The Friar and the Cipher (13 page)

Although Bacon included the beginnings of Greek and Hebrew grammars in the
Opus Majus,
he did not hold himself up as a supreme linguist—there is no evidence that he had any serious knowledge of Arabic, for example, nor did he claim it. He was merely asserting that the results of a deductive or experimental process could be considered accurate only if the assumptions or source material underlying that process were accurate as well, an element of scientific methodology centuries ahead of its time.

THE FOURTH SECTION,
and by far the longest in the work, is entitled “Mathematics” and was, with the fifth section, “Optics,” the core of Bacon's program of education. Mathematics, as Bacon used the term, was far more than simply a means of determining quantity, position, or movement through the use of arithmetic, geometry, algebra, or trigonometry. It was a philosophic base, the discipline from which all others sprang. He called mathematics “the gate and the key” to knowledge “and all things of this world” and included in this section such unlikely subheadings as “Grammar” and “Philosophy.” “All categories,” he wrote, “depend on a knowledge of quantity, which mathematics treats, and therefore the whole excellence of logic depends on mathematics.” (This definition is not Platonic, as some have asserted. Bacon is speaking quite clearly of Aristotelian reasoning, not geometric elegance.)

It is easy to see how mathematics, when interpreted in this way, could oversee virtually all the other sciences—astronomy, anatomy, biology, geography, physics, chemistry, optics, agronomy, alchemy, and astrology. All the means of commerce, travel, growing food, and tending herds would also fall under the mathematical umbrella, as would the arts—painting, sculpture, poetry, and music. Seen in this light, mathematics was, Bacon believed, the greatest gift God ever gave to man.

But things had gone horribly wrong. “Neglect of this branch now for thirty or forty years has destroyed the whole system of study of the Latins,” he told the pope. This was as close as Bacon came to an outright denunciation of Albert, Thomas, and the legalists. “What is worse,” he added, invoking his fourth cause of error, “men ignorant of this do not perceive their own ignorance, and therefore do not seek a remedy.”

Much of the underlying theory in Bacon's mathematics and optics sections and a good deal of the specifics came from Grosseteste's research, which was in turn derived from theories first stated by the Greeks and the Arabs. “Very illustrious men like Robert, Bishop of Lincoln,” Bacon wrote, “and Friar Adam de Marisco [Adam Marsh] who by the power of mathematics have learned to explain the causes of all things . . . moreover, the sure proof of this matter is found in the writing of those men, as for example on impressions such as the rainbow, comets, generation of heat, investigation of localities on earth and other matters of which both theology and philosophy make use.”

The absence of original data, however, does not take away from Bacon's analyses. It was the ways in which Bacon proposed to use the data that was groundbreaking. He was not interested in theory for its own sake—that was the crime of which he was accusing the Dominicans. Bacon wanted science
applied
. He consolidated and synthesized available material more clearly and completely than had ever been done previously,
in order to use it
. The
Opus Majus
was filled with practical applications of mathematical science, some, such as the reform of the calendar, based on sound footing, others, such as the means to ward off old age, easy to discredit (although even this was based in a homeopathic approach not all that different from health food applications of the present day).

In optics, for example, he noted the possible usefulness of lenses “to old people and people with weak eyes, for they can see any letter however small if magnified enough.” Along with the written material, he sent Clement a lens to allow the pope to conduct some small experiments of his own. About twenty years after Bacon sent the
Opus Majus
to Viterbo, eyeglasses came into use in Italy.

Bacon cast his mathematical net everywhere, sometimes with great effect and insight, nowhere more than in his section on geography. Although wider travel and increased commerce had caused something of a renaissance in geography by the thirteenth century, the most important work ever written on the subject, Ptolemy's
Geography,
would remain lost to European scholars for another two centuries. Ptolemy's other great work, the
Almagest,
on astronomy, was available, at least in part. From this and the work of Aristotle and others, Bacon derived a brilliant overall construct.

