HE THINKS, THEREFORE WE ARE

But this clear picture of Descartes’s primacy seems to have gotten muddied in recent years. His successors — from Locke to Hume, Montesquieu to Rousseau, Leibniz to Kant — are far more often cited by students of modernity. His predecessors Machiavelli, Montaigne, and Francis Bacon have all grown up to overtop him. Even his contemporaries Galileo and Thomas Hobbes occupy much larger places in standard histories than they used to. Insofar as college graduates emerge knowing anything much about intellectual history, they seem to think nowadays that the politics of Machiavelli and the science of Bacon are the hinges on which the door to modernity opened — with Jean Jacques Rousseau the first to step completely across the threshold.

There are reasons for this Cartesian decline. Priding himself on his work in science, Descartes made some valuable contributions to mathematics (the graphing of equations on Cartesian planes and the representation of variables with Xs and Ys derive from his work) and had some interesting if usually wrong things to say about physics. So too, in his late writings, he took up some questions in ethics, primarily in response to requests from the pious Princess Elizabeth of Bavaria. But he was fundamentally a metaphysician, and metaphysics has taken a beating in recent years — especially from philosophers. Even advances in pure scholarship have helped to diminish Descartes, as historians of philosophy demonstrated the continuity of his vocabulary with that of scholastic philosophers from centuries before.

And yet, though there are reasons for the decline of interest in Descartes, they are all ultimately mistaken. In part because of what he thought but even more because of the way in which he thought it, Descartes is modern times: No Descartes, no modernity.

When we discern modern threads tangled among the premodern in everyone from Machiavelli to Montesquieu, it is not because these thinkers are in fact moderns but because Descartes taught us how to tell the difference. He is modernity’s measure. In the order of logical explanation, metaphysics always comes before such secondary studies as science and ethics. But the significance of Descartes is not just logical but historical: All modern thought — in art, science, psychology, political theory, historical writing — is built upon his metaphysical foundations.

The autobiographical sketch through which Descartes presents his philosophy in the 1637 Discourse on Method, like the first-person account of introspection in his 1641 Meditations, owes a considerable debt to earlier writings: the story of a thinker’s growth in St. Augustine’s Confessions, the techniques of directed imagination demanded by St. Ignatius Loyola’s Spiritual Exercises (which Descartes followed at retreats during his school years at the Jesuit college of La Fleche), the authorial “I” in Montaigne’s essays. We have, however, crossed a divide, left the past irretrievably behind, when Descartes begins the third of the Meditations with the words:

I will now shut my eyes, stop my ears, and withdraw all my senses. I will eliminate from my thoughts all images of bodily things, or rather, since this is hardly possible, I will regard all such images as vacuous, false, and worthless. I will converse with myself and scrutinize myself more deeply and in this way I will attempt to achieve, little by little, a more intimate knowledge of myself.

This view of self-conversation, self-knowledge, and self-scrutiny — this is modernity.

But it is also true that today’s students who feel something alien in Descartes’s mental world — the students who find their soulmate rather in Rousseau’s Confessions — have in fact noticed something that cannot be entirely dismissed. It is not just the importance of God in Descarte’s metaphysical system that makes him seem strange, or the corrupted medieval vocabulary in which he sometimes expresses himself. Struggling to distinguish between the seventeenth century of Descartes and the eighteenth century of Rousseau, Nietzsche discerned that the difference lay in style: The intellectual world of Descartes was simultaneously “proper, exact, and free”; it was “not German,” but aristocratic and “firm in its encounter with the heart.”

It is this style, the aristocratic unself-consciousness with which Descartes undertakes his progress of self-consciousness, that is so alien. The modern world was born the day Descartes turned from the natural world of perception to treat the intellectual world as though it actually were a world — as though the mind were a field through which one could walk, picking up objects here and there and weighing them in one’s mental hand. The modern world, however, left Descartes’s style behind the day Rousseau ceased to be “firm.”

