Roger Bacon

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Roger Bacon (c. 1214/1220–c. 1292) was an English Franciscan friar and natural philosopher who argued, more insistently than almost anyone in his century, that knowledge of the world must rest on mathematics and on what he called scientia experimentalis — knowledge tested against observation rather than settled by authority alone. The honorific Doctor Mirabilis, the wonderful doctor, attached to him later, a figurative title rather than any degree he held; so did a reputation for sorcery he would have disowned, and did disown, in writing. Two men bear his name in memory. One is the irascible Oxford master who measured rainbows and badgered a pope about reforming the calendar. The other is the black-robed conjuror of the chapbooks, master of a talking head of brass. The distance between them is the most instructive thing about him.

The recovered Aristotle and the schools

Bacon came of age at the moment the Latin West was absorbing a flood of new books. The full corpus of Aristotle — the natural philosophy, the metaphysics, the works long unknown or forbidden — had been recovered through Arabic intermediaries and rendered into Latin, and it arrived trailing the commentaries of the Islamic philosophers who had kept it alive and extended it. The universities of the thirteenth century were rebuilding themselves around this inheritance, and the method by which they did so, scholasticism, turned every doctrine into a question to be argued, objected to, and resolved by reasoned reply. Bacon was a master of arts at Paris, and he was among the first there to lecture on the recovered Aristotle, in the years around 1240 to 1248 — reading the Physics, the Metaphysics, and lecturing too on grammar, logic, and the mathematical arts of the quadrivium. He belongs, with Thomas Aquinas and others, to the generation that decided what the Christian schools would do with the pagan philosopher now lodged at their center. Where Aquinas built a theological synthesis on Aristotle’s frame, Bacon turned the new learning toward the study of nature’s measurable powers, and grew impatient with colleagues who, he thought, mistook citation for understanding.

He read the Islamic scientists closely, and acknowledged the debt without the grudging tone that crept into his judgments of Latin contemporaries. Alhazen — the Basran polymath Ibn al-Haytham, whose Book of Optics had reduced the behavior of light and vision to geometry — was the master Bacon followed in his own work on perspective. He drew also on Avicenna, whose vast philosophical and medical encyclopedias shaped how the Latin world thought about the soul, the elements, and the structure of the cosmos, and on the optical and astronomical traditions that had passed through Arabic before reaching him. From this reading Bacon took a conviction that became the spine of his program: that vision, light, refraction, and the geometry of the rainbow could be studied with exactness, and that what holds for light holds, in principle, for the rest of nature.

Grosseteste, the Franciscans, and the discipline of the order

The other formative influence was nearer home. Robert Grosseteste, the first chancellor-scholar of Oxford and later bishop of Lincoln, had married a theology of light to a habit of measurement, and had begun translating directly from the Greek rather than relying on Arabic intermediaries. Bacon revered him, and the example of Grosseteste and the English Franciscan Adam Marsh drew Bacon, around 1256 or 1257, into the Franciscan order itself. The decision shaped the rest of his life, and not gently. The friars were a learned order — Bonaventure, Bacon’s near contemporary, was its minister general and one of the great theologians of the age — but they were also a disciplined one, and after 1260 a statute forbade the brothers to circulate writings without the approval of their superiors. For a man bursting with reform proposals and contempt for established opinion, the rule was a cage. Bacon spent years, by his own account, kept from the work he believed God had fitted him to do.

The papal commission and the great works

His escape came from an unlikely quarter. Guy de Foulques, a cardinal who had heard of Bacon’s ideas, was elected pope as Clement IV in 1265 and asked the friar to send him an account of his thought. Bacon read the request as a license to override his order’s silence, and answered with a torrent. The Opus Maius — the Greater Work, running to some eight hundred pages — was sent to Rome around 1267, followed by the Opus Minus and Opus Tertium, intended as summary and supplement. Together they are at once an encyclopedia and a manifesto. They survey the causes of human error and the remedies for it; the necessity of studying languages, Greek and Hebrew and Arabic, so that scripture and philosophy might be read in their own words; mathematics, which Bacon called the gate and key to the other sciences; optics and the geometry of vision; astronomy, astrology, and the calendar; alchemy; and moral philosophy, which he placed at the summit as the science to which all the others are servants. The whole presses a single case: that the sciences, rightly reformed and rightly taught, are not rivals to theology but its instruments, and that the Church neglects them at the peril of the faith.

