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- Koch Christof Koch is president 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 22 SCIENTIFIC AMERICAN MIND MAY/JUne 2016 miq316Koch4p.indd 22 3/1/16 5:23 PM Exploring the riddle of our existence 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 MIND.SCIENTIFICAMERICAN.COM SCIENTIFIC AMERICAN MIND 23 miq316Koch3p.indd 23 2/29/16 6:29 PM CONSCIOUSNESS REDUX 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, Fyo dor 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.