The Story of Civilization: Volume VII: The Age of Reason Begins
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Scaliger, like his father, was vain of their family’s supposed descent from the della Scala princes of Verona, and he was acidly critical of fellow scholars; but in a forgetful moment he called Isaac Casaubon “the most learned of living men.”33 Casaubon’s career explored the uses of adversity. He was born at Geneva because his Huguenot parents had fled from France. They returned to France when he was three, and for sixteen years he lived amid the alarms and terrors of persecution. His father was absent for long periods of service in Huguenot armies; his family often hid in the hills from fanatical bands of armed Catholics; he received his first Greek lessons in a cave in the mountains of Dauphiné. At nineteen he entered the Academy of Geneva; at twenty-two he became its professor of Greek; for fifteen years he held that post through poverty and siege. He could barely live on his salary, but he skimped on food to buy books, and he comforted his scholastic loneliness with kindly letters from the great Scaliger. He issued editions of Aristotle, Pliny the Younger, and Theophrastus, which captivated the learned world not merely by textual emendations but by illuminating notes on ancient ideas and ways. In 1596, when Henry IV had eased the theological strife, Casaubon was appointed to a professorship at Montpellier. Three years later he was invited to Paris, but the university had closed its doors to non-Catholics, and Henry had to take care of him as curator of the Bibliothèque Royale, at the comfortable salary of 1,200 livres per year. The economical Sully told the scholar, “You cost the King too much, sir: your pay exceeds that of two good captains, and you are of no use to your country.”34 When the great Henry died, Isaac thought it time to accept an invitation from England. James I welcomed him as a fellow scholar and gave him a pension of £300 a year. But the French Queen Regent refused to let his books follow him, the King pestered him with disquisitions, the London wits could not forgive him for not talking English. After four years in England he gave up the battle (1614) at the age of fifty-five, and was buried in Westminster Abbey.
In that age the title of scholar was honored above that of poet or historian, for the scholar was revered as one whose patient learning preserved and clarified the wisdom and beauty hiding in ancient literature and philosophy. Scaliger, entering Leiden, was hailed like a conquering prince. Claude de Saumaise, known to the world of scholarship as Salmasius, was desired of many nations; after Casaubon’s death he was by common consent “the most learned of all who are now living” and, in general, “the miracle of the world.”35 What had he done? Born in Burgundy, educated—and converted to Calvinism—at Heidelberg, he shone forth, at the age of twenty, with a scholarly edition of two fourteenth-century writers on the controverted primacy of the popes, and, a year later, with an edition of Florus’ Epitome. Work after work followed, thirty in all, marked by all-embracing erudition. He reached his peak with a tremendous folio of nine hundred double-column pages, Exercitationes in … Solini Polyhistora (1629). Solinus, a third-century grammarian, had brought together the history, geography, ethnology, economy, fauna, and flora of all the major countries of Europe in an encyclopedic work which a later editor christened Polyhistor; upon this text Salmasius hung notes covering with cosmic erudition the whole world of Imperial Rome. Choosing among a dozen invitations, he accepted a professorship at Leiden, where he was at once made head of a brilliant faculty. All went well until Charles II of England, then an exile in Holland, engaged him to write a condemnation of Cromwell for beheading Charles I. His Defensio regia pro Carolo I appeared (November 1649) only ten months after the execution. Cromwell did not enjoy it; he hired the greatest poet in England to answer it; we shall hear of it again. Salmasius wrote a reply to Milton, but died (1653) before completing it, and Milton took the credit for killing him.
