William Blake: The Ancient of Days, frontispiece to Europe a Prophecy, 1794

British Museum, London

William Blake: The Ancient of Days, frontispiece to Europe a Prophecy, 1794

There are three things that might be meant by “the emergence of the modern mind”: first, the emergence of modern ways of thinking about the universe; second, the emergence of modern conceptions of the mind; and third, the emergence of the mind itself with its distinctive human characteristics. A.C. Grayling, in his new book The Age of Genius, deals with the first of these questions, arguing that the seventeenth century was the pivotal century during which modern thought took its rise, particularly with respect to physics and astronomy. George Makari, in Soul Machine, deals with the second question, tracing the way the old conception of an immaterial and immortal soul gave way to a view that replaced “soul” with “mind” and placed the latter firmly within the body.

Neither author discusses the third question, though it is perfectly legitimate, doubtless requiring us to go back to prehistoric times when Homo sapiens first evolved. It is true that Makari sometimes speaks as if he is discussing that question, as when he refers to “the invention of the mind” or says, “The modern mind was constructed during the Enlightenment”; but presumably this is just a shorthand way of talking about the invention or construction of our modern concept of the mind, not the mind itself. It could hardly be that we went from having an immaterial and immortal soul to having an embodied and mortal mind! I wish Makari had clarified this point so as to ward off any suggestion that he is dealing with the history of the mind itself, as opposed to our ways of thinking and talking about it. The mind is no more created by our ways of conceiving it than the stars are created by our ways of conceiving them (the universe didn’t become heliocentric when Copernicus announced that it was).

Makari’s book is a long but lively account of how ancient and religious conceptions of our inner life (to use the most neutral expression possible) gave way to modern and secular conceptions of ourselves, taking in a great many figures, doctrines, movements, ideologies, and even wars. It tells a story of radical reorientation and fundamental conceptual upheaval. We begin with Plato and Aristotle: the essence of the human individual is his or her immortal soul, which is the seat of reason, the center of virtue (and vice), the cause of bodily motion, and the metaphysical identity of the person. The soul even predates birth, according to Plato: it exists independently of the material world and consists in a kind of wispy abstraction. Thomas Aquinas systematized this idea for the Catholic Church, which became the doctrine known as Thomism.

Once that was accomplished the concept of the soul was deemed sacred and beyond criticism—questioning it could result in a sizzling at the stake. At the same time pagan ideas of the occult and mystical occupied the premodern mind and vied with Christian orthodoxy. Thus modern conceptions had to fight both ancient natural magic and Christian Thomist theology; religious orthodoxy, for its part, was at war with both modern thinking and ancient superstition. As Makari tells the story, this was a long and bitter war of attrition, in which victory was by no means assured, intersecting the political, psychiatric, medical, and philosophical—it was no smooth transition to eventual enlightenment.

Thomas Hobbes was one of the first to question the old edifice, by adopting a general materialism, but he was reviled for his impiety and had little general influence. Marin Mersenne, an adventurous seventeenth-century monk, promoted the new idea of mechanism concerning the physical world, opposing Aristotle and the scholastics, at the same time reserving a special place for the supernatural soul. But it was René Descartes, reclusive and brilliant, who articulated this dualist view most coherently: the body and the rest of nature were just machines operating by physical causation, but the mind was a different kind of substance altogether, whose essence was thought, not extension in space. Still, this raised problems of interaction between mind and body and made some wonder whether mechanism could be pushed all the way, as Hobbes advocated. The Catholic priest Pierre Gassendi soon made the radical suggestion that matter might be able to think and hence there was no need to postulate an immaterial soul. But that was heresy so far as the church was concerned; and thus battle was joined.

Makari’s focus now switches to Oxford, where Francis Bacon’s work on scientific method was much admired. Here men such as Thomas Willis, Christopher Wren, Robert Hooke, and Robert Boyle met to discuss matters both metaphysical and medical. Willis worked on the anatomy of the brain, seeking the basis of the mind, and was interested in disorders of brain and mind; he began to see the mind as a capacity of the material body, not as a separate substance altogether. John Locke was his pupil and was influenced by his naturalistic view of the mind; indeed two of Locke’s central doctrines came from Willis—that the mind is originally a tabula rasa and that the mind might be “thinking matter.”


