It forms no part of our story to tell how feuds between rival dynasties and rival sects of Islam, becoming more acute as time went on, enabled Christianity to recover lost ground, and, in the capture of Granada in 1492, to put an end to Moorish rule in Spain. Before that event, a knowledge of Greek philosophy had been diffused through Christendom by the translation of the works of Avicenna, Averroes, and other scholars, into Latin. That was about the middle of the twelfth century, when Aristotle, who had been translated into Arabic some three centuries earlier, also appeared in Latin dress. The detachment of any branch of knowledge from theology being a thing undreamed of, the deep reverence in which the Stagirite was held by his Arabian commentators ultimately led to his becoming “suspect” by the Christians, since that which approved itself to the followers of Mohammed must, ipso facto, be condemned by the followers of Jesus. Hence came reaction, and recourse to the Scriptures as sole guide to secular as well as sacred knowledge; recourse to a method which, as Hallam says, “had not untied a single knot, or added one unequivocal truth to the domain of philosophy.”
So far as the scanty records tell (for we may never know how much was suppressed, or fell into oblivion, under ecclesiastical frowns and threats; nor how many thinkers toiled in secret and in dread), none seemed possessed either of courage or desire to supplement the revealed word by examination into things themselves. To supplant it was not dreamed of. But, in the middle of the thirteenth century, one notable exception occurred in the person of Roger Bacon, sometimes called Friar Bacon in virtue of his belonging to the order of Franciscans. He was born in 1214 at Ilchester, in Somerset, whence he afterward removed to Oxford, and thence to Paris. That this remarkable and many-sided man, classic and Arabic scholar, mathematician, and natural philosopher, has not a more recognised place in the annals of science is strange, although it is, perhaps, partly explained by the fact that his writings were not reissued for more than three centuries after his death. He has been credited with a number of inventions, his title to which is however doubtful, although the doubt in nowise impairs the greatness of his name. He shared the current belief in alchemy, but made a number of experiments in chemistry pointing to his knowledge of the properties of the various gases, and of the components of gunpowder. If he did not invent spectacles, or the microscope and telescope, he was skilled in optics, and knew the principles on which those instruments are made, as the following extract from his Opus Majus shows: “We can place transparent bodies in such a form and position between our eyes and other objects that the rays shall be refracted and bent toward any place we please, so that we shall see the object near at hand, or at a distance, under any angle we please; and thus from an incredible distance we may read the smallest letters, and may number the smallest particles of sand, by reason of the greatness of the angle under which they appear.” He knew the “wisdom of the ancients” in the cataloguing of the stars, and suggested a reform of the calendar—following the then unknown poet-astronomer of Naishapur. But he believed in astrology, that bastard science which from remotest times had ruled the life of man, and which has no small number of votaries among ourselves to this day. Roger Bacon’s abiding title to fame rests, however, on his insistence on the necessity of experiment, and his enforcement of this precept by practice. As a mathematician he laid stress on the application of this “first of all the sciences”; indeed, as “preceding all others, and as disposing us to them.” His experiments, both from their nature and the seclusion in which they were made, laid him open to the charge of black magic, in other words, of being in league with the devil. This, in the hands of a theology thus “possessed,” became an instrument of awful torture to mankind. Roger Bacon’s denial of magic only aggravated his crime, since in ecclesiastical ears, this was tantamount to a denial of the activity, nay more, of the very existence of Satan. So, despite certain encouragement in his scientific work from an old friend who afterward became Pope Clement IV., for whose information he wrote his Opus Majus, he was, on the death of that potentate, thrown into prison, whence tradition says he emerged, after ten years, only to die.