Perhaps the way to put the difference is to observe that, in their stroll through the fields of the mind, Rousseau is the amateur, drunk on the dewy, early-morning feeling of it all — far less interested in what he discovers inside himself than in the mental freedom and newness he feels while discovering it. Descartes is the professional, the naturalist with his notebooks and binoculars — the man who doesn’t care how much his feet hurt, so long as he gets an accurate count of all the species that nest in a particular meadow.

Or perhaps the way to put it is rather that Descartes is the adult, unself-consciously performing the work he does well — which happens to be thinking about himself. He initiated, however, a logic of modern self-consciousness that necessarily devolves to Rousseau, the perpetual adolescent, who has become self-conscious even of his own self-consciousness. What Descartes gave us is his move into the inner spaces of the self. What he could not give us is the sovereign innocence with which he made that move.

One technique for beginning to recapture Descarte’s style is to recover the conditions of his thought, and Genevieve Rodis-Lewis’s Descartes: His Life and Thought, first published in France in 1995 and now translated into English by Jane Marie Todd, constitutes a fine compendium of the current state of knowledge about the philosopher.

To write the life of someone who lived much before 1800 is to have to build up from too little biographical material rather than winnow down from too much, and Descartes contributed to his own mystery by hiding from his contemporaries as much of his private life as he could. In the first sentence of his earliest notebook, he writes, “Actors, taught not to let any embarrassment show on their faces, put on a mask. I will do the same. So far, I have been a spectator in this theater which is the world, but I am now about to mount the stage and I come forward masked.” Even in the published Discourse, he ascribes his youthful travels to a desire “to wander here and there in the world, attempting to be a spectator rather than an actor in all the comedies being played out there.” His first full biographer placed, around a frontispiece engraving, the Latin tag Bene vixit, bene qui latuit: “He lives well, who is well hidden.”

Rodis-Lewis’s primary concern in her straightforward account is to apply common sense to the enormous scaffolds of conjecture that have been built upon the scanty handful of facts known about the philosopher’s life. In particular, she aims to refute the critics and biographers who have used Descartes’s talk of a “mask” to deny his Christianity or impute to him secret vices — Maxime Leroy, for instance, who in 1929 attempted to tie Descartes to the seventeenth-century libertines who prudently hid behind the appearance of Christianity.

This sort of revisionism reached its peak in 1988 with Dimitri Davidenko’s Descartes le scandaleux, which portrayed the philosopher as a gambler and drunkard, the lover of both Queen Christina of Sweden and Princess Elizabeth, and a writer deeply involved with the Rosicrucians. (The Rosicrucian slander has a long history, based mostly on wrong-headed attempts to take seriously a brief parody that the young Descartes put in his notebooks.) Rodis-Lewis shows a man who was hardly perfect — short-tempered, quarrelsome, distant to all his acquaintances, and the father of an illegitimate daughter — but who continued always to struggle for moral balance and who could write Princess Elizabeth, four months before his death, that “the principal good in this life” is “advancing in the search for truth.”

The son of a lawyer and grandson of a doctor, Descartes was born in the town of La Haye near Tours on March 31, 1596. The actual status of his family remains hard to determine, in part because, though they were wealthy, they seem to have presented themselves — in an effort to obtain patents of nobility — as a once-noble family fallen on hard times. (Letters of chivalry were finally granted in 1668, eighteen years after Descartes’s death.) Certainly the money was sufficient that Descartes never had to work. In the Discourse, he admits that “my circumstances did not, thanks to God, oblige me to augment my fortune,” and in a letter he speaks of the possibility of spending ten thousand crowns to buy a judgeship for himself.

The formative fact of his early life was probably the death of his mother when Descartes was a year old. Rodis-Lewis determines that she died in delivering a stillborn younger brother, but Descartes always believed that she had died merely from the weak lungs that also plagued him his whole life and caused his most famous traits: a desire always to be warm (hence the typically Cartesian detail of having his great 1619 insight inside an overheated “stove”) and a need for ten or more hours of sleep a night (he rarely rose before noon).

