THE RISE OF SCIENCE
Only the educated are free.
—EPICTETUS, FIRST CENTURY AD
Works, not Words;
Things, not Thinking…
Operation, not merely Speculation.
—CHEMIST GEORGE THOMPSON, 1660s
Prior to the rise of science there were, as Aristotle noted, only two valid ways to evaluate the merit of an idea—by critiquing its internal logic, or by comparing it to other ideas. Science offered a third option, that of testing ideas through controlled experimentation. A telling experiment might put an end to disputation, by obtaining answers directly from nature.
The conducting of scientific experiments takes time, money, and (since most experiments fail) perseverance. To support it requires of society a degree of affluence plus an appetite for innovation and change. These conditions most often arose where states vigorously competed against one another through trade, which created wealth and promoted technological and financial innovation. Scientific experimentation should therefore be expected to have first appeared in a region that combined diversity and competition, even to the point of strife, with a geography favorable to trade—a region of long coastlines, natural seaports, and proximity to foreign lands from which its people acquired a taste for the exotic and the unfamiliar. The European region that best fit those criteria was Italy.
The Italian Renaissance, generally dated from the 1400s, was kick-started by the fall of Greece and the rest of Byzantium to the Turks in 1453, an upheaval which sent thousands of Byzantine art treasures and books—notably ancient Greek and Latin manuscripts—westward by ship to the markets of the Italian peninsula. Italy was not yet a nation but a set of city-states, renowned for their vitality and their enthusiasm for liberty and independence. In Ferrara it was being said as early as 1177 that “our liberty, which we have inherited from our forefathers, we can under no circumstances relinquish, except with life itself.” The watchwords of Florence—whose celebrated poet Dante Alighieri called freedom “God’s most precious gift to human nature”—were libertas and libertà. These stirring slogans meant that citizens (a small minority of the population) had certain legal rights, and that each city-state asserted a right to govern itself rather than to be dominated by the Spanish, the French, or any other distant power. Although no Italian city-state would be called a democracy by modern standards, the circumstances within and among them produced a profusion of social experimentation, with one city-state after another oscillating between republicanism, limited democracy, and reversions to various authoritarian forms of government. Pisa, Milan, Arezzo, Lucca, Bologna, and Siena were all at some point governed by elected officials, while Florence flirted with republicanism and Venice tried various parliaments and councils to sufficient effect that William Wordsworth, ruefully surveying the fall of the Venetian Republic to Napoleon in 1797, called her “the eldest child of liberty.” Innovation and trade created new wealth and propelled merchants and artisans into the ranks of the aristocracy. This economic mobility lent a meritocratic cast to even the Kingdom of Naples—of which the prominent seventeenth-century attorney and amateur scientist Francesco D’Andrea declared, “There is no city in the world where merit is more recognized and where a man who has no other asset than his own worth can rise to high office and great wealth…without having to depend on either birth or money to get there.” Amid such social tumult, the scions of old wealth took care to at least outwardly observe an “equality of aristocrats” that embraced the newly wealthy on equal terms; even the Doge of Venice found it advisable to dress like a merchant and be bowed to only in private. The author and libertine Giacomo Casanova, whose personal preferences ran to luxury, was amused by the egalitarian appearance affected by the Venetian nobles but understood its utility:
It is impossible to judge of equality, whether physical or moral, except by appearances; from which it follows that the citizen who wants to avoid persecution must, if he is not like everyone else or worse, bend his every effort to appearing to be so. If he has much talent, he must hide it; if he is ambitious, he must pretend to scorn honors; if he wants to obtain anything, he must ask for nothing; if his person is handsome, he must neglect it; he must look slovenly and dress badly, his accessories must be of the plainest, he must ridicule everything foreign; he must bow awkwardly, not pride himself on being well-mannered, care little for the fine arts, conceal his good taste if he has it; not have a foreign cook; he must wear an ill-combed wig and be a little dirty.