Among the proposals was a correction of the calendar. Bacon judged the Julian reckoning intolerable, its accumulated error already shifting the date of Easter away from its true astronomical place, and he urged that days be struck from the count to bring it back into line. No one acted; the reform he sketched would not be carried out until the Gregorian calendar of 1582, three centuries on. The larger fate of his project was the same. Clement IV died in 1268, the grand scheme of reform found no other patron, and the Opus Maius passed into the hands of scholars rather than reformers. It would not be printed in full until 1733.

Mathematics, the testimony of the eye, and the hidden powers of nature

What Bacon argued, stripped of its scaffolding, was that two things had been neglected and must be restored to the center of learning. The first was mathematics — not as a separate discipline but as the language in which the rest of nature is written, the only path to certainty in the study of the heavens, of light, of weights and motions. The second was experience. Argument from authority, he held, can carry conviction but cannot remove doubt; only the thing itself, observed and where possible measured, settles a question. This scientia experimentalis he treated as a distinct power: it verifies the conclusions of the other sciences, discovers truths the deductive sciences cannot reach, and yields practical mastery over nature — the manufacture of devices, the prolonging of life, the foreseeing of effects.

It is here that the careful work of separating the man from the legend matters most. Bacon did not invent the experimental method, nor gunpowder, nor the telescope, whatever popular retellings have claimed. The experimental temper had older roots and many hands; gunpowder was a Chinese discovery, and the passage once read as a cipher for its formula in his Epistola is now judged either a later interpolation or a misreading, its supposed proportions useless even for a firecracker. He knew lenses and the magnifying power of curved glass, and he speculated, vividly, about instruments that might bring the distant near — but the telescope itself lay centuries ahead. His genuine novelty is subtler and more durable: the urgency with which he bound mathematics to physics, the insistence that claims be checked against the world, and the breadth of a mind that tried to see all the sciences as one architecture.

He also took astrology and alchemy seriously, as his age generally did, and as the recovery of Islamic learning had made unavoidable. To Bacon these were not the opposites of sound natural philosophy but parts of it — the study of nature’s hidden powers, the celestial influences that shape the sublunary world and the transformations latent in matter. His name became attached to a body of alchemical writing, some genuine and much of it later ascribed to him; the Epistola de secretis operibus artis et naturae circulated under his name for centuries and was edited and annotated in the sixteenth century by the English mathematician-magus John Dee. The Renaissance that prized such texts found in Bacon a congenial ancestor, and read him, not wholly wrongly, as a man who believed nature was full of operative power waiting to be understood.

The magician of folklore

The conjuror is a separate creation, and a later one. By the middle of the sixteenth century the historical friar had been overwritten by a folk figure, the wonder-worker of an anonymous prose romance, The Famous Historie of Fryer Bacon, and of Robert Greene’s Elizabethan stage comedy Friar Bacon and Friar Bungay, played around 1589. In these the friar builds, over seven years and with the help of a fiend, a head of brass that will speak the secret of walling all England round with a rampart of bronze — and that, watched over by a careless servant while Bacon sleeps, utters three words, Time is, Time was, Time is past, and shatters in flame. He raises devils, conjures and dismisses them, wins a duel of magic against a German sorcerer, and at the last repents and breaks his glass. This Bacon belongs to the same English appetite for tales of pacts and conjuration that produced Faustus on the same stage, and to the broader early-modern fascination with demonology — the lore of spirits commanded and spirits resisted that supplied the chapbooks their machinery. It is folklore, not biography. Its irony is sharp: the work that did most to fix the legend traveled under a title in which Bacon, writing of art and nature, expressly denied the reality and lawfulness of magic — de nullitate magiae, on the nullity of magic. The man who became England’s most famous wizard had argued that wizardry was a fraud, and that the marvels worth pursuing were the ones nature yields to art and reason.