He postulated a spherical earth through which, for geometric orientation, he drew three mutually perpendicular lines meeting at the center, thus creating x, y, and z axes. For geographic division, he divided the sphere into quarters with two circumferences, one around what later became the equator, and another through the poles. He then assumed that every place on earth was the apex of a cone, and used coordinates of objects in the heavens to project these apexes onto the earth, a theoretical navigator plotting by the stars. He thus became the first man since Ptolemy (although he did not know it) to advocate the use of coordinates to identify cities, rivers, mountains, and boundaries.

Bacon went further, producing a large map on which were plotted the coordinates of many of the cities of Europe. He used Toledo as a base and then created a grid to show relative distance and location of much of the known world. That does not mean he was always right. As to the unknown world, Bacon ascribed to Aristotle's erroneous assertion that “the sea between the west of Spain and the eastern edge of India is of no great extent.”

The original of Bacon's map does not survive, but a plagiarized version may have changed the course of history. Bacon's geographic theories found their way, almost verbatim—and without attribution—into a treatise entitled
Imago Mundi
by one Cardinal Pierre D'Ailly. D'Ailly's work, which was written in the early 1400s but not published until the 1480s, contained a large map exactly like the one Bacon had described in the
Opus Majus
. Sometime in the late 1480s, the
Imago Mundi
was read with great interest by an obscure Italian navigator named Christopher Columbus, who made almost nine hundred handwritten notations in the margins. The great nineteenth-century geographer Alexander von Humboldt believed that Bacon's passages about the size of the Atlantic Ocean were key to Columbus's undertaking his journey west. (There are those who claim that Columbus might not have read the work until 1494. If so, it seems odd that Columbus would take such interest in a theoretical document the veracity of which he had already tested.)

The question of whether or not he influenced Columbus aside, Bacon's use of mathematics to overlay geography revolutionized the science. He observed that at some places along a line in Egypt, no shadow was cast, while to one side of that line, shadows were cast northward, to the other side, southward. He further noted that in some of these locations, no shadow was cast twice a year (Tropics of Cancer and Capricorn). In discussing that part of the earth that is habitable, Bacon broke from Ptolemy. “I therefore insist that, though the habitable world known to Ptolemy and his followers is squeezed into a quarter of the total, far more than a quarter is, in fact, fit for habitation.”

Map from
Imago Mundi
BEINECKE RARE BOOK AND MANUSCRIPT LIBRARY, YALE UNIVERSITY

Many of these regions, Bacon went on, were not only
habitable
but
habitated
. “There is a boundless advantage in a knowledge of the places in the world for philosophy, theology, and the Church of God,” he wrote.

THE FIFTH SECTION OF THE WORK,
“Optical Science,” was Bacon's most detailed. Along with botany, optics was probably the most advanced science in the Middle Ages, and experiments with lenses was the prime field of application. Optics had been one of Grosseteste's specialties, and he had passed on his interest to Bacon. Once again, however, Grosseteste's work was largely theoretical, an extension of al-Hazen and al-Kindi. Bacon rigorously applied geometry to the study of reflection, refraction, vision, and what he called the “multiplication of forces,” which was largely a theory of how sensory information was transmitted to and from humans. “Force” was used in a much broader sense than in contemporary science. It was essentially any emanation, and included such things as the refraction of light through a convex lens and the consequent creation of heat at the focal point.

In his discussion of light, Bacon made a leap, the significance of which he may well have been unaware. Departing from Grosseteste, who believed that light traveled instantaneously, Bacon asserted that light moved at a speed, but one so swift that it was imperceptible to humans. He didn't apply this to astronomical bodies—stars, for example—apparently believing that even at great distance light's progress would be too fast to measure.

As revolutionary as the first five sections of the
Opus Majus
were, it was in the last two that Bacon's greatest contribution to scientific history appeared.

