Descartes' Bones (4 page)

The
Discourse on the Method,
which appeared seventeen years later and summarized the work he had done in that time, was his first published book. To be precise, it was four short books packaged together. The last three were essays devoted to light and optics, geometry and geological and weather phenomena. They included the first or among the first credible accounts of the law of refraction, near- and farsightedness, the nature of wind, cloud formation, and rainbows, as well as the elaboration of analytic geometry.

But it was the introductory essay, the “Discourse on the Method” itself, a mere seventy-eight pages, that gave this small, vain, vindictive, peripatetic, ambitious Frenchman a status among his contemporaries and those who followed unequaled since Aristotle. He was not the greatest mathematician of the seventeenth century (Isaac Newton, a generation older, would surely win that title), or the most influential scientist (here there might be a tie between Newton and Galileo), and one could argue that both Spinoza and Leibniz were more refined philosophers. But Descartes could be considered, as one current philosopher puts it, “the father not just of modern philosophy but, in important respects, of modern culture—of modern Western culture and later, through export of its ideas, of much of modern world culture,” and the
Discourse on the Method
is the first reason why. This little essay has been called “the dividing line in the history of thought. Everything that came before it is old; everything that came after it is new.”

A
S FAR BACK AS
his school days Descartes had concluded that the place where the traditional approach to knowledge was flawed was at the base: its method of going about the business of understanding. There was no end of brilliance and subtlety in the ancient writers, but if they were starting from a swampy foundation their edifices weren't supportable. Take Aristotle's elemental building blocks of nature: why earth, air, water, and fire? What is the rationale for supposing that what is simply most evident to the senses is necessarily the base of reality? Or consider Thomas Aquinas, the finest of the Scholastic thinkers, who devoted his razor intellect to such things as an elaborate “proof” of the existence of angels, which included an analysis of their numbers, varieties, substance, intelligence, and origin and resolved such questions as whether, in moving from one place to another, an angel passes through intermediate space. How could one of the greatest minds in history get itself into such convoluted alleys of reasoning? Or Plato, with his theory of forms, according to which the tree out the window is not itself real but merely a reflection of the eternal form “tree” and the keyboard on which I type is actually an imperfect approximation of a perfect nonmaterial form—call it “keyboardness”—that was created by God and exists in eternity.

Layers of tradition had built up around such categories for understanding reality. Centuries of robed scholars and scribes had bent in tallow-tapered light over parchment sheets and leather-bound manuscripts, mouthing words, quill-scratching, rubricating, memorizing, parsing and analyzing and adding levels to the hoary infrastructure that had these categories as elements and that was applied as an increasingly unwieldy tool to explain natural phenomena, human behavior, history, the universe. But on what ground did they stand, these classifications? How could one trust them? How do we know they aren't nonsense? Or, if they were true, couldn't we expect that great things would have arisen from knowledge built upon such bases? As Descartes put it, devastatingly, “The best way of proving the falsity of Aristotle's principles is to point out that they have not enabled any progress to be made in all the many centuries in which they have been followed.”

What kind of method, then, would yield progress? Descartes was clear as to his ultimate aim. Unlike philosophers of later eras, who would devote themselves to questions of the order of “Why is there something rather than nothing?” he was full-blooded in his inquiry: he was after the kind of philosophy that would take the world by the throat, that would make people “the lords and masters of nature.”

At first glance, his way of proceeding doesn't seem to make sense. For a universal measure one might reasonably look outward, like a navigator with a sextant: to the stars, to the distant horizon. Instead, his break from tradition is signaled, first, stylistically: the
Discourse on the Method
is written in the first person. A byproduct is that one of the world's great works of philosophy is also one of the most readable. And it serves as an appropriate launching point for a new era in which the focus is on the individual. The
Discourse
begins not with mathematical formulas or scientific propositions, not with the lining up of outside authorities, but with a living human being—Descartes himself—sitting alone, thinking. There is atmosphere in the text, snugness: you can almost hear the crackling of the fire in the background. The realm we're in is familiar: it's that of the novel, the narrative, the play, and the film. It's human and, yes, modern.

All of these modern art forms involve, in addition to a personal focus, a central crisis on which the story turns, and so does this first work of modern philosophy. The crisis is a loss of meaning, and the quest is a search for truth, for something to believe in. Descartes' strategy was to assume that Aristotle's entire approach to nature, to reality, is wrong and then to assume the same for Aquinas, Plato, Duns Scotus, William of Occam, and all the revered writers. He ceremonially placed the Bible—from Adam and Eve to the Hebrew prophets to the resurrection of Jesus Christ—in the same dustbin. He continued slashing every such thought and idea until he came to a proposition that was impossible to deny. It was both a philosophical and a psychological undertaking, and to it he appended a “don't try this at home” caution: “The single design to strip one's self of all past beliefs is one that ought not to be taken by every one.”

Maybe grand abstract writings needed to be dismissed in this way, but what about the things that are right in front of me? What about, as Descartes put it in
Meditations on the First Philosophy,
the simple fact “that I am in this place, seated by the fire, clothed in a winter dressing-gown, that I hold in my hands this piece of paper”? Even these things fell by the wayside. The senses can't be trusted either. The senses deceive. I might be dreaming, or drugged, or deceived by a malicious deity. If we are being serious about this project, then sights and smells and tastes, no matter how self-evident, must also be doubted. Strictly speaking, I can't even be sure of the reality of my own body.

Which leaves what? At the end of this remorseless reduction there is only one thing that remains, one proposition that can't be denied, one sound, as it were, in the universe, like the lonely ticking of a clock. It is the sound of the thinker's own thoughts. For can I doubt that thoughts are occurring right now, including this one? No: it's not logically possible. So, humble though it is, we can call this a ground: bedrock.