The city-states’ vigorous competition with one another often escalated into war and rebellion. Their hardball politics was exemplified in the works of Niccolò Machiavelli, a career diplomat who negotiated the surrender of Pisa to Florence but wound up being tortured on the rack by the Medici. In his book The Prince, which he wrote upon retiring to the country after having lost one political battle too many, Machiavelli advises that “it is far safer to be feared than loved,” adding that “being unarmed…causes you to be despised” and that “a prince ought to have no other aim or thought…than war.” Small wonder that Baldassare Castiglione, in his internationally popular A Manual for Gentlemen of 1528—a book praised for its “civilizing” influence—observed that “the principal and true profession of a courtier ought to be in feats of arms.”
But Castiglione added that “the principal matter…is for a courtier to speak and write well.” To minimize crippling losses of blood and treasure, the Italian city-states did two things. First, they trained some of the world’s first professional ambassadors, nurturing staffs of political advisors to guide their leaders and advertise their civic virtues—especially “civic humanism,” the idea, prominent in liberal democracies today, that citizens should devote time to government service. Second, they promoted their ongoing competition in technology and the arts as a peaceful and profitable alternative to war.
The artists of the Italian Renaissance were often involved in such political competitions. Michelangelo’s larger-than-life sculpture David was commissioned, in 1501, to celebrate the establishment of a republican government in Florence, which had just freed itself from rule by the anti-Renaissance book burner Fra Girolamo Savonarola. Leonardo da Vinci, the original Renaissance man, secured a position in Milan by writing a long letter to the mechanically inclined Duke Lodovico Sforza that stressed his abilities as an inventor and military engineer, mentioning only in passing that he was also an artist. Leonardo was being candid: The painter of the Mona Lisa (which he never finished) did not in fact much like to paint, and was impatient with the fine arts generally. He preferred to work on plans for his many mechanical inventions—a pile driver, an automobile, a helicopter, a parachute, a diving bell, a robot, and various military defense systems. Leonardo’s penchant for experimentation extended to his artwork, sometimes with unfortunate results. His fresco Battle of Anghiari, done with a high-gloss oil technique of his own invention, reportedly failed to dry and ultimately slithered off the wall, vanishing entirely within fourteen years. His inventions ran so far ahead of existing technology that few could be built, much less tested, while he was alive. As the historian John Herman Randall Jr. remarked, Leonardo’s “thought seems always to be moving from the particularity of the painter’s experience to the universality of intellect and science, without ever quite getting there.”
In short, the Italy that created the Renaissance was a fragmented and disputatious gaggle of city-states that contended using every weapon they could lay their hands on, from daggers and cannons to frescoes and carved marble, their experimentation producing a torrent of political, artistic, and ultimately scientific creations. The Republic of Venice in the fifteenth century built the world’s best ships and was known for its fabrics, leather goods, and glass—its glassmakers tellingly if falsely advertising that their elegant goblets would shatter on contact with poison. Florence, hampered by a landlocked geography except when it controlled Pisa, created limited-liability partnerships for investment in the manufacture and trade of leather goods and wine and became an international center of banking and finance. Bologna invented hydraulically powered silk mills and operated more than a hundred of them, producing a million pounds of raw silk annually before the trade secret got out and was adopted by competitors. Milan, a major exporter of silk, velvet, wool, brocade, and military armor, impressed visiting Londoners who noted with astonishment that the Milanese sported over a thousand horse-drawn coaches elegant enough to turn heads back home. The papermakers of Genoa, expanding production to meet the growing appetites of an increasingly literate public, were operating a hundred paper mills by the end of the sixteenth century. By 1680, when Antonio Stradivari set up his violin-making shop in Cremona, the trade boom was slackening. Portuguese and Spanish navigators had opened up water routes to Asia around Africa, blunting the Italian advantage and putting Venice into decline, while in the Mediterranean the trading companies of Holland and England were offering fast maritime transport at competitive prices. Nevertheless, the skills acquired by Italian craftsmen kept them in the high-end luxury market, where their descendants continue to thrive today.
Many of the great Renaissance artists were men of common origins who resented being condescended to by aristocrats and by the scholars who aped aristocratic manners. Complained Leonardo, the illegitimate son of a liaison between a lawyer and a young lady said to have been a household servant:
I am fully aware that the fact of my not being a man of letters may cause certain presumptuous persons to think that they may with reason censure me, alleging that I am a man without learning. Foolish folk! Do they not know…that my subjects require for their exposition experience rather than the words of others?…Though I have no power to quote from authors as they have, I shall rely on a far bigger and more worthy thing—on experience, the instructress of their masters…. And if they despise me who am an inventor, how much more should they be blamed who are not inventors but trumpeters and reciters of the works of others.