After his schooling at La Fleche, Descartes obtained a license in law from the university in Poitiers. He was not to put his education to much immediate use, however. In 1618, he traveled to Holland to become a soldier, joining the army the Prince of Orange, Maurice of Nassau, was raising for the Thirty Years’ War. (His father loudly objected, correctly pointing out that since Descartes lacked sufficient standing to become a superior officer, a soldier’s career would make much less contribution than a lawyer’s to the family goal of becoming noble.)

The years from 1618 to 1620, however, proved the most intellectually significant of Descartes’s life. It was while in training camp in Breda that he met his first and perhaps only passionate friend, a young Dutch mathematician named Isaac Beeckman. And it was while traveling in 1619 to reach his second army post, under the Catholic duke Maximilian of Bavaria, that he had his famous insight into the mental structure of science near the northern border of Bavaria in the town of Neuberg (and not, Rodis-Lewis asserts, the commonly cited town of Ulm). The night after that stove-warmed vision, he had the famous “three dreams” that revealed to him his life’s work in seeking the metaphysical foundations of science and made him vow to undertake a pilgrimage to the shrine of Loreto in Italy.

Though Beeckman liked the young Frenchman and began to introduce him to the larger intellectual world, Descartes had made no great impression on anyone by the time he was twenty-five. And for the next eight years, before settling in the Netherlands, he did little but travel, first in Italy (where he probably fulfilled his vow) and then in France. He began nonetheless to receive some notice, even without publishing anything. This was due in part to his growing philosophical and scientific correspondence with Father Marin Mersenne, who was the era’s literary clearinghouse — the human equivalent of a modern intellectual magazine, keeping manuscripts, letters, and gossip in circulation among all the intellectuals of his time.

But Descartes’s growing reputation as an unpublished genius was due most of all to a well-noticed exchange in Paris that Rodis-Lewis places in November 1627. Visiting at the home of the papal nuncio, Descartes was asked to respond to a presentation by M. de Chandoux (a charming intellectual charlatan later hanged for counterfeiting). When Chandoux made the skeptical declaration that science rested only on a series of probabilities, Descartes not only demolished his claims but suggested to an overwhelmed audience of some of the most famous intellectuals in France the basic outline for what would become his own philosophical work. The influential Oratorian, Cardinal Berulle, in particular urged Descartes to commit his thought to print and began to speak widely of the new-found French prodigy.

In 1628, seeking solitude in order to write, Descartes moved to the Protestant Netherlands (where he would dwell for the next twenty-one years, visiting France only three more times), settling in a small city called Franeker where he could attend a private Catholic Mass: “I am of the religion of my nurse,” he told one Protestant friend who asked why he didn’t take the easier course and convert during his stay.

But though he found the quiet he needed to work, Descartes made two initial mistakes in his writing that delayed for nine years the philosophical statement for which Cardinal Berulle longed. The first was a failed attempt to express the metaphysical unity he perceived in the sciences, the uncompleted Rules for the Direction of the Mind, which he worked on from 1628 to 1629. The second was an attempt to present his metaphysics not systematically but ad passim in a treatise on physics entitled Le Monde, finished by 1634. This work might have given his anxious audience in France, primed by Berulle and Mersenne, some clues to his system, but Descartes suppressed it when he learned of the 1633 condemnation of Galileo by the Inquisition for teaching physical doctrines not far removed from his own.

Though this suppression is often cited as an example of his merely fearful bow to Christianity by upholders of the thesis of Descartes as the “masked” libertine, Rodis-Lewis is not convinced of his insincerity: His friend Saumaise declared at the time that he would have published Le Monde “if he were less a good Catholic.” It was during this same period, however, that Descartes sired Francine, the illegitimate daughter of a serving girl named Helene Jans. Born in 1635, the little girl died in 1640.

Finally in 1637 Descartes published the first work that would make him immortal: the Discourse on the Method of Rightly Conducting One’s Reason and Seeking the Truth in the Sciences, itself the preface to three scientific treatises on geometry, optics, and meteors. Just as Galileo had written in Italian, so Descartes composed his book in French to reach over the heads of the university faculties and appeal directly to the educated non-academics, and his French, even more than Montaigne’s, became the model for nearly all subsequent serious prose: As late as 1937, the poet Paul Valery declared that Descartes’s style of writing showed “the clearest and most visible characteristics of the French mind.” (The Discourse, however, was almost immediately translated into Latin — hence the famous formulation Cogito ergo sum.)