Locke, himself a physician, eventually produced his Essay Concerning Human Understanding in 1688, which laid out at length and in detail a new conception of the mind. This book had an enormous influence and replaced the old Thomist tradition with a naturalistic theory of the inner life, based on a quasi-mechanical theory of the origin of ideas and a steadfast refusal to adopt anything mystical or occult. The word “soul” gave way to the word “mind” in Locke, and the mind was to be studied as a natural phenomenon. As Voltaire remarked, “Mr. Locke has displayed the human soul, in the same manner as an excellent anatomist explains the springs of the human body.” Meanwhile, in Holland, Baruch Spinoza was formulating his own secular and materialist view of the universe, including man. He was ostracized for his pains and sometimes felt his life to be in danger. Still, his advanced views would seep into the consciousness of his time, rendering the unspeakable spoken.

Part of what is at issue in all this is how we should speak of that aspect of ourselves that we think of as “inner”—and even this term is loaded. We can all agree that we think, have desires, see, choose, and feel pain; but how should we categorize these various phenomena? What stands to them as the word “matter” stands to talk of rocks, tables, and animal bodies? People used to employ the terms “soul” and “spirit,” when these had heavy theological implications; later we employed the word “mind,” but this is not as clear as it might be either. Do bodily sensations such as pain belong to the mind? Are smelling or tasting something to be counted as “mental,” along with thinking and reasoning? Nowadays we speak blithely of the “psychological,” but this word itself derives from the Greek word for soul (psyche). We really have no clear general way to speak of the many phenomena we seek to bring under a single heading. As Makari explains, the battles were terminological as well as metaphysical, with much weight attached to the right word to use; and it was often difficult to translate such words from one language to another.

Makari discusses the impact of these theoretical disputes on what we today would call psychiatry (and he is himself a psychiatrist—a very learned one). Were mania and melancholia, say, disorders of the soul or the mind, the spirit or the brain? Traditionalists held that the immortal soul could not sicken, since that would be an affront to God and incompatible with eternal life; so it had to be the “passions” that were disturbed. Others held that mental disorder was just a malfunction of the nerves. This affected how patients should be treated—with bleedings, induced vomiting, and electric shocks, or with kind words and pleasant diversions. Was madness a matter of possession by demons and lapses into vice, and hence the province of theology and the clergy, or was it a matter for medical men trained in anatomy and physiology?

Thus we witness the tortured history of asylums for the insane and their frequently tortured inhabitants. In the case of the madness of King George III, which had the unfortunate theological consequence that a divinely appointed king might be vulnerable to incurable insanity, Dr. Francis Willis applied both reason and his “piercing eye” to the king, gradually restoring him to sanity (though there were relapses). The mind might become deranged but it could be cured by mental means—not by theology or bodily assault.

Across the Channel, the French writers on sensation, such as Condillac and Diderot, pushed Locke’s picture of the mind yet further, regarding everything about the mind as consisting of sensations—there was for them no rational self or innate capacity for reflection. The mind was constituted by ordinary conscious experience, not some supposed transcendent entity akin to God.

Into this growing psychological naturalism stepped vitalism, emanating mainly from the medical town of Montpellier. As Makari observes, vitalism was an attempt to reanimate the world after its desiccation by mechanism, by inserting an elusive inner force into the gears of the machine, a force that could generate power and purpose—and maybe even explain how matter can think. Studies seemed to suggest that living tissue possessed what the vitalists called “irritability” and “sensibility”—the way muscles retract from a stimulus and nerves transmit information to the mind. There was more to the body than clanking machinery: the ghost is in the body. Accordingly, medicine must pay attention to this force and its disruptions. This led, among other things, to Dr. Samuel-Auguste Tissot suggesting that onanism destroyed the balance of the vital force, resulting in blindness, madness, and death. Rousseau was worried about this conclusion, and surely he was not alone.


