CONSCIOUSNESS REDUX Exploring the riddle of our existence
tural and scientific meaning, as well as and Plato differed with Aristotle, argu- an array of underlying assumptions, ing for the immortality of the soul on the some clearly articulated, others wholly death of the body. ignored. These meanings adapt over Dominican friar and Scholastic phi- time as society changes in response to losopher Thomas Aquinas (1225–1274) CONSCIOUSNESS wars and revolutions, catastrophes, casts these classical Greek ideas into a trade and treaties, invention and discov- form that meshed with Christian ones ery. Psychiatrist and historian George and would remain an important influ- Constructing Makari tries to illuminate this historical ence through the Middle Ages. A trium- evolution in his Soul Machine: The In- virate of three souls makes up every liv- the Modern vention of the Modern Mind, published ing human—a nutrient soul common to last November by W. W. Norton. His in- all organisms, a sensitive (or appetitive) Mind tellectual history masterfully describes soul characteristic of animals and peo- how consciousness, mind and soul are ple, and a rational soul that is immortal, From Aristotle to Watson, views on shape-shifters that philosophers, theo- a repository of humanity’s godhood, mind, brain and soul have evolved. logians, scholars, scientists and physi- lifting people above the natural, materi- A brilliant new book adds perspective cians seek to tame, by conceptualizing, al world. The rational soul could not be- defining, reifying, denying and redefin- come sick, because it was immaterial, Unlike any other empirical object ing these terms through the ages to come but it could be possessed by the Devil or in Nature, the mind’s presence is to grips with the mystery that is our in- some of his demonic servants. Doctors immediately apparent to itself, but ner life. could not help those so afflicted, but ec- opaque to all external observers. clesiastical authority could and did— —George Makari, A Brief History of the Soul saving their immortal souls one way or Soul Machine, 2015 The systematic search for answers another as attested to by the fiery death goes back to Aristotle (384–322 b.c.), of tens of thousands of both female and My life, as well as this column, is dedi- foremost of all biologists, taxonomists, male witches. cated to understanding the conscious embryologists and evolutionists. His De For close to four centuries, this Thom mind and how it relates to the brain. Anima (literally On the Soul) classifies ist philosophy was the dominant intel- This presupposes that you, the reader, the nature of living things and discusses lectual narrative for Christians, noble- and I have a precise sense of what is his notion of the soul (psyche), which for men and peasants alike. It offered solace referred to by such seemingly innocent him means the essence of a thing. The to the weary and the dying, and it justi- terms as “consciousness” and “mind.” soul defines an organism. All living fied the divine right and the absolute And lest it be forgotten, the allied con- things have souls with distinct faculties. power of kings and queens. Yet decades cept of “soul” (or spirit), banned from The vegetative soul embodies the life of bloody religious warfare among scientific discourse, continues to remain force that distinguishes living matter, be Christians for the “one true faith” dur- profoundly meaningful to vast throngs it plants, animals or people, from inani- ing the first half of the 17th century led of humankind here and abroad. mate matter, such as a rock. It supports to widespread questioning of these re- But there’s the rub! Unlike such ma- nutrition, growth and reproduction. ceived truths. terial objects as “egg,” “dog” or “brain,” The sensitive soul enables sense percep- This is the chronological starting this triptych of intangible concepts is a tion, pain and pleasure, memory, imag- point for Soul Machine—it follows the historical construct, endowed with a ination and motion. It is common to an- philosophers, savants, doctors, writers universe of religious, metaphysical, cul- imals and to humans. Both the vegeta- and revolutionaries of the English, Scot- tive and the sensitive souls are corporeal tish, French and German Enlightenment and, therefore, mortal. It is the rational as they transmogrified the rational soul BY CHRISTOF KOCH soul, unique to people, that is responsi- over two centuries into a mechanized,
ble for intellect, thought and reason. naturalized and desacralized thing. This ) The rational soul constitutes the quiddi- process gave birth to psychology, neu- Christof Koch is president Koch and chief scientific officer ty of what it is to be a human. For Aris- rology and psychiatry and the knowl-
of the Allen Institute for Brain CABE (
totle, although the rational soul is im- edge that we, children of the 21st centu- C Science in Seattle. He serves on Scientific American Mind’s material, it cannot exist independent of ry, are evolved from apes.