The theories of mediæval schoolmen—a monotonous record of unprogressive ideas—need not be scheduled here, the more so as we approach the period of discoveries momentous in their ultimate effect upon opinions which now possess only the value attaching to the history of discredited conceptions of the universe. Commerce, more than scientific curiosity, gave the impetus to the discovery that the earth is a globe. Trade with the East was divided between Genoa and Venice. These cities were rivals, and the Genoese, alarmed at the growing success of the Venetians, resolved to try to reach India from the west. Their schemes were justified by reports of land indications brought by seamen who had passed through the “Pillars of Hercules” to the Atlantic. The sequel is well known. Columbus, after clerical opposition, and rebuffs from other states, “offering,” as Mr. Payne says, in his excellent History of America, “though he knew it not, the New World in exchange for three ships and provisions for twelve months,” finally secured the support of the Spanish king, and sailed from Cadiz on the 3d of August, 1492. On 11th of October he sighted the fringes of the New World, and believing that he had sailed from Spain to India, gave the name West Indies to the island-group. America itself had been discovered by roving Norsemen five hundred years before, but the fact was buried in Icelandic tradition. Following Columbus, Vasco de Gama, a Portuguese, set sail in 1497, and taking a southerly course, doubled the Cape of Good Hope. Twenty-two years later, Ferdinand Magellan started on a voyage more famous than that of Columbus, since his ambition was to sail round the world, and thus complete the chain of proof against the theory of its flatness. For “though the Church hath evermore from Holy Writ affirmed that the earth should be a widespread plain bordered by the waters, yet he comforted himself when he considered that in the eclipses of the moon the shadow cast of the earth is round; and as is the shadow, such, in like manner, is the substance.” Doubling Cape Horn through the straits that bear his name, Magellan entered the vast ocean whose calm surface caused him to call it the Pacific, and after terrible sufferings, he reached the Ladrone Islands where, either at the hands of a mutinous crew, or of savages, he was killed. His chief lieutenant, Sebastian d’Eleano, continued the voyage, and after rounding the Cape of Good Hope, brought the San Vittoria—name of happy omen—to anchor at St. Lucar, near Seville, on 7th of September, 1522. Brought, too, the story of a circumnavigated globe, and of new groups of stars never seen under northern skies.
The scene shifts, for the time being, from the earth to the heavens. The Church had barely recovered from the blow struck at her authority on matters of secular knowledge, when another dealt, and that by an ecclesiastic, Copernicus, Canon of Frauenburg, in Prussia. But before pursuing this, some reference to the revolt against the Church of Rome, which is the great event of the sixteenth century, is necessary, if only to inquire whether the movement known as the Reformation justified its name as freeing the intellect from theological thraldom. Far-reaching as were the areas which it covered and the effects which it wrought, its quarrel with the Church of Rome was not because of that Church’s attitude toward freedom of thought. On the Continent it was a protest of nobler minds against the corruptions fostered by the Papacy; in England, it was personal and political in origin, securing popular support by its anti-sacerdotal character, and its appeal to national irritation against foreign control. But, both here and abroad, it sought mending rather than ending; “not to vary in any jot from the faith Catholic.” It disputed the claim of the Church to be the sole interpreter of Scripture, and contended that such interpretation was the right and duty of the individual. But it would not admit the right of the individual to call in question the authority of the Bible itself: to that book alone must a man go for knowledge of things temporal as of things spiritual. So that the Reformation was but an exchange of fetters, or, as Huxley happily puts it, the scraping of a little rust off the chains which still bound the mind. “Learning perished where Luther reigned,” said Erasmus, and in proof of it we find the Reformer agreeing with his coadjutor, Melanchthon, in permitting no tampering with the written Word. Copernicus notwithstanding, they had no doubt that the earth was fixed and that sun and stars travelled round it, because the Bible said so. Peter Martyr, one of the early Lutheran converts, in his Commentary on Genesis, declared that wrong opinions about the creation as narrated in that book would render valueless all the promises of Christ. Wherein he spoke truly. As for the schoolmen, Luther called them “locusts, caterpillars, frogs, and lice.” Reason he denounced as the “arch whore” and the “devil’s bride,” Aristotle is a “prince of darkness, horrid impostor, public and professed liar, beast, and twice execrable.” Consistently enough, Luther believed vehemently in a personal devil, and in witches; “I would myself burn them,” he says, “even as it is written in the Bible that the priests stoned offenders.” To him demoniacal possession was a fact clear as noonday: idiocy, lunacy, epilepsy and all other mental and nervous disorders were due to it. Hence, a movement whose intent appeared to be the freeing of the human spirit riveted more tightly the bolts that imprisoned it; arresting the physical explanation of mental diseases and that curative treatment of them which is one of the countless services of science to suffering mankind. To Luther, the descent of Christ into hell, which modern research has shown to be a variant of an Orphic legend of the underworld, was a real event, Jesus going thither that he might conquer Satan in a hand-to-hand struggle.
Therefore, freedom of thought, as we define it, had the bitterest foe in Luther, although, in his condemnation of “works,” and his fanatical dogma of man’s “justification by faith alone,” which made him reject the Epistle of James as one “of straw,” and as unworthy of a place in the Canon, he unwittingly drove in the thin end of the rationalist wedge. The Reformers had hedged the canonical books with theories of verbal inspiration which extended even to the punctuation of the sentences. They thus rendered intelligent study of the Bible impossible, and did grievous injury to a collection of writings of vast historical value, and of abiding interest as records of man’s primitive speculations and spiritual development. But Luther’s application of the right of private judgment to the omission or addition of this or that book into a canon which had been closed by a Council of the Church, surrendered the whole position, since there was no telling where the thing might stop.