And then there was the entrancing Franz Anton Mesmer. Denounced as an atheist and a fraud in Vienna, he turned up in Paris and, well, mesmerized everybody with his talk of “animal magnetism.” People were already excited about electricity, even supposing it to be a cure-all for nervous ills, so that Mesmer’s theory of a “universal fluid,” neither mechanical nor supernatural, found fertile ground. He had discovered, he claimed, a force like Newton’s gravity, but one that acted upon minds, not bodies. Moreover, he had an impressive cure rate, later attributed to his remarkable powers of suggestion rather than the truth of his magnetic speculations. In reality he demonstrated the power of ideas, as opposed to the physical power he claimed to manipulate. It was Benjamin Franklin who finally exposed the would-be magnetist as a charlatan whose work was often just a regression to the occult and alchemical. Mesmer fled Paris and died in bitter obscurity.

Immanuel Kant, writing in the late eighteenth century, revealed the depth of the mind along two axes. First, he gave a systematic analysis of mental operations, distinguishing sensation (“intuition”) and reason, one passive, the other active. The mind has an innate structure that transforms sense impressions according to the “categories of understanding”; it is not the wan blank slate of Locke, for whom the mind was a copier, not a transformer. The mind emerged as far more complex than it was for earlier thinkers—and none of it was supernatural.

Second, Kant argued that the inner nature of the mind transcended human knowledge: in addition to the “phenomenal” mind—the mind we are aware of in introspection—there is also the “noumenal” mind—the mind that underlies our complex mental operations. This hidden mind (not to be confused with the unconscious) was not a reversion to the God-given soul; it was a natural object that happened to be unknowable to us, necessarily so because of the inherent limitations of the human intellect. So much for the Enlightenment’s celebration of the powers of reason!

Kant also thought that the essential nature of matter transcended human knowledge, and that this was not a ground for adopting supernatural explanations of it. It is true that Kant used the German words for soul and spirit (Seele and Geist), not having in German any derivative of the Latin mentis, but this linguistic lack signaled no religious commitments. Kant in fact rejected attempts to prove God’s existence rationally, replacing such supposed knowledge with a principled agnosticism about almost everything. He found no reason to believe in the immortality of the so-called “soul.” In an earlier century Kant would probably have been burned at the stake, as Giordano Bruno was and Galileo nearly was.

Following Kant a spasm of idealism overtook Germany, in the shape of Fichte, Schelling, and Hegel. All was subjectivity, the internal writhing of mind; there was no material world distinct from spirit and absent spirit. The material half of Descartes’s dualism was denied. Kant’s noumenal world was likewise eschewed. But this idealism, by removing matter, effectively removed science: the dependence of mind on body disappeared, and the study of the brain was rendered irrelevant. If there is nothing but mind, how can the science of the body help understand the mind?

At this confused point, around 1800, a counterrevolution was initiated, of startling simplicity: phrenology. Franz Josef Gall swept through Europe giving lectures and demonstrations involving brains and skulls, claiming to have found the seat of the soul in the contours of the head. This was not as absurd as it sounds: after all, the differently shaped skulls of animals correlate with their mental powers, and skull size certainly matters to mind size. But Gall pushed his “craniology” a lot further, asserting that specific personality traits, twenty-seven of them in all, were revealed in the bumps on a person’s skull. He arrived in Paris and wowed audiences with his dissections and measurements—here at last was a real science of mind that made Cartesian dualism obsolete. Measure the bumps and you take the measure of the mind. While some were persuaded by Gall’s theatrics, others could see that his claims were empirically unfounded and really did nothing to solve the problems of the mind or soul—for how could bumps be the basis of consciousness, conscience, and free will? There are bumps all over nature, but not minds. Gall’s popularity duly faded as his many absurdities were noted.

After his exhaustive historical account of all manner of ideas about the mind over three centuries, Makari provides an epilogue in which the significance of these disputes is assessed. The conclusion is not that, thanks to modern science, we have now got it all figured out; it is that we are not much further along than our warring predecessors—only now we don’t need to worry about the pyromaniac tendencies of the church. He writes:

By 1815, all of these positions had been established. When a second wave of mentalism swept through the Western world during the 20th century, these positions would resurface and some of the same dramas would be restaged. Recurrent, unresolved battles over the mind, the soul, and the brain meant modernity would be characterized by these competing conceptions of human nature, each of which held powerful political, scientific, medical, and philosophical ramifications.