With so much learning in a few, probably eighty per cent of the people in Western Europe were still illiterate. John Comenius spent forty years seeking to improve the educational systems of Europe. Born in Moravia (1592), rising to be a bishop of the Moravian Brethren, he never lost his faith in religion as the basis and end of education; there could be no wisdom without the fear of God. Though his life was made an odyssey of tribulation by the religious hatreds of his time, he remained true to the tolerant philosophy of the Unitas Fratrum:
We are all citizens of one world, we are all of one blood. To hate a man because he was born in another country, because he speaks a different language, or because he takes a different view on this subject or that, is a great folly. Desist, I implore you, for we are all equally human…. Let us have but one end in view, the welfare of humanity; and let us put aside all selfishness in considerations of language, nationality, or religion.36
After writing half a hundred pedagogical texts, he summarized his principles in Didactica magna (1632), one of the landmarks in the history of education. First, education should be universal, regardless of sex or means: every village should have a school, every city a college, every province a university; advancement to higher education should be made possible for all who show themselves fit; the state must finance the discovery, training, and utilization of all the ability in its population. Second, education should be realistic: ideas should at every step be kept in touch with things; words in the vernacular or in a foreign language should be learned by seeing or touching or using the objects they represent; grammatical instruction should come later. Third, education should be physical as well as mental and moral; children should be trained in health and vigor through outdoor life and sports. Fourth, education should be practical: it should not stay in the prison of thought, but should be accompanied by action and practice and should prepare for the business of living. Fifth, more and more science should be taught with the advancing age of the student; schools of scientific research should be established in every city or province. Sixth, all education and knowledge should be directed to improving character and piety in the individual and order and happiness in the state.
Some progress was made. The German princes labored to establish an elementary school in every village. The principle of universal compulsory education was proclaimed by the Duke of Saxe-Weimar in 1619 for all boys and girls from six to twelve years of age,37 with a month’s vacation at harvest time, and by 1719 this system had been established throughout Germany. Secondary schools were still closed to women, but they multipled and improved. Twenty-two new universities were opened in this age.II Oxford was flourishing, as described by Casaubon in 1613; he was impressed by the remuneration and the social standing of the teachers there, as compared with their analogues on the Continent. Professors in Germany (1600) were so poorly paid that many of them sold beer and wine to eke out a living; at Jena the students caroused in taverns maintained by professors.38 Spanish universities declined after Philip II, withering under the glare of the Inquisition; meanwhile several universities were founded in Spanish America—at Lima in 1551, at Mexico City in 1553, long before the establishment of Harvard College in 1636. The prospering Dutch organized six universities in this period. When Leiden successfully resisted Spanish siege (1574), the States-General of the United Provinces invited the citizens to name their reward; they asked for a university; it was so ordered. In Catholic and Calvinist countries education was controlled by ecclesiastics; in England and Lutheran lands it was largely administered by clergymen controlled by the state. In nearly all universities except Padua teachers and students were required to accept the official religion, and academic freedom was strictly limited by both the state and the Church. Religious differences put an end to the international character of the universities; Spanish students were confined to Spain, English students no longer entered the University of Paris, and Oxford continued till 1871 to exact from every candidate for a degree assent to the Thirty-nine Articles of the Established Church. Originative thought tended to disappear from universities and to find refuge in private academies and noninstitutional studies.
So, in this age, private academies arose uncensored for study and research, especially in science. At Rome in 1603 Federigo Cesi, Marquis of Montebello, fo
unded the Accademia dei Lincei (Academy of the Lynx-eyed), which Galileo joined in 1611. Its constitution defined its aim:
The Lincean Academy desires as its members philosophers who are eager for real knowledge, and will give themselves to the study of nature, especially mathematics; at the same time it will not neglect the ornaments of elegant literature and philology, which, like graceful garnets, adorn the whole body of science. … It is not within the Lincean plan to find leisure for recitations and debates…. The Linceans will pass over in silence all political controversies and every kind of quarrels and wordy disputes.39
The academy was dissolved in 1630, but its purposes were carried on (1657) by the Accademia del Cimento (trial and proof). Soon similar societies were to be formed in England, France, and Germany, and the inspiring International of Science would lay the intellectual and technical foundations of the modern world.
III. THE TOOLS AND METHODS OF SCIENCE
First there had to be scientific instruments. The eyes could not see clearly enough, far enough, minutely enough; the flesh could not feel with requisite accuracy the pressure, warmth, and weight of things; the mind could not measure space, time, quantity, quality, density without mingling its personal equation with the facts. Microscopes were needed, telescopes, thermometers, barometers, hydrometers, better watches, finer scales. One by one they came.
