Popular Science Monthly/Volume 13/July 1878/Civilization and Science I

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616910Popular Science Monthly Volume 13 July 1878 — Civilization and Science I1878Emil du Bois-Reymond

THE

POPULAR SCIENCE

MONTHLY.


JULY, 1878.


CIVILIZATION AND SCIENCE.[1]

By Professor EMIL DU BOIS-REYMOND,

OF THE UNIVERSITY OF BERLIN.

PART I.

I.—The Primordial Period, or Age of Unconscious Inferences.

THE relation of man to Nature primordially and of savage races in the present day is, as we know, very different from what it has been represented to be by poets and philosophers. In the delightful pictures their fancy painted there was nothing true: the idyllic conditions amid which they fancied the still youthful human race as living never have existed anywhere. The history of man the world over has its beginning not in a golden age, but in an age of stone. Instead of noble shepherds and lovely shepherdesses, who, under benignant skies amid picturesque scenes, live in innocence on the produce of their flocks, decorously enjoying all the purest gifts of fortune, the reality presents to our view rude, uncouth hordes struggling against hunger, against wild beasts, against the inclemency of the seasons; buried in filth, in groveling ignorance, and brutal selfishness; their women made slaves, their old people cast out; practising cannibalism first out of necessity, and then because superstitious usage had hallowed the custom.

Into the mental state of such beings we can enter as little as into that of children. We cannot strip ourselves of the acquisitions made by the generations whose successors we are, and whose priceless hoardings of the fruits of their labor now inure to our benefit. If, as Paul Broca teaches, the mean cerebral mass of Parisians in the present day exceeds that of Parisians in the twelfth century, may we not assume our brain to have, by a process of gradual improvement, become more highly developed than the brain of the men of the stone age, 100,000 years ago? And this brain, more perfect as it is by nature, has been, at an early period of its life, subjected to innumerable unconscious influences, and, later, to the conscious influences of education, which render it in some sense incommensurable with the brain of those as yet half-brute creatures.

The instinct of causality, the questioning about the "why" of things, which we greet in our children as a precious token of their awakening human intelligence, is by some philosophers regarded as an original characteristic of man's mind. Others hold even this to be a derived faculty—that it results from the faculty of generalization. So much is certain, that, among men in a low grade of culture, the instinct of causality is satisfied with reasons for things that hardly deserve the name of reasons. Nothing, we are told by Charles Martins, strikes one so forcibly in conversing with the inhabitants of the Sahara as their lack of development in this respect. These people have no idea of "cause" or of "law" as we understand those terms. For them it is the natural, and not the supernatural, that has no existence. The French officer of engineers who sinks through the gypsum crust of the desert an artesian well, thus procuring for them the blessing of a new date-grove, is, in their eyes, not a man of superior acquirement whose eye penetrates to the interior of the earth, and who knows how to discover what there is hid, but a miracle-worker, who, albeit an infidel, is on better terms with Allah than themselves, and who, like Moses of old, strikes water from the rock.

In that stage of human progress science does not as yet exist. It is the childhood period of our race, and as such it has many points of resemblance to the childhood of the individual man. As this is par excellence the period of unconscious inferences, so it is to be admitted that such inferences, guided by experiment, have led to the invention of the first tools. These were invented, not by one man, nor at one spot upon the earth, but by many, and at points very distant from one another. Thus originated levers, rollers, wedges, and axes; clubs and spears; slings, sarbacands, lassos; bows and arrows; oars, sails, and rudders; fishing nets, lines, and hooks; finally, the use of fire, by which, as by speech, man is best distinguished from animals, and which even anatomically stamps him with the character of a soot-stained lung. Man, therefore, at an early period was unquestionably entitled to the epithet bestowed upon him by Benjamin Franklin of "the tool-making animal."

II.—The Anthropomorphic Age.

Now, whatever confronted him in the shape of a compelling power of Nature, being either beyond or adverse to his own will, and whether the same affected him favorably or unfavorably, in it, owing to a propensity deeply rooted in the human mind, he recognized the act of beings like himself, though usually hidden to his senses, whom he fancied to be free from the limitations to which he himself was subject, but who for the rest had the same emotions of love and hate, gratitude and revenge, with himself. The sum of such imaginings of a given nation at a given time we call its religion; but it might also be regarded as the personificative or anthropomorphic stage of our system of Nature. This attitude of man toward Nature is very clearly seen in Homer.

According to David Friedrich Strauss,[2] the bias of man's mind toward the personification of the forces of Nature has its root in the fact that so he hopes to win the favor of those unknown and dreaded powers. Perhaps a profounder reason could be assigned. Man originally knows no other cause of occurrences save his own will, the exercise of which is matter of direct experience, and hence it is that he refers all events back to the action of a will like his own. This explanation appears all the more probable, inasmuch as the same conception, only in a more refined form, still unconsciously pervades our theories of natural science. For undoubtedly this is the origin of the idea of Force which has done so much mischief in science, and which, despite all that we can do, is still ever creeping in.[3] We even see certain addle-brains in dead earnest entertaining the fantastic conceit that, by the aid of such anthropomorphic ideas as these, the mutual attractions of bodies across empty space can be explained. What difference is there between that Will which, according to our latest Nature-philosophers, drives the atoms together, and the gods of antiquity who animated the planets? The serpent of human knowledge has once more bitten its own tail; human science has reverted to its starting-point.