Copernicus waited full thirty years before he ventured to make his theory public. The Ptolemaic system, which assumed a fixed earth with sun, moon, and stars revolving above it, had held the field for about fourteen hundred years. It accorded with Scripture; it was adopted by the Church; and, moreover, it was confirmed by the senses, the correction of which still remains, and will long remain, a condition of intellectual advance. Little wonder is it, then, that Copernicus hesitated to broach a theory thus supported, or that, when published, it was put forth in tentative form as a possible explanation more in accord with the phenomena. A preface, presumably by a friendly hand, commended the Revolutions of the Heavenly Bodies to Pope Paul III. It urged that “as in previous times others had been allowed the privilege of feigning what circles they chose in order to explain the phenomena,” Copernicus “had conceived that he might take the liberty of trying whether, on the supposition of the earth’s motion, it was possible to find better explanations than the ancient ones of the revolutions of the celestial orbs.” A copy of the book was placed in the hands of its author only a few hours before his death on 23d of May, 1543.
This “upstart astrologer,” this “fool who wishes to reverse the entire science of astronomy,” for “sacred Scripture tells us that Joshua commanded the sun to stand still, and not the earth”—these are Luther’s words—was, therefore, beyond the grip of the Holy Inquisition. But a substitute was forthcoming. Giordano Bruno, a Dominican monk, had added to certain heterodox beliefs the heresy of Copernicanism, which he publicly taught from Oxford to Venice. For these cumulative crimes he was imprisoned and, after two years, condemned to be put to death “as mercifully as possible and without the shedding of his blood,” a Catholic euphemism for burning a man alive. The murder was committed in Rome on 17th of February, 1600.
The year 1543 marks an epoch in biology as in astronomy. As shown in the researches of Galen, an Alexandrian physician of the second century, there had been no difficulty in studying the structure of the lower animals, but, fortified both by tradition and by prejudice, the Church refused to permit dissection of the human body, and in the latter part of the thirteenth century, Boniface VIII. issued a Bull of the major excommunication against offenders. Prohibition, as usual, led to evasion, and Vesalius, Professor of Anatomy in Padua University, resorted to various devices to procure “subjects,” the bodies of criminals being easiest to obtain. The end justified the means, as he was able to correct certain errors of Galen, and to give the quietus to the old legend, based upon the myth of the creation of Eve, that man has one rib less than woman. This was among the discoveries announced in his De Corporis Humani Fabrica, published when he was only twenty-eight years of age. The book fell under the ban of the Church because Vesalius gave no support to the belief in an indestructible bone, nucleus of the resurrection body, in man. The belief had, no doubt, near relation to that of the Jews in the os sacru, and may remind us of Descartes’ fanciful location of the soul in the minute cone-like part of the brain known as the conarium, or pineal gland. On some baseless charge of attempting the dissection of a living subject, the Inquisition haled Vesalius to prison, and would have put him to death “as mercifully as possible,” but for the intervention of King Charles V. of Spain, to whom Vesalius had been physician. Returning in October, 1564, from a pilgrimage taken, presumably, as atonement for his alleged offence, he was shipwrecked on the coast of Zante, and died of exhaustion.
While the heretical character and tendencies of discoveries in astronomy and anatomy awoke active opposition from the Church, the work of men of the type of Gesner, the eminent Swiss naturalist, and of Caesalpino, professor of botany at Padua, passed unquestioned. No dogma was endangered by the classification of plants and animals. But when a couple of generations after the death of Copernicus had passed, the Inquisition found a second victim in the famous Galileo, who was born at Pisa in 1564. After spending some years in mechanical and mathematical pursuits, he began a series of observations in confirmation of the Copernican theory, of the truth of which he had been convinced in early life. With the aid of a rude telescope, made by his own hands, he discovered the satellites of Jupiter; the moon-like phases of Venus and Mars; mountains and valleys in the moon; spots on the sun’s disk; and the countless stars which composed the luminous band known as the Milky Way. Nought occurred to disturb his observations till, in a work on the Solar Spots, he explained the movements of the earth and of the heavenly bodies according to Copernicus. On the appearance of that book the authorities contented themselves with a caution to the author. But action followed his supplemental Dialogue on the Copernican and Ptolemaic Systems. Through that convenient medium which the title implies, Galileo makes the defender of the Copernican theory an easy victor, and for this he was brought before the Inquisition in 1633. After a tedious trial, and threats of “rigorous personal examination,” a euphemism for “torture,” he was, despite the plea—too specious to deceive—that he had merely put the pros and cons as between the rival theories, condemned to abjure all that he had taught. There is a story, probably fictitious, since it was first told in 1789, that when the old man rose from his knees, he muttered his conviction that the earth moves, in the words “e pur si muove.” As a sample of the arguments used by the ecclesiastics when they substituted, as rare exception, the pen for the faggot, the reasoning advanced by one Sizzi against the existence of Jupiter’s moons, may be cited. “There are seven windows given to animals in the domicile of the head, through which the air is admitted to the tabernacle of the body, viz.: two nostrils, two eyes, two ears, and one mouth. So, in the heavens, as in a macrocosm, or great world, there are two favourable stars, Jupiter and Venus; two unpropitious, Mars and Saturn; two luminaries, the sun and moon, and Mercury alone undecided and indifferent. From these and many other phenomena of Nature, which it were tedious to enumerate, we gather that the number of planets is necessarily seven. Moreover, the satellites are invisible to the naked eye, and, therefore, can exercise no influence over the earth, and would, of course, be useless; and, therefore, do not exist.”