In this way, Descartes became one of those rare figures in history who have given the world a sentence that is a touchstone. “I am the way, the truth, and the life” was such an utterance, standing on one side of Descartes and his era. On the other side we have “E=mc2.” As philosophers since have pointed out, “I think, therefore I am,” or “Je pense, donc je suis,” or “Cogito, ergo sum,” does not fully encompass what Descartes intended. Once the acid of his methodological doubt had eaten its way through everything else, what he was left with was not, technically, even an “I” but merely the realization that there was thinking going on. More correct than “I think, therefore I am” would be “Thinking is taking place, therefore there must be that which thinks.” But that hardly has the snap to make it a slogan fit for generations of T-shirts and cartoon panels.

The irony is that in shifting the focus onto the individual human mind, which everyone agrees can be a pretty flimsy and wayward organ, Descartes had arrived at the closest thing to a certain basis for knowledge. If my own thoughts are the only indubitable ground I can stand on, apparently they aren't so flimsy after all, at least not all the time. As an early follower of Descartes put it, “Doubt is the beginning of an undoubtable philosophy.” Therefore the mind and its “good sense”—that is to say, human reason—are the only basis for judging whether a thing is true. With the “cogito,” as philosophers abbreviate it, and with the theory of knowledge that arises from it, which Descartes outlined in the
Discourse on the Method
and later works, human reason supplanted received wisdom. Once Descartes had established the base, he and others could rebuild the edifice of knowledge. But it would be different from what it had been. Everything would be different.

T
HE MASSIVE
G
OTHIC CHURCH
tower that dominates the skyline of Utrecht stands oddly alone in the middle of a central square of that Dutch city today, separated from its cathedral by a wide swath of paving stones. The explanation for this anomaly is that the nave that connected the two structures collapsed during a violent storm in 1674 and was never rebuilt. With this exception, the exquisitely preserved old city center, with its sunken canals, twisty streets, and gabled brick façades, is not so different from the way it would have appeared in the year 1638, when a bluff forty-year-old medical doctor named Hendrik de Roy—who was known by the Latinized form of his name, Regius—swept determinedly into the building connected to the cathedral, the newly christened Utrecht University, to take up his duties as a professor.

Shortly after, Regius penned a letter to René Descartes, whom he had never met but who was then living in the village of Santpoort, forty miles away (for most of his career Descartes lived in the Dutch provinces, to which he was attracted by the comparatively greater atmosphere of intellectual freedom). Regius wanted to thank Descartes, for, he said, he owed his appointment to the newly created chair in medicine to the Frenchman. Regius had read the
Discourse on the Method
when it came out the year before, including the accompanying essays on optics and meteorology, and the book had changed his world. He had previously been teaching private lessons in physics; after reading the
Discourse
he revamped his whole approach, and now his lectures were packed with students intrigued by this new way of understanding the body and, for that matter, the universe. The regents of the university took note; Regius believed that the popularity of the courses had led to his promotion.

Regius asked Descartes to accept him as his “disciple.” Descartes was delighted: he was highly susceptible to flattery, and besides that this was the type of response he needed if his work was to have an impact. Although initial sales of the
Discourse
were modest (sounding a note in harmony with authors of all eras, Descartes whined that the print run wasn't selling out, so he doubted there would be reprints), the book was being read, and he was in the process of moving from obscurity to intellectual celebrity. His name was being uttered in universities, churches, taverns, and cafés. The chattering classes of seventeenth-century Europe were writing to one another and to him using shameless superlatives, referring to him as “this great man,” “the Archimedes of our time,” “greatest of all philosophers,” and “mighty Atlas, who supports the heavenly firmament, not with raised shoulders, but by the firm reasoning of [his] magnificent mind.” The interest was in, as Regius put it, “this excellent method” that Descartes had discovered “for conducting reason in the search for all sorts of truths.”

Descartes was by now formulating his goal in life, which was nothing less than to supplant Aristotle as the basis for education. It was an almost laughably grandiose ambition, far greater than that of Galileo or Leonardo or even Aristotle himself, who after all did not think he was laying the intellectual framework for centuries of human history. Not to put too fine a point on it, Descartes wanted to reorient the way every human being thought. And he knew you didn't do that by writing a book or two and giving some lectures. If his philosophy was to be adopted he had to build a network: to win over influential professors, church officials, university overseers, and government leaders. This process would start with Regius.

Regius was keen to promote Cartesianism; with Descartes' blessing, he gave a series of formal disputations on the subject at the university. Since he was a professor of medicine, the theme was “the science of health”—a title that in itself denoted the clinical approach he would present. He seems to have built up the drama, and the audience, as he went: each talk was progressively bolder. Starting from the radical new ground of individual human consciousness, which is able to manipulate the tool of reason, he laid out the Cartesian universe in all its machinelike regularity: from the Copernican view of the heavens, in which the earth is just one of many bodies revolving around just one of many suns, to the organs of the body, which depend not on a divine agency but on the proper physical conditions for their functioning. He delved into details: the action of the pulse, respiration, and even “de excrementis.” He largely ignored theology, openly ridiculed the Aristotelian categories, and presented Harvey's theory of the circulation of the blood—which Descartes had taken up and made a central part of his own physiology—as the key to the body's functioning. (While Descartes followed Harvey's overall theory of circulation, he disagreed with Harvey's thesis that the heart pumped blood. Descartes believed—wrongly, of course—that the heart acted like a furnace that heated the blood, causing it to circulate.)