Very conclusively, as would appear at first sight, Buckle, in his "History of Civilization,"[4] from the aspects of Nature in different regions, deduces the religions there originating. He shows us India bounded on the north by the Himalayas, where Mount Everest towers to a height twice as great as that of Mont Blanc, where the Pass of Kwen-Lun leads into Thibet at an elevation equal to that of Caucasus, and where the Eiger, the Mönch, and the Jungfrau, piled on top of one another, would only fill up one of the lateral valleys. Toward the south he shows us the Indian Peninsula, with its harborless coasts, projecting into a sea that stretches uninterrupted to the pole, and which is often swept by cyclones. From the mountains to the sea streams not to be bridged over flow, passing through interminable jungles, in which wild beasts and venomous serpents threaten the life of the wayfarer at every step. According to the official returns, about 11,000 persons lose their lives annually in British India from the bites of serpents, especially the cobra de capello.[5] Failure of crops, famine, and inundations, succeed one another with lamentable regularity in Bengal. The cholera-plague has its home in the delta of the Ganges; and in the devastating Indian pestilence of Rajastan, characterized by gangrene of the lungs, Hirsch recognizes the black death of the middle ages, the Florentine pestilence described by Boccaccio, which, like cholera in our times, held its ghastly circuit through the world.

In the face of such aspects of Nature as these, asks Buckle, which are ever menacing him with annihilation, must not man feel himself small and powerless? He arrives at no conscious, reasoned conclusion, but stolidly fancies to himself certain dominant and unfriendly powers as the authors of these dire calamities. He deifies the objects of his fears, erects altars to them, and offers to them sacrifice.[6] Hence it is that Hindoo mythology teems with monstrosities. Men there live 100,000 years. The ages of the world are reckoned by units followed by sixty-three zeros. The god Siva, who constitutes with Brahma and Vishnu the Indian trinity, is a monster with three eyes, wearing a necklace of human bones and a girdle of serpents. In one hand he holds a skull; a tiger's skin is his mantle; and over his left shoulder the deadly cobra rears its head. His wife Doorga is represented as of a blue complexion, with gory hands, lolling tongue, four arms, a giant's skull in one hand, a necklace of human heads; round her waist are the hands of her victims. All Hindoo deities are in like manner characterized by some inhuman or monstrous aspect—for instance, an excess of limbs or an unnatural complexion.

Buckle thinks he finds in Central America evidences of a like influence upon man's religious ideas of the dangers of life in tropical regions. The traveler Kennan refers the Shamanism of the inhabitants of the Siberian steppe to the dismal aspects of Nature by which they are surrounded. Alone on the toondra with his herd of reindeer, watching in the glare of the northern lights the howling wolves round about, the Korak stands on guard through the polar night, and fancies himself to be beleaguered by evil spirits, whose wrath he seeks to conjure away by offering to them his dogs, or by the practice of magic arts.[7] It needs not to be told how fully the gloomy sublimity of the Eddas accords in the same sense with the aspects of Nature in Iceland, where volcanic forces are ever striving with ice for the upper hand.

As contrasting with these aspects of Nature and the religions which owe to them their origin, Buckle points to the tamer and more pleasing scenery of Greece, and thence would infer the humanly beautiful character of the Hellenic mythology. With its multitudinous promontories, forming landlocked harbors, and itself surrounded by a number of beauteous islands, Hellas rises out of the Mediterranean, bearing

not a single peak covered with everlasting snow; it has no great streams, volcanoes, or deserts, and so healthful is its climate that during 1.000 years it was visited only by one great epidemic—the plague described by Thucydides. Here, says Buckle, man did not feel himself overpowered by Nature. Here it was possible for those myths to have their rise which still delight us with their undying charm, and this because, instead of personifying the destroying forces of Nature, they rather glorify whatever is purely human. True, even Grecian mythology is haunted by many monstrous shapes, which, though an abomination to the eye of the comparative anatomist, even yet in some measure disfigure the imaginations of our artists. Yet even against the worst of these monsters man could hold his own, as Ulysses against Scylla; often he triumphs over them, as Bellerophon over the Chimæra, Theseus over the Minotaur; and, by insensible gradations, ending in the pleasing personifications of the spirits of tree, and mountain, and spring, these creatures of the artistic imagination of the Greeks at last become perfectly human figures.