The story that he was imprisoned by his order for suspect novelties belongs to the same penumbra of legend, if less floridly. It rests on a single late notice: a Franciscan chronicle compiled around 1370, some eighty years after Bacon’s death, which reports that he was condemned for certain suspected novelties. Modern scholarship finds the report thin and treats the whole episode as doubtful. Where historians grant it any weight, they tie it not to his science but to his combative temper, his sympathy with the radical-poverty wing of the Franciscans, and his attraction to the apocalyptic prophecies of Joachim of Fiore — the kind of unsettling enthusiasm an order might well wish to mute. The image of a martyr to experiment, persecuted for seeing too far, is a nineteenth-century embellishment laid over a record that does not bear it.

He is, finally, not to be confused with Francis Bacon, the Elizabethan and Jacobean Lord Chancellor (1561–1626) who likewise preached observation against inherited authority and likewise became a patron saint of the experimental sciences. The two are often conflated, an easy slip given the shared surname and the shared cause, but they are separated by three centuries and by temperament — the medieval friar reforming the schools for the sake of theology, the early-modern statesman proposing a wholesale renewal of knowledge for the relief of man’s estate.

The texts and the scholarship

The recovery of the real Bacon from the legendary one is the work of modern editing, and it remains unfinished. The Opus Maius was first given a critical edition by John Henry Bridges in three volumes (Oxford: Clarendon, 1897–1900), the foundation on which later study rests, and Englished by Robert Belle Burke as The Opus Majus of Roger Bacon (University of Pennsylvania Press, 1928). The great labor of bringing his unpublished writings into print was Robert Steele’s Opera hactenus inedita Rogeri Baconi, sixteen fascicles issued by the Clarendon Press between 1905 and 1940, which include Bacon’s edition of and commentary on the pseudo-Aristotelian Secretum secretorum, the mirror-of-princes text he revered and annotated as if it were Aristotle’s own counsel. His optics — the heart of his scientific achievement — was edited and translated by the historian of science David C. Lindberg in two Clarendon volumes: Roger Bacon’s Philosophy of Nature, containing the De multiplicatione specierum and De speculis comburentibus (1983), and Roger Bacon and the Origins of Perspectiva in the Middle Ages, the critical edition of the Perspectiva (1996).

The standard reassessment of his thought as a whole is the volume edited by Jeremiah Hackett, Roger Bacon and the Sciences: Commemorative Essays (Leiden: Brill, 1997), whose chapters work systematically through his philosophy of language, his mathematics and optics, his moral philosophy, his medicine, his alchemy and astrology, and the troubled state of his manuscripts — and which, more than any single book, drew the line between documented friar and inherited myth. Hackett’s own article in the Stanford Encyclopedia of Philosophy gives the current scholarly portrait in brief. Among popular lives, Brian Clegg’s The First Scientist (2003) is the most widely read, though its title concedes the very anachronism that the scholarship has spent a century dismantling.

What survives the dismantling is not smaller than the legend, only different. The friar who pressed his pope to fund the languages and the mathematics, who corrected the calendar three centuries early and was ignored, who copied Alhazen’s diagrams and traced the rainbow’s geometry, set down a wager that the schools of his day were not yet ready to take: that the surest road to wisdom ran not through the citation of masters but through patient measurement and the testimony of the eye. The brass head in the play speaks and breaks; the man’s real instrument was a pair of ground lenses and a conviction that nature would answer a question put to it precisely. The schools eventually agreed. They took their time.

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