board of advisers. the body. Famously, of course, Socrates All of this starts with the reclusive SEAN M
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Frenchman René Descartes (1596–1650) caused by particles of various shapes dualism divided the world into two mag- and the radical and outspoken English- that jostle one another and move isteria: a mechanistic one that was to be man Thomas Hobbes (1588–1679). The about. Nothing more and nothing less. the playground of experimental philos- former is one of the fathers of modern Descartes postulated that everything ophers, the precursors of modern scien- science (he linked algebra to geometry, under the sun is made out of one of two tists and clinicians, and a theological thereby giving us the Cartesian coordi- substances. The stuff that can be touched one, the dominion of the immaterial and nate system). Descartes replaced the and that has spatial extension is res ex- immortal soul. Descartes thereby safe- moth-eaten final causes and forms of the tensa; it includes the bodies and brains guarded Christian dogma and ecclesias- Scholastics—wood burns because it pos- of animals and people. The stuff that tical authority. sesses an inherent form that seeks to cannot be seen, that does not have ex- This dichotomy won Descartes the burn—by mechanistic ones. In particu- tension, is thinking stuff, res cogitans. It enmity of Hobbes, who published his lar, he argued that the movements and alone enables humans to reason, to celebrated Leviathan, a bold materialis-
GÉRARD DUBOIS actions of animals and humans are speak and to freely decide. Descartes’s tic manifesto, considered the foundation
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for Western political philosophy. For Understanding, written while in exile in flection and by association. How the Hobbes, everything was made out of Holland and first published in an mind could carry out these tasks was a matter. There was no necessity for any abridged French edition. Locke’s work mystery for Locke as it was for Descartes, special thinking substance. Matter helped to turn the soul into something Hobbes and everybody else. For how could think. Even though the bulk of closer to the modern mind (from the Old mere brain matter could think, reason or Leviathan was a book-length argument English mynde), the theater of our sub- speak was inexplicable given the me- for absolute monarchy (rather than reli- jective experience. The mind is populat- chanics and chemistry of the day. Thus, gious authority) to prevent the kind of ed by ideas that ultimately derive from Locke postulated that God had super- religiously motivated bloodshed of the the outside, from sensations, for the added active forces to brain matter. European Wars of Religion (circa 1524– mind at birth is an empty slate, a tabula Common to Descartes, Hobbes, 1648), Hobbes was considered blasphe- rasa. The ideas of God, justice, mathe- Locke, Baruch Spinoza and other radical mous, and his books were burned. matics and the self, as well as everyday thinkers was a disdain for superstition. English doctor John Locke (1632– objects, whether implements, machines, Makari cites an entry from Locke’s jour- 1704) further naturalized the rational animals or people, are not innate. Rath- nal: “The three great things that govern soul in his Essay Concerning Human er they are learned by experience, by re- mankind are reason, passion, and super- stition. The first governs a few, the two last share the bulk of mankind and pos- sess them in their turns. But superstition most powerfully produces the greatest mischief.” Two centuries hence, Fyodor Dostoyevsky’s Grand Inquisitor under - stood this mind-set well: “the only three forces that are able to conquer and hold captive forever the conscience of these weak rebels for their own happiness ... are miracle, mystery and authority.” To- day, another two centuries onward, hu- manity continues to battle these forces. As the mind of the closing years of the 17th century had lost many of its heavenly attributes and had become a part of nature, it could now suffer the corruptions all matter is prey to; it could become dysfunctional, sick or afflicted with melancholia (a widespread ail- ment). Or it could be fallible and form misassociations that led to cognitive er- rors, explaining the rising tide of reli- gious fanatics, enthusiasts and prophets: the Anabaptists, Methodists, Seekers, Quakers, and other self-avowed divine
messengers who wandered the world, Getty Images preaching their own interpretation of God and the Bible. Perhaps God was not speaking through them, but rather they were simply deluded. Likewise, perhaps witches were not truly possessed. May- be they were simply ill, sick to their souls or crazy, and they should not be burned. Superstition—as exemplified in William Blake’s The Witch of Endor—received withering critiques If people had unbalanced minds,
from Enlightenment philosophers, including René Descartes, Thomas Hobbes and John Locke. could these be righted? Could they be NATIONAL GALLERIES OF SCOTLAND
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The odd behaviors of King George III entranced all his subjects. The 1994 film The Madness of King George rendered an account of this period.