CHAPTER TWELVE

Seeing the Future:
The
Scientia Experimentalis
of
Roger Bacon

•   •   •

THE HEART OF THE
OPUS MAJUS,
the section of the work that most lifted it above that of Bacon's contemporaries, was Part Six, “Experimental Science.” To Bacon, experimentation was a distinct discipline, separate from but vital to all others, because without experiment one could never be sure of the truth. “Without experience, it is impossible to know anything completely,” he wrote. For perhaps his greatest leap of insight, Bacon employed this analogy:

For there are two modes of acquiring knowledge, namely, by reasoning and experience. Reasoning draws a conclusion, but does not make the conclusion certain, nor does it remove doubt so that the mind may rest on the intuition of truth, unless the mind discovers it by the path of experience . . . For if a man who has never seen fire should prove by adequate reasoning that fire burns and injures things and destroys them, his mind would not be satisfied thereby, nor would he avoid fire, until he placed his hand or some combustible substance in the fire, so that he might prove by experience that which reasoning taught. But when he has had actual experience of combustion his mind is made certain and rests in the full light of truth.
Therefore reasoning does not suffice, but experience does
. (Emphasis added.)

This was the final break from classical scholasticism, and particularly the brand of pseudoscience that Bacon considered to have been so recently perpetrated by Aquinas. It was not enough to reason one's way to truth, no matter how sophisticated the argument. Reason followed experiment, not the other way around. “Hence in the first place there should be readiness to believe, until in the second place experiment follows, so that in the third reasoning may function,” he wrote. This is the first clear statement in Christian Europe of what the modern world recognizes as hypothesis-experiment-conclusion.

To demonstrate how experimental science worked, Bacon enunciated what was probably the first rigorous, step-by-step description of scientific method ever put on paper. He did this by use of an example, laying out a series of experiments to discover the exact nature of a rainbow.

The rainbow had enormous significance in the Middle Ages. Rainbows, like thunder, lightning, and other natural phenomena, had been objects of fascination since Neolithic times. They were mentioned specifically in scripture as the reminder of a promise that God made to Noah after the flood never to repeat such a cataclysm. Genesis 9:8–16 reads:

And God said, “This is the sign of the covenant I am making between me and you and every living creature with you, a covenant for all generations to come: I have set my rainbow in the clouds, and it will be the sign of the covenant between me and the earth. Whenever I bring clouds over the earth and the rainbow appears in the clouds, I will remember my covenant between me and you and all living creatures of every kind. Never again will the waters become a flood to destroy all life. Whenever the rainbow appears in the clouds, I will see it and remember the everlasting covenant between God and all living creatures of every kind on the earth.”

It was thus generally believed that only God could make a rainbow. It was permissible to try to deduce the nature of the phenomenon, but only with the proviso that it was divinely created. That the rainbow effect manifested itself in a variety of different circumstances—water dripping off a raised oar, light passing through a hexagonal crystal, or drops of dew on grass in the morning—only served to increase the wonder of God's presence. As a result, uncovering the nature and causes of the rainbow had become one of the preeminent scientific problems of the day, akin to modern astrophysicists trying to understand the makeup of black holes.

Bacon began with a history of rainbow theory. Aristotle, who had not been limited by the assumption of divine cause, had described a rainbow as the base of a cone in which the sun was the apex and the axis (center line) passed through the eye of the beholder to the center of the base. He believed that light reflected off individual raindrops, with colors created by different combinations of bright and dark. Both Avicenna and Averroës had discussed rainbows as well, and by the thirteenth century there was general agreement that two substances of different densities (air and water, for example) must be involved in order to create the combinations necessary to produce a spectrum.

Grosseteste had accepted the Aristotelian conical construct but claimed that rainbows were caused by refraction, with reds appearing in places where the rays were most concentrated and blues where the concentration was less, the differences being caused mostly by cloud density. Albertus Magnus had agreed that refraction was the cause but believed that light was refracted in individual raindrops, then projected onto solid material in clouds. The variety of colors, Albert asserted, was due to the difference in the density of the cloud.