Spinoza; drawing by David Levine

In other words, we are still having the same old arguments: “We live in this divided world. Despite the unifying efforts of Enlightenment thinkers, modernity has been structured around fracture lines, like the mind-body problem, the Nature-Nurture problem, free will versus determinism, and secularism or faith.” The merit of Makari’s book is that he enables us to see how our current intellectual predicament reflects a long history of doubt and debate in which the competing notions of machine and soul still struggle. It is enough to make one think that we need a radical reconceptualization of the entire problem, if indeed that were humanly possible.

Anthony Grayling, in his sturdily written and informative new book, presents us with an intellectual history in which progress is far more visible. His thesis, persuasively argued, is that the seventeenth century in particular was crucial in the creation of our modern view of the world: this was the century in which we threw off the shackles of religion, the occult, and uncritical Aristotle-worship. Here many of the same names occur as in Makari’s book: Bacon, Hobbes, Descartes, Mersenne, Gassendi, Locke, Spinoza, Galileo, Bruno, Boyle, Diderot, and many others. Grayling gives us a thorough account of the Thirty Years’ War in Europe, between 1618 and 1648, and its influence on religion, politics, and technology. He speculates that the breakdown of authority during this horrific period was what made freedom of thought and open debate possible, so our modern science actually rests on the heads of millions of dead.

He also notes, less mortifyingly, the importance of the development of a reliable postal service, run by the enterprising Taxis family, in enabling savants of the time to be in scholarly communication. This permitted dispersed thinkers to engage in collective research, not just individual lucubration. Grayling rightly notes that the cooperative approach, first recommended by Francis Bacon, was essential to making science open to peer review and public verification, and not just a matter of the lone guru issuing his idiosyncratic pronouncements.

The rise of science and secular philosophy required a new conception of knowledge in which observation, not authority, was the source of knowledge. The learned man (and it generally was a man) had hitherto been conceived as someone steeped in sacred texts, whether biblical or Hellenic; his knowledge was essentially derivative and secondhand. He knew what he knew because he had learned it from someone in authority, generally from books. But the new model of knowledge was not textual: it was sensory. To find out about the world you had to observe it with your senses and then make inferences using your faculty of reason, not study ancient texts.

It is hard for us now to see that this was a revolutionary thought, and in its very nature undermined authority, because authority was no longer the road to knowledge. When Galileo looked through his telescope and claimed to know something of the stars, he was in effect questioning centuries of assumptions about how knowledge could be acquired. This kind of empiricism involves rejecting the entire hierarchy of learning that had been taken for granted for centuries: senses, not texts; nature, not pronouncements from on high. So-called revelation produced error, not knowledge.

Grayling has an interesting discussion of Newton, who straddles the two worlds that preceded and followed him. On the one hand, Newton is the consummate scientist, rigorous, mathematical, and hardheaded; on the other hand, he was a very credulous believer in the occult and magical. Alchemy and numerology were as real to him as mass and force. It is hard today to think of a scientist who combines such extremes; and the reason is that in Newton’s time the old ways still had a substantial hold even on the most advanced thinkers.

The effort to transcend millennia of superstition was much harder than we tend to suppose. To think and write as Hobbes and Spinoza did took not just physical courage in the face of possible persecution but also a profound internal restructuring of all that had been thought since records began. And it is not surprising that the revolution in astronomy begun by Copernicus and Galileo, replacing the earth with the sun as the center of the universe (as it was then conceived), was immensely difficult for people to accept; for it usurped not just the Bible and church authority but also the entire human conception of our place in Creation. It made people think, alarmingly, that even the most cherished and certain of assumptions could be simply mistaken.

The lack of inevitability about what was inaugurated in Europe in the seventeenth century, and the many forces that were arrayed against the Enlightenment, make one wonder about its staying power. Certainly without constant vigilance a new Dark Age could conceivably come, as it once did following the Greek efflorescence. Here is Grayling’s dry appraisal:

At the beginning of the [seventeenth] century the Church was prepared to kill in order to keep control of what can be thought; by the century’s end this was no longer possible in Europe. Alas, it remains possible in a number of regions in today’s world—a state of affairs which shows that those parts of the world still await their seventeenth century and its offspring, the following century’s Enlightenment.