cured? How so? By confining them to madhouses? What kind of therapies would work best? How can one tell a mad person from an eccentric? These questions captivated the United King- dom in response to the bizarre behavior of King George III, the sovereign who lost the American colonies and triggered a political crisis concerning his sanity and whether and how it could be re- stored. Echoes of these controversies can be heard even today in the ongoing dis- pute concerning who to blame for mass shootings—deranged individuals or gun ownership and cultural factors. physicians Franz Joseph Gall (1758– nals, lunatics, the eminent and the (in)- Ever so slowly, with countless set- 1828) and his assistant Johann Spurz famous. It eventually lost favor as a rep- backs, as the decades turned into a cen- heim (1776–1832). Based on systematic utable scientific method but lingered on tury and then two, religious explana- dissection of human and animal brains, until the early 20th century. tions of idiosyncratic behaviors turned Gall formulated a thoroughly material- Although there is no discernible rela- into clinical ones, with attendant men- istic, empirically based account of the tion between the morphology of the ex- tal asylums and specialist doctors to brain as the sole organ of the mind, one ternal skull and the size and function of treat the afflicted, now considered nei- that is not homogeneous but an aggre- the underlying neural tissue, Gall’s insis- ther evil nor touched by God but pa- gate of distinct parts and, as a conse- tence on localization for specific cogni- tients in need of help. quence, distinct “functions.” Gall ar- tive functions in the cerebral cortex Makari rightfully spends many pag- gued for 27 functions, each one assigned found validation in 1848 through the es on Prussian astronomer and philoso- to different and distinct regions of the work of Parisian neurologist Paul Broca. pher Immanuel Kant (1724–1804), who brain. Every individual inherits a sepa- The physician presented the landmark did more than anybody else to delimit rate set of organs, some smaller, some case of a patient unable to speak except and plumb what the mind can know and larger, thus explaining individual differ- for the single word “tan.” His brain what reason can deduce about the world. ences. These views of the brain as a ma- proved to have suffered damage to its With rapierlike precision, Kant argued chine for producing thought and memo- left frontal lobe. Thus, Broca concluded that our mind can never penetrate to the ry clashed with religious sentiments and that meaningful speech was closely re- true nature of things. public morality to such an extent that lated to this region. An analysis of a sec- Gall had to leave Vienna and settle in ond patient fortified his conclusion that Of Spirits and the Profane postrevolutionary Paris. a circumscribed region in the frontal The book does an outstanding job of Using the detailed curvature, shape cortex—the left inferior frontal gyrus, relating changing epistemological narra- and extent of the skull, Gall and Spurz named Broca’s area—was responsible tives to the politics of the day. Posses- heim claimed to be able to infer the size for productive speech, that most human sions and exorcisms provided visible and import of the organ underneath the of all behaviors. proof of the reality of the spiritual world. cranium and thereby diagnose the men- Overall, Soul Machine is a monumen- If these were now profane matters, sub- tal character of the individual exam- tal work, replete with reproductions of ject to medicine and reason, where did ined. Their phrenological method contemporary engravings, that describes this leave the divine justifications for the proved immensely popular, as it ap- in sometimes overwhelming detail the absolute rights of monarchs? pealed to the growing middle class as work of a large cast of individuals—and Soul Machine ends in the mid-19th scientific, sophisticated and modern. their influences on one another—over the
KEITH HAMSHERE Getty Images century, with a portrayal of German Phrenology was used to classify crimi- course of several centuries.
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Descartes theorized that the pineal gland—denoted “H” in this illustration from his 1662 De Homine—was the “seat of the soul.”
It seems strange that Makari stops cessing paradigm. In this narrative (dom- that prevails, one as familiar to us all as short of describing Charles Darwin’s in- inant in academic psychology and neuro- mother’s milk. fluence on the conception of the human science), the brain transforms incoming Descartes’s ideas were rooted in his mind as an evolutionary refinement, an sensory information to yield an internal inability to conceive of procedures and extension of the minds of apes, monkeys representation of the external world. In mechanisms to explain intelligence, and other animals, shaped by natural se- conjunction with emotional and cogni- reasoning and language. In the 17th cen- lection to fit a particular socioecological tive states and both conscious and uncon- tury nobody could envision how the niche. That is, we have the cognitive ap- scious memories, the mind generates—or mind-less application of innumerable, paratus that we have precisely because it enabled our proximal and distal ances- tors to better survive the struggle for ex- WHAT WOULD ARISTOTLE, AQUINAS AND istence. Our genetic endowment pro- foundly shapes the way we apprehend DESCARTES HAVE MADE OF A ROOMBA, WHICH the world. This inborn bias to see the CLEVERLY CLEANS FLOORS, OR OF IBM’S WATSON, world in a particular way—for example, for most of us in a combination of three WHICH BESTED HUMANS IN JEOPARDY? colors—also irredeemably shapes our perception and ultimately our knowl- , LONDON , edge about the world. This echoes Kant’s computes, as the cognoscenti would have meticulously detailed, step-by-step in- Y celebrated argument for the existence of it—an appropriate response and gener- structions, what we today refer to as knowledge that cannot be logically de- ates the associated motor behaviors. algorithms, could get a computing rived yet is prior to our experience (syn- Think of the human body as a robot, machine to play chess or Go, recognize thetic a priori proposition). with its brain as a neuromorphic com- faces, label photographs and translate My far bigger complaint with Soul puter. Thanks to Steve Jobs, Bill Gates, Web pages. Descartes had to appeal to a OF WELLCOME LIBRAR WELLCOME OF Machine is the book’s complete neglect of Paul Allen and the other visionary entre- mysterious, ethereal substance that, in Y