From this base, Bacon then used the method he had just laid out to produce a huge advancement on anything that had come before. He returned to Aristotle's notion of reflection, theorizing that refraction was impossible since an axis
always
existed between the center of the rainbow, the observer's eye, and the sun, regardless of any movement by the observer. Then he measured the height of a rainbow when the sun was at the horizon at 42 degrees, noted that as the sun rose in the sky, the rainbow receded, and concluded that when the sun is higher than 42 degrees, it was impossible for a rainbow to appear. Then, based on the observation that people in different locations all see a rainbow if conditions were favorable, he deduced that it was reflection off a myriad of raindrops that produced the effect, not off any individual one.

Bacon used only the most primitive instruments for his experiments, and some of his deductions were incorrect. For one thing, a rainbow is formed by a combination of reflection and refraction (two refractions, actually). His own contributions, the maximum angle of the sun to the horizon and the role of a myriad of raindrops, were advances in the theory but not, obviously, the final word.
*4
But Bacon never pretended to have the complete and accurate explanation.

Unlike his predecessors, particularly the Dominicans against whom he was struggling, his paramount assertion was that experimentation should be an ongoing process, that the search for truth does not end when one finds a convenient explanation that fits a predetermined conclusion. His aim, as he told the pope, was not to set forth the final truth of the matter—to achieve that, he insisted, further experimentation was needed—but rather to demonstrate method and plead for its inclusion in the curriculum.

He wrote to Clement:

Reasoning does not attest these matters, but experiments on a large scale made with instruments and by various necessary means are required. Therefore no discussion can give an adequate explanation in these matters, for the whole subject is dependent on experiment. For this reason I do not think that in this matter I have grasped the whole truth, because I have not yet made all the experiments that are necessary, and because in this work I am proceeding by the method of persuasion and of demonstration of what is required in the study of science, and not by the method of compiling what has been written on the subject. Therefore it does not devolve on me to give at this time an attestation possible for me, but to treat the subject in the form of a plea for the study of science.

Use of this method would open up vast new areas of knowledge. Bacon outlined this process in the “three prerogatives of experimental science.” They were 1) experimental science confirms conclusions to which other scientific methods already point; 2) it reaches results that take their place in existing sciences but are entirely new; and 3) it creates new departments of science.

Here is the starkest contrast between Thomas Aquinas and Roger Bacon. Once all the questions of the extent of Bacon's actual knowledge or contribution to science and Aquinas's fundamental motivation or the soundness of his logic are cut away, this simple difference is left: Roger Bacon wanted working hypotheses to be subjected to experiment, experience, and revision, and Thomas Aquinas insisted that arguments be accepted in the abstract and on faith—in every sense of the word.

Bacon entreated Clement to apply scientific method to the production of better instruments so that observation and experimentation might proceed at a faster pace. There were immediate practical benefits to this plan. Experiments with plants, herbs, and natural substances would yield remedies that could ward off disease and extend life, and would also yield better tools and weapons. If the forces antagonistic to Christ employed experimentation first and thus created better weapons sooner, it could spell disaster for the Church.

BACON REAFFIRMED HIS COMMITMENT TO REVELATION
and faith in the final section of the
Opus Majus,
“Moral Philosophy.” He saw the quest for truth in science as a deeply religious act, without which there could be no genuine triumph of God. The increased knowledge gained by experiment would only serve to prove the primacy of the scriptures and discredit those who would question God's word as revealed in the Bible. It was the legalistic approach of Aquinas, denying the truth of experiment, that was a threat to God and the Church.

Moral philosophy was therefore the highest of the sciences, that to which the proper exercise of the other sciences led. Experiment, as a prerequisite to moral philosophy, would not cause man to turn away from God and faith but rather to embrace them more fully. “[Moral philosophy] in the first place teaches us to lay down the laws of and obligations of life; in the second place it teaches that these are to be believed and approved, and that men are urged to act and live according to those laws.”