After the biographical opening of the Discourse — “a history or, if you prefer, a fable” — Descartes presents his four rules for right reasoning: “to accept nothing as true which I did not clearly recognize to be so”; “to divide up each of the difficulties I examine into as many parts as possible”; “to carry on my reflections in due order, beginning with the most simple”; and “to make enumerations so complete and reviews so general that I should be certain of having omitted nothing.”

The somewhat contentless quality of these long-awaited rules may deserve Leibniz’s mocking comment that they amount to little more than “Take what you need, do what you should, and you will get what you want.” But their importance lies less in their content than in the distinctly modern suggestions they make for how all reasoning ought to proceed.

This comes even clearer in the Meditations on First Philosophy, the more technical and fully developed metaphysical treatise Descartes published in Latin in 1641. Included in the text were Descartes’s replies to six sets of objections (a seventh was added in the second edition) from the Catholic theologian Caterus, Hobbes, Antoine Arnauld, Pierre Gassendi, and various others among Mersenne’s innumerable correspondents.

Well aware of the rise of skepticism in his own time, Descartes determined in the Meditations to use doubt to defeat doubt — his famous “hyperbolic” doubt that is so much more skeptical than anything the skeptics ever dreamed of. Since the senses sometimes deceive us, everything sensory must be doubted and thus rejected as knowledge. Since dreams and hallucinations occasionally present the mind with images and pictures, everything that the mind represents in images and pictures must be rejected. Since an evil genie of godlike power could cause one to think falsely that one remembered a mathematical truth, even mathematics must be rejected. Everything must be doubted — except of course for the fact that “I exist,” which even the act of doubting confirms, since I must exist to doubt it.

And with this foundation of the Cogito, Descartes in the succeeding Meditations quickly built up a considerable stock of mental truths now secure from the skeptics’ attacks. Since man thinks, he knows something of what he is: He must be a thinking thing — a res cogitans whose substance is mental rather than extended materially. And since he finds in his mind an idea of God that he is incapable of having thought up for himself, there must be a God who created this thought — like “the mark of the craftsman stamped on his work.” And since that idea of God includes certain infinite perfections, the mind can be assured — thanks to the goodness of the non-deceiving God — that even perceptions of material substances are true when the mind and senses are working properly.

The key to all of this is the new style with which Descartes begins to walk around inside his mind and make things tidy, as though it were a real space with real objects in it. The scholastically trained Caterus plaintively complained in his objections to the Meditations that he had been taught to define an idea as “the determination of an act of the intellect by means of an object.” But these things that Descartes calls ideas seem actually to be things: He handles them, as we might put it, the way other people handle stones.

Perhaps the first sure example of the new Cartesian style comes in the famous Cogito ergo sum. In the Meditations Descartes drops the “ergo” he had used in the Discourse, giving instead the formulation: “‘I am, I exist’ is necessarily true whenever I utter it or conceive it in my mind.” The effect is to emphasize what the twentieth-century logician Jaakko Hintikka (applying a term from J. L. Austin) has called the “performance” rather than the argument of the Cogito: I know clearly and distinctly that I exist not all the time but at those moments in which I pick up and examine the idea of my own existence. This is indeed how the evil genie could deceive me about mathematical reasoning. I cannot actually be mistaken about a mathematical truth that I perceive clearly and distinctly. But when I put down that truth and try to turn my attention to another, the possibility exists for making me forget what I had known just a moment before.