Michelangelo—a brusque, muscular workman who went for months without bathing or taking off his dogskin boots, and whose conspicuously broken nose resulted from a fistfight—was similarly quick to take offense. When Leonardo made fun of him, joking with friends who were disputing some lines of Dante in front of the Palazzo di Gavina that “Michelangelo will explain it to you,” Michelangelo’s response was to question not Leonardo’s art but his technological ability: “You designed a horse to be cast in bronze and, as you could not cast it, you abandoned it from shame—and those stupid Milanese believed in you.” The peerless goldsmith Benvenuto Cellini was a hooligan who boasted in his autobiography of killing four men and of reducing wealthy noblemen to near-groveling as they vied to get him to accept their commissions. Although Cellini’s tales smack of exaggeration, they capture the frustration felt by many artists and artisans whose dexterity brought them money and recognition but inadequate social status.
The making and accounting of money helped advance quantitative modes of analysis without which science might otherwise have stalled at a merely descriptive level. Florentine bankers, Milanese merchants, and Venetian traders created important innovations such as double-entry bookkeeping—which their successors learned from Luca Pacioli’s authoritative Summa de Arithmetica, first published in Venice in 1494—while technological improvements pioneered by the Genoese, Florentine, and Venetian mints gained their coins an international reputation for reliable weight and purity. The minting of money became a subject of scientific interest, with Nicolaus Copernicus publishing a treatise on coinage in Poland in 1526 and Isaac Newton taking control of the London mint from 1699.
Once the printing press had radically reduced the cost of books, scientific and technological innovators found that there was money to be made by writing for the public, in the vernacular rather than Greek or Latin. Their popular books made an end run around the authorities, setting the stage for a dramatic confrontation between tradition and the emerging forces of innovation and creativity. It came in Italy. Its martyr was Galileo.
A born scientist, lifelong experimenter, and compelling writer, Galileo Galilei presented a triple threat to the professors and priests whose careers were invested in the proposition that everything worth knowing could be found in ancient books. (Galileo said that they studied “a world on paper,” whereas his experiments revealed “the real world.”) His iconoclasm appears to have been inherited from his father, the merchant, musician, and mathematician Vincenzio Galilei, who wrote papers disputing scholarly opinions about music that conflicted with experience. When his former teacher Gioseffo Zarlino asserted that the semitone cannot be divided into two equal parts—because to do so meant invoking an irrational number, which is to say a number that cannot be expressed as the ratio of two integers, a Christian taboo—Vincenzio countered that since any capable musician could hear such tones, a mathematical theory that denied their existence must be flawed. To test the prevailing claim that two strings of equal lengths which sound an octave apart must differ in tension by the ratio 2:1, Vincenzio suspended various weights from lyre strings and found that the ratio actually is 4:1. So the young Galileo had plenty of opportunity to see how experimentation could overturn the opinions of scholars.
Sent to study medicine at the University of Pisa, Galileo soon lost interest and resorted to tinkering on his own. When a concerned Vincenzio came down from Florence and found his son immersed in experiments that had little to do with his schoolwork, he bowed to the inevitable and let the boy come home. A period of free investigation followed, during which Galileo paid particular attention to pendulums—a natural step, given his father’s penchant for investigating music by hanging weights from strings. These experimentations eventually led to several important discoveries. One was “isochronism”—that a pendulum takes the same time to complete each swing, whether moving rapidly in a long arc or slowly in shorter arcs. (Isochronism suggested to Galileo that pendulums could be employed to make more accurate clocks, as they were from 1656, when Christiaan Huygens patented one.) Another finding opened the door onto gravitational physics. Galileo suspended pendulum bobs of differing weights from equal lengths of wire, and discovered that the light ones (made of cork) swung at almost the same rate as heavy ones (made of lead). Even when one ball was “a hundred times heavier” than the other, he reported, they swung in step. To test the matter further, he rolled balls down parallel inclined planes and got the same result: Regardless of their weight, they all rolled to the bottom at the same rate.