If the Church had adopted this view, it would have freed Christianity to be the leader in scientific inquiry without sacrificing the faith of revelation. It would have allowed the Church to promote the search for empirical knowledge within a code of scientific ethics that would have preserved the fundamental beliefs in Christ and scripture that it held dear. While certainly, as knowledge advanced, some of the literal interpretations of scripture-as-science would have come into question (as indeed they have today), the issues could have been resolved under ecclesiastic mandate. The Church, in refusing to accept this position, did not prevent scientific advancement—although it was postponed for three centuries—it merely assured that when science did regain its momentum it would be as adversary to Christianity, not partner.

THE MANUSCRIPT BROKE OFF ABRUPTLY
in Part Seven. Bacon had mentioned that he intended to include a section on civil law at the end, which would have made perfect sense as a closing argument. Perhaps he ran out of time and felt the need to dispatch the manuscript to Viterbo. Perhaps he completed the section but could not have it transcribed. What is known is that even before he dispatched the
Opus Majus
to the pope he decided that perhaps it was too long or too complex and began work on a shorter version, which he called the
Opus Minus
. Later he completed yet a third version, the
Opus Tertium,
which was probably intended as a supplement. In the
Opus Tertium,
in addition to an overview of his scientific arguments, Bacon included a good bit of biographical information and social commentary. It is from this document, which was never sent to Clement, that we get much of what we know of Bacon's life and circumstances.

What Bacon did send to the pope was not simply the
Opus Majus
and the
Opus Minus,
but also an additional work,
De Multiplicatione Specierum (On the Multiplication of Species)
. Although Bacon used
species
largely synonymously with
forces,
this was a far more technical treatment of multiplication of forces than that in the
Opus Majus
and was evidently included to give Clement an example of what might actually be taught in the universities. Bacon here provided more detail on his theory of perception, awareness, and how images were transmitted not only to the eye but to the brain—or the soul—as well.

To complete the package, Bacon bundled everything into the arms of his prize student, a boy known only as John, a living example of his methods:

The boy present, who in the midst of great poverty and with little instruction by devoting scarcely a year to increasing his knowledge has so widened his field that all are surprised who know him. For I say fearlessly that although some may know more about philosophy and languages, and many may excel him in various ways, yet there are none among the Latins who surpass him in every respect, and he is a match for all of them in some things; in some points he excels them. There is no one among the Latins but may listen with profit to this boy. No one so learned, that this boy may not be indispensable in many ways. For although he has learned all that he knows by my counsel, direction, and help, and I have taught him much by written and spoken word, nevertheless he surpasses me, old man though I am, in many ways, because he has been given better roots than I, from which he may expect flowers and wholesome fruits which I shall never attain.

And so, in mid-1268, John set off for Viterbo.

Centuries later, in a backlash precipitated by the cult of personality that grew up steadily around Bacon's memory, and particularly by the assertion that he was a man ahead of his time, some scholars chose to deprecate the magnitude of Bacon's achievement with the
Opus Majus
. They pointed out that the manuscript was riddled with factual errors and inaccuracies and that Bacon subscribed to superstition, attributing magical powers to astrological bodies, for example. They observed that there was a paucity of original research and that much of his work was derivative, merely an extrapolation of the thinking of men like Robert Grosseteste and Peter Peregrinus. They argued that when Bacon used the terms “experiment,” “experience,” and “mathematics,” he did not do so in the modern sense but in a narrowly medieval context. They said, moreover, that he was unduly critical of his contemporaries, particularly Albertus Magnus, who was, after all, as interested in the natural sciences as was Bacon himself. They claimed he was jealous and bitter, particularly of those scholars with advanced theological degrees from Paris, who had justifiably gained the worldwide respect and repute that Bacon himself craved, and that this colored his judgment and biased his conclusions.