In his Magia naturalis (1589) Giambattista della Porta wrote, “With a concave lens things appear smaller but plainer; with a convex lens you see them larger but less distinct; if, however, you know how to combine the two sorts properly, you will see near and far both large and clear.”40 Here was the principle of the microscope, the field glass, the opera glass, the telescope, a whole hatful of inventions, and all histology. The simple microscope, a single convex lens, had long been known. The invention that transformed biology was the compound microscope combining several converging lenses. The industry of grinding and polishing lenses was especially developed in the Netherlands—Spinoza lived and died by it. About 1590 Zacharias Janssen, a spectacle-maker of Middelburg, combined a double convex lens and a double concave lens to make the earliest known compound microscope. From that invention came modern biology and modern medicine.
A further application of these principles transformed astronomy. On October 2, 1608, another spectacle-maker of Middelburg, Hans Lippershey, presented to the States-General of the United Provinces (still at war with Spain) the description of an instrument for seeing objects at a distance. Lippershey had placed a double convex lens (the “object glass”) at the farther end of a tube, and a double concave lens (the “eyepiece”) at the nearer end. The legislators saw the military value of the invention and awarded Lippershey nine hundred florins. On October 17 another Dutchman, Jacobus Metius, stated that he had independently made a similar instrument. Hearing of these developments, Galileo made his own telescopes at Padua in 1609, which magnified to three diameters; these were the instruments with which he began to enlarge the world. In 1611 Kepler suggested that still better results could be obtained by reversing the Galilean position of the lenses, using the convex lens as the “eyepiece” and the concave lens as the object glass; and in 1613–17 the Jesuit Christoph Scheiner made an improved telescope on this plan.41
Meanwhile, on principles known to Hero of Alexandria in or before the third century A.D., Galileo had invented a thermometer (c. 1603). Into a vessel of water he placed the open end of a glass tube whose other end was an empty glass bulb, which he warmed by the touch of his hand; when he withdrew his hand the bulb cooled and water rose in the tube. Galileo’s friend Giovanni Sagredo (1613) marked off the tube into a hundred degrees.
A pupil of Galileo, Evangelista Torricelli, closed a long glass tube at one end, filled it with mercury, and stood it with its open end submerged in a dish of mercury; the mercury in the tube did not flow down into the dish. Scholastic physics explained this as due to “Nature’s abhorrence of a vacuum”; Torricelli explained it as due to the pressure of the surrounding atmosphere upon the mercury in the dish. He reasoned that this outside pressure would raise the mercury in the vessel into an empty tube freed from air; experiment proved him right. He showed that variations in the height of the mercury in the tube could be used as a measure of variations in atmospheric pressure. So in 1643 he constructed the first barometer—still the basic instrument of meteorology.
Armed with these new tools, the sciences called to mathematicians for improved methods of calculation, measurement, and notation. Napier and Bürgi, as we have seen, responded with logarithms, Oughtred with the slide rule; but a greater boon came with the decimal system. Tentative suggestions, as usual, had prepared the way. Al-Kashi of Samarkand (d. 1436) had expressed the ratio of the circumference of a circle to the diameter as 3 1415926535898 732, which is a decimal using a space instead of a point. Francesco Pellos of Nice in 1492 used a point. Simon Stevinus expounded the new system in an epochal treatise, The Decimal (1585), in which he offered to “teach with unheard-of ease how to perform all calculations … by whole numbers without fractions.” The metric system in Continental Europe carried out his ideas in the measurement of lengths, volumes, and currencies; but the circle and the clock paid tribute to Babylonian mathematics by retaining a sexagesimal division.