Once observed, this style of Descartes in treating the mind as an open space that needs only tidying appears throughout the Meditations. In the second, fourth, and fifth sets of objections, his questioners complained that Descartes is caught in a circle: He needs a benevolent God to guarantee that clear and distinct perceptions are true, but his proofs of God’s existence in the third and fifth of the Meditations already depend upon clear and distinct perceptions. This complaint, however, misses the uniqueness of Descartes’s arguments. The certainty he has found in the idea of his own existence provides a model for judging the certainty of other objects he finds as he walks about in his mind. Though they are entirely mental, his arguments for the existence of God belong much more to the class of experiential, a posteriori arguments like those of St. Thomas Aquinas than to the class of mental, a priori arguments like those of St. Anselm: Descartes experiences an idea rather than thinks it. It is not thinking that determines God, he said of the proof in the fifth Meditation, but “the existence of God that determines my thinking.”

The absoluteness of Descartes’s style shows through most clearly in his strange doctrine of the createdness of the Eternal Truths. Except in a few letters to Mersenne eleven years earlier, Descartes never mentioned the notion until it suddenly appeared in the reply to Gassendi (who had, as the great French scholar Emile Brehier puts it, “certainly never dreamed of attributing such ideas to Descartes”). But Descartes goes on to defend it, arguing that truths do not emanate from God “like rays from the sun,” but are created and depend upon the divine will.

It is a sign of the brief life of the Cartesian style that no one — not the continental rationalists Spinoza and Leibniz or the British empiricists Locke, Berkeley, and Hume — would follow Descartes in the claim. It is because mental objects are in fact genuinely like objects for Descartes — theoretically changeable, just as the physical world could have been created in a different manner — that he must insist God could have made possible such logical impossibilities as mountains without valleys, circles that are square, and two plus two equal to five.

Even as Descartes became the most famous philosopher of his time, his life in the Netherlands became increasingly difficult. As late as May 25, 1637, he wrote Mersenne to blame the delay in getting printing privileges for the Discourse in Paris on the intrigues of the now-hated Beeckman (who had died five days before). And from 1639 on, he seemed to grow increasingly quarrelsome. When Mersenne asked if he wanted to see other texts from the author of a book on geostatics, he replied, “Such paper can be put to only one use, and we have enough for that here.” The seventh set of objections, by a French Jesuit named Bourdin, was in fact quite bad, but Descartes responded to it by writing a letter to the priest’s superior to complain and then publishing the letter in the second edition of the Meditations. He became entangled, primarily through the over-enthusiasm of one of his disciples, in a lengthy and acrimonious wrangle with a Protestant theologian named Voetius that ended with the Dutch universities’ banning of Cartesian works for the sake of peace.

His Principles of Philosophy appeared in 1644 and The Passions of the Soul in 1649, but the most significant event of his final years was also the last: The importuning by Queen Christina. He had managed to decline one invitation and then, in March of 1649, avoid a boat sent under the command of an admiral to fetch him. But at last he gave in and went to Sweden in September, filled with dark premonitions. “A man who was born in the gardens of Touraine,” he wrote a friend, ought to avoid “the land of bears, between rocks and ice.”

Wintering with his weak lungs in drafty Sweden houses, compelled — a man who hated rising before noon — to meet with the queen at five each morning, forced to face a Lutheran court that hated him and suspected him of turning the thoughts of the queen toward the abdication and conversion to Catholicism that she finally performed in 1654, Descartes was doomed. “I am not in my element here,” he admitted in his last letter. He died early in the morning on February 11, 1650, at the age of fifty-four.

The actual thoughts that Descartes thought, the philosophical moves that he made, have in them an apparent logic of self-consciousness that would lead to the self-conscious adolescence and romanticism of Rousseau, the transcendental ego of Kant, and the ultimate denial of the reality of thoughts that we find among the postmodernists. And by his own logic — as the French philosopher Jean-Luc Marion pointed out in 1985 — Descartes could have arrived in his own generation at the dead ends and the detritus of our own late modern times. That he did not is attributable primarily to the arrogant unself-consciousness, the sovereign innocence, with which he undertook his work.

The early modern promise that Descartes holds out may still exist. If we are to recover that promise, we must look to recover, first of all, his style. Genevieve Rodis-Lewis’s Descartes is a small but helpful step toward that end.

J. Bottum is Books & Arts editor of THE WEEKLY STANDARD.