This seemingly minor observation had epochal implications. The Aristotelian professors taught that heavy objects fall faster than light objects, as everyday experience indicates. Owing to air resistance, coins dropped here on earth fall faster than feathers do. Galileo’s experiments minimized the effect of air resistance, allowing him to glimpse the truth—that gravity accelerates all objects at the same rate, regardless of their mass. With that, Galileo the college dropout opened a door for future scientists from Newton to Einstein and beyond.
Galileo’s lack of a degree frustrated his initial efforts to secure a teaching position—he was turned down by the universities of Siena, Bologna, and Florence—but he eventually landed a mathematics lectureship at Pisa, and then a higher-paying post at Padua. Padua was part of the free republic of Venice, and Galileo’s indifference to authority and vivid rhetorical style made him a favorite among the students there. The advancement of military technology was a priority in the Venetian republic, and Galileo soon supplemented his income by making inventions. He frequented the Venice arsenal, one of the world’s most advanced centers for the construction and outfitting of ships, and garnered a commission to study the physics of oars. He invented a compass for aiming cannons, a horse-driven water pump (patented in 1594), and a thermometer, eventually setting up a small business for the manufacture of scientific and military instruments.
In May 1609, having learned that telescopes were being fashioned in the Netherlands, Galileo began making telescopes of his own, turned them on the sky, and embarked on observations that demolished the Aristotelian universe. That model, fashioned in the fourth century BC by Aristotle and the Greek astronomer Eudoxus and refined by Claudius Ptolemy of Alexandria in the second century AD, placed the earth at the center of the universe and depicted the sun, moon, planets, and stars as waferlike discs attached to revolving crystalline spheres. The terrestrial realm had four elements—earth and water, whose gravity made them go downward, and air and fire, whose levity inclined them to rise. Everything above was made of a fifth element, ether, which obeyed a physics all its own. The first four elements could change, but ether could not: Hence the earth was dynamic and the heavens immutable. Flaws in this official cosmology had been observed in the behavior of comets, whose elliptical orbits required that they fly right through the crystalline spheres, and novae—“new” stars, which are actually old stars that explode and become bright enough to be seen for the first time with the unaided eye. When a nova appeared in 1604, Galileo gave three public lectures about it, pointing out that any new apparition in the heavens violated the Aristotelian proscription against change among the heavenly spheres. Such occasional anomalies could be explained away by learned Aristotelians in the Vatican and at the colleges, but Galileo’s telescopic observations ended the argument—or should have. The moon displayed rugged mountains, like the earth’s, only craggier, and in no way resembled an ethereal wafer. Venus displayed phases like the moon’s, indicating that it pursues an orbit around the sun, inside Earth’s orbit, just as depicted in the Copernican cosmology.
Galileo’s book presenting these observations, Sidereus Nuncius (“Messages from the Stars”), created a sensation. With the Italian city-states competing for geniuses in something like the way that its cities today vie for football stars, a newly famous Galileo could take his pick of academic appointments. But he assumed, as scientists sometimes do, that politics was simpler than science, and so made a series of political miscalculations.
His first mistake was to underestimate the value that liberalism afforded him as a citizen of the Venetian Republic. The University of Padua offered him tenure at double his previous salary, but he instead negotiated an appointment with Cosimo II, the Grand Duke of Tuscany, whom he had once tutored in mathematics—in effect bartering away his liberty for the glamour of a court position and the luxury of no longer having to teach undergraduates. “It is impossible to obtain wages from a republic, however splendid and generous it may be, without having duties attached,” he mused. “I can hope to enjoy these benefits only from an absolute ruler.” His friend Giovanni Sagredo, a career diplomat, warned Galileo about leaving a free republic for “a place where the authority of the friends of the Jesuits counts heavily”—the Jesuits having been banished from the Venetian Republic. “I have seen many cities,” Sagredo added, “and truly it seems to me that God has much favored me by letting me be born in [Venice]….
Here the freedom and the way of life of every class of persons seem to me an admirable thing, perhaps unique in the world…. Where will you find the freedom and sovereignty you enjoy in Venice? In the tempestuous sea of a court, who can avoid being…upset by the furious winds of envy?