the Renaissance [attitudes] shifted from a sense of unconscious fusion with the world towards a state of conscious individuation” (141). Yet Renaissance humanism did not rouse a sleeping medieval Europe to consciousness. In fact, it is narcissism, that “state of detached self-absorption” (106) that is the true focus of Humphrey’s work rather than consciousness per se, and the reason that this work falls short in providing a compelling explanation of consciousness.