the dominant strand of modern thinking preneurs who gifted us with personal some nebulous manner, did the thinking RTES U
about the mind—the information-pro- computers, this is the view of the mind and reasoning. CO
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A mere couple of decades later the seed of the computational paradigm was laid down by German rationalist philos- opher, scientist and polymath Gottfried Wilhelm Leibniz (1646–1716), who de- veloped the binary number system and, in fierce competition with Isaac Newton, invented calculus. He was on a lifelong quest to develop a universal calculus, what he termed a “calculus ratiocinator,” in conjunction with a universal concep- tual language. If he had been capable at the time of creating such a thing, it would have resembled either a proto–computer Polymath Gottfried Wilhelm Leibniz invented an early digital calculator at the end program (software) or a description of a of the 17th century, a manual processing unit capable of performing the basic arithmetical powerful calculating machine (hard- operations of addition, subtraction, multiplication and division. ware). Leibniz was looking for ways to cast any dispute into a rigorous mathe- ry, with profound implications for our anything and can be conscious in the matical form that could then be evaluat- contemporary view of the mind. One way that people are remains controver- ed for its truth. As he wrote: strand ushered in neural networks and sial, with at least one popular theory of computational neuroscience, demon- consciousness denying it. (To go still fur- The only way to rectify our rea- strating how large networks of intercon- ther and achieve a naturalized immortal- sonings is to make them as tangi- nected nodes can learn to recognize let- ity, some of the more enthusiastic techno ble as those of the Mathemati- ters, faces or objects, navigate a complex utopians postulate a heaven in the appro- cians, so that we can find our error environment, speak and reason. The sec- priately located Cloud, to which our dig- at a glance, and when there are dis- ond strand completely upended society ital simulacrum will eventually be up- putes among persons, we can sim- and our way of life because it gave rise to loaded, provided we practice the right ply say: Let us calculate, without digital computers, first in the shape of a brain-freezing technique.) further ado, to see who is right. few large university- or government-op- Supernatural meaning has been erated centers, then on millions of desks leeched from the modern conception of Leibniz was no mere theoretician but in offices, and now living in the pockets the computational mind by the acid bath an all-around talent who designed and and hands of billions of people. of the Enlightenment. No brain, never built an early general digital calculator. Even more critical, computers gave mind! Yet by no means has our under- His dream of a calculus ratiocinator mo- rise to the idea and later the practice of standing of the interbraided leitmotifs of tivated logicians of the late 19th and ear- artificial intelligence, the design of ma- Soul Machine— consciousness, mind ly 20th centuries, culminating in the chine minds whose performance is nar- and soul—reached its final apogee. It will 1930s with work by Kurt Gödel, Alonzo rowly defined but increasingly able to continue to evolve as scientists, clinicians Church and Alan Turing that gave us match and exceed what the human mind and philosophers, newly joined by engi- two things. First, their labors placed ab- is capable of. What would Aristotle, neers, seek an ever more precise carving solute and formal limits on what can be Aquinas and Descartes have made of a of nature at its joints, to use a beautiful proved by mathematics, bringing to an Roomba, a popular disk-shaped house- Platonic idiom. end its ancient, aspirational dream of hold robot for cleaning floors, or of Soul Machine is an eminently read- formalizing truth, of constructing a uni- IBM’s Watson, the computer program able account of how these concepts are versal alethiometer, that is, a truth me- that understands and speaks English and shaped and determined by historical and ter. Second, it gave birth to the universal that bested humans in the quiz show cultural contingency in ways that science Turing machine, a dynamic model of game Jeopardy? Judged purely by their usually chooses to ignore. M how any mathematical procedure can be behaviors, one would have to accord implemented and evaluated on a very these technologies as possessing both simple machine. sensitive and rational souls capable of MORE TO EXPLORE These conceptual breakthroughs fed achieving res cogitans. Yet the extent to ■■Soul Machine: The Invention of the Modern
COURTESY OF COMPUTER HISTORY MUSEUM two related but distinct streams of inqui- which digital computers can experience Mind. George Makari. W. W. Norton, 2015.
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