In this brief summary of the attitude of the Church toward science, it is not possible, and if it were so, it is not needful, to refer in detail to the contributions of the more speculative philosophers, who, although they made no discoveries, advocated those methods of research and directions of inquiry which made the discoveries possible. Among these a prominent name is that of Lord Bacon, whose system of philosophy, known as the Inductive, proceeds from the collection, examination and comparison of any group of connected facts to the relation of them to some general principle. The universal is thus explained by the particular. But the inductive method was no invention of Bacon’s; wherever observation or testing of a thing preceded speculation about it, as with his greater namesake, there the Baconian system had its application. Lord Bacon, moreover, undervalued Greek science; he argued against the Copernican theory; and either knew nothing of, or ignored, Harvey’s momentous discovery of the circulation of the blood. A more illustrious name than his is that of René Descartes, a man who combined theory with observation; “one who,” in Huxley’s words, “saw that the discoveries of Galileo meant that the remotest parts of the universe were governed by mechanical laws, while those of Harvey meant that the same laws presided over the operations of that portion of the world which is nearest to us, namely, our own bodily frame.” The greatness of this man, a good Catholic, whom the Jesuits charged with Atheism, has no mean tribute in his influence on an equally remarkable man, Benedict Spinoza. Spinoza reduced the Cartesian analysis of phenomena into God, mind and matter to one phenomenon, namely, God, of whom matter and spirit, extension and thought, are but attributes. His short life fell within the longer span of Newton’s, whose strange subjection to the theological influences of his age is seen in this immortal interpreter of the laws of the universe wasting his later years on an attempt to interpret unfulfilled prophecy. These and others, as Locke, Leibnitz, Herder, and Schelling, like the great Hebrew leader, had glimpses of a goodly land which they were not themselves to enter. But, perhaps, in the roll of illustrious men to whom prevision came, none have better claim to everlasting remembrance than Immanuel Kant. For in his Theory of the Heavens, published in 1755, he anticipates that hypothesis of the origin of the present universe which, associated with the succeeding names of Laplace and Herschel, has, under corrections furnished by modern physics, common acceptance among us. Then, as shown in the following extract, Kant foresees the theory of the development of life from formless stuff to the highest types: “It is desirable to examine the great domain of organized beings by means of a methodical comparative anatomy, in order to discover whether we may not find in them something resembling a system, and that too in connection with their mode of generation, so that we may not be compelled to stop short with a mere consideration of forms as they are—which gives no insight into their generation—and need not despair of gaining a full insight into this department of Nature. The agreement of so many kinds of animals in a certain common plan of structure, which seems to be visible not only in their skeletons, but also in the arrangement of the other parts—so that a wonderfully simple typical form, by the shortening or lengthening of some parts, and by the suppression and development of others, might be able to produce an immense variety of species—gives us a ray of hope, though feeble, that here perhaps some results may be obtained, by the application of the principle of the mechanism of Nature; without which, in fact, no science can exist. This analogy of forms (in so far as they seem to have been produced in accordance with a common prototype, notwithstanding their great variety) strengthens the supposition that they have an actual blood-relationship, due to derivation from a common parent; a supposition which is arrived at by observation of the graduated approximation of one class of animals to another, beginning with the one in which the principle of purposiveness seems to be most conspicuous, namely, man, and extending down to the polyps, and from these even down to mosses and lichens, and arriving finally at raw matter, the lowest stage of Nature observable by us. From this raw matter and its forces, the whole apparatus of Nature seems to have been derived according to mechanical laws (such as those which resulted in the production of crystals); yet this apparatus, as seen in organic beings, is so incomprehensible to us, that we feel ourselves compelled to conceive for it a different principle. But it would seem that the archæologist of Nature is at liberty to regard the great Family of creatures (for as a Family we must conceive it, if the above-mentioned continuous and connected relationship has a real foundation) as having sprung from their immediate results of her earliest revolutions, judging from all the laws of their mechanisms known to or conjectured by him.”