Gérard Desargues published in 1639 a classic treatise on conic sections. François Viète of Paris revived the languishing study of algebra by using letters for known as well as unknown quantities, and he anticipated Descartes by applying algebra to geometry. Descartes established analytical geometry in a flash of inspiration when he proposed that numbers and equations can be represented by geometrical figures and vice versa (so the progressive depreciation of currency in a course of time can be shown as a statistical graph); and that from an algebraic equation representing a geometrical figure consequences can be algebraically drawn which will prove geometrically true; algebra could therefore be used to solve difficult geometrical problems. Descartes was so charmed with his discoveries that he thought his geometry as far superior to that of his predecessors as the eloquence of Cicero was above the A B C of children.42 His analytical geometry, Cavalieri’s theory of indivisibles (1629), Kepler’s approximate squaring of the circle, and the squaring of the cycloid by Roberval, Torricelli, and Descartes all prepared Leibniz and Newton to discover calculus.
Mathematics was now the goal as well as the indispensable tool of all the sciences. Kepler observed that when the mind leaves the realm of quantity it wanders in darkness and doubt.43 “Philosophy,” said Galileo, meaning “natural philosophy,” or science,
is written in this grand book of the universe, which stands continually open to our gaze. But the book cannot be understood unless we first learn to comprehend the language and read the letters in which it is composed. It is written in the language of mathematics.44
Descartes and Spinoza longed to reduce metaphysics itself to mathematical form.
Science now began to liberate itself from the placenta of its mother, philosophy. It shrugged Aristotle from its back, turned its face from metaphysics to Nature, developed its own distinctive methods, and looked to improve the life of man on the earth. This movement belonged to the heart of the Age of Reason, but it did not put its faith in “pure reason”—reason independent of experience and experiment. Too often such reasoning had woven mythical webs. Reason, as well as tradition and authority, was now to be checked by the study and record of lowly facts; and whatever “logic” might say, science would aspire to accept only what could be quantitatively measured, mathematically expressed, and experimentally proved.
IV. SCIENCE AND MATTER
The sciences advanced in logical progression through modern history: mathematics and physics in the seventeenth century, chemistry in the eighteenth, biology in the nineteenth, psychology in the twentieth.
The great name in the physics of this period is Galileo, but many lesser heroes merit remembrance. Stevinus helped to determine the laws of the pulley and the lever; he made v
aluable studies in water pressure, the center of gravity, the parallelogram of forces, and the inclined plane; and at Delft, about 1690, he anticipated Galileo’s alleged experiment at Pisa by showing, contrary to immemorial belief, that when two like objects of however different weight are let fall together from a height they reach the ground at the same time.45 Descartes laid down quite clearly the law of inertia—that a body persists in its state of rest or in rectilinear motion unless affected by some external force. He and Gassendi anticipated the molecular theory of heat. He based his Météores (1637) on a cosmology no longer accepted, but the treatise did much to establish meteorology as a science. Torricelli (1642) extended his studies of atmospheric pressure to the mechanics of winds; these, he held, were the equalizing currents set up by local differences in the density of the air. Gassendi, that remarkable priest of all sciences, carried on experiments for measuring the speed of sound; his results gave 1,473 feet Per second. His friar friend, Marin Mersenne, repeated the experiment and reported 1,380 feet, closer to the current figure of 1,087. Mersenne, in 1636, established the whole series of overtones produced by a sounding string.
Research in optics centered on the complex problems of reflection and refraction, especially as seen in the rainbow. About 1591 Marco Antonio de Dominis, Archbishop of Spalato, composed a treatise, De radiis visus et lucis … et iride (published 1611), in which he explained the formation of the primary rainbow (the only one generally visible) as due to two refractions and one reflection of light in drops of moisture in sky or spray, and that of the secondary rainbow (an arc of colors, in reversed order, sometimes faintly seen outside the primary bow) as due to two refractions and two reflections. In 1611 Kepler’s Dioptrice studied the refraction of light by lenses; and ten years later Willebrord Snell of Leides formulated the laws of refraction with a precision that made possible a more accurate computation of the action of lenses on light and the construction of better microscopes and telescopes. Descartes applied these laws to a mechanical calculation of radiation angles in the rainbow. Explanation of the color arrangement had to wait for Newton.