It is an easy thing to carry still further these ideas of Buckle's—which have also been put forward by Lecky—and to deduce the monotheism of the Semites from their inhabiting a desert region, where Nature, in its majestic uniformity, presented itself to them lacking in color and form. It is not to be denied that in this idea of an agreement between religious forms and the aspects of Nature there is a certain degree of truth; still, like many another of Buckle's deductions, this theory bears the impress of a rather superficial rationalism. Buckle overlooks a multitude of complex intermediate facts. He makes the connection between forms of religion and the aspects of Nature far too direct. In particular, in deducing Hindoo mythology from the assumed terrifying aspects of Nature in India, he surely errs. Between the Himalayas and the Indian Ocean are thousands of square miles of fertile and now very thickly-populated country, where Nature offers nothing at all to excite the imagination in an unwonted degree. And to the originators of the Brahmanic faith what was a mountain-range which they had no occasion to cross, or an ocean which they had no occasion to navigate? Can any one suppose that, had the Jews been transplanted to the region between the Indus and the Ganges, they would have excogitated the Brahmanic, or the Koraks the Hellenic religion, had they migrated to the Peloponnesus? This brings us to a point on which neither Buckle nor Lecky has bestowed sufficient attention. If we were to maintain that the general psychological character of any given portion of the human race results from (among many other conditions) the local impressions under which they have developed, and that, again, from this psychological character, combined with many other circumstances, has come its form of religion, we should be stating with more correctness the causal connection between these two orders of phenomena.

III.—The Period of Speculative and Æsthetic Contemplation of Nature.

In the next place, from the nature of the country inhabited by the Hellenes, Buckle infers the symmetry of the Hellenic mind. Here, says he, for the first time the imagination was in some degree tempered and confined by the understanding, though without impairing its strength or diminishing its vitality; and, though originally the Greeks may have borrowed a good deal from the Egyptian priests, they were nevertheless the first people in history to look on Nature from anything like a scientific point of view, as distinguished from the point of view of anthropomorphism. Though still strongly tinged with anthropomorphism, this scientific contemplation of Nature had its origin in the teaching of the Ionian physical philosophers; and then, in the course of 250 years, it had attained such a height in Epicurus that in his doctrines we already find foreshadowed the law of the conservation of energy, on which the proud edifice of mathematical physics to-day rests. And though Epicurus could neither strictly formulate this law, nor illustrate it by an example, he nevertheless makes in favor of it an argument that is almost exactly the same as one made 2,000 years later by Leibnitz. Thus, then, with respect to the ultimate questions of philosophy, those ancient thinkers were, in fact, as well advanced, or rather as little advanced, as ourselves—a fact of no small importance for our theory of understanding.

When we contemplate the advances made in mathematics, astronomy, and acoustics, even by Thales and Pythagoras, it looks as though the instinct of causality had already reached maturity among the Mediterranean nations, and as though it was destined to lead men infallibly on to the latest results of scientific inquiry, as reached in our own times, and so on to domination of Nature resulting therefrom. Every one knows how different from all this the event really was.

Under the term Natural Science, we here mean not only the sum of our knowledge of Nature, organic and inorganic, its phenomena, its effects, and its laws, but also the conscious insight into the one method which aids in enlarging that sum of knowledge, and also the conscious application of this knowledge to the useful arts, to navigation, medicine, etc.—in short, the mastery and exploitation of Nature by man with a view to increasing his own power, comfort, and enjoyment.

Natural science in this sense was all unknown, we may say, to the Greeks and Romans. Those apparently so promising beginnings lacked persistent force. It is true that, during the 1,000 years which intervened between Thales and Pythagoras and the fall of the Roman Empire of the West, individual minds attained extraordinary heights. Aristotle and Archimedes must unquestionably be reckoned among the greatest teachers that have ever appeared. So, too, for some time a steady advance of science appeared to be insured by the labors of the Alexandrine school. But nothing so plainly exhibits the hesitating step of natural science among the ancients as the simple fact that 400 years after Aristotle's day—an interval equal to that between Roger Bacon and Newton—so uncritical a collector as Pliny could exist. The case is as if Herodotus and Tacitus had exchanged places.

The history of the human mind offers few more noteworthy phenomena than this. Here are nations whose poetry and sculpture still afford us the highest delight; who, in metaphysics, history, and the science of law, produced works which, both in form and in substance, constitute the models for all ages; who to this day are our instructors in oratory, the art of war, government, and jurisprudence; but who, in their knowledge of Nature, never advanced beyond the puerile stage of credulity, and in which they rested content with the broaching of futile hypotheses. Their minds, ever ready, Icarus-like, to essay flights into the region of supersensual speculation, lacked the painstaking assiduity required to ascend the difficult path of induction—the only safe path—from particular and sharply-circumscribed facts, up to general propositions, thus rising gradually and methodically from the apparently accidental to the conception of law. True, the germ of the inductive process appears in Socrates and Aristotle; still the method which in general and theoretically was recognized as correct no one knew how to apply to particular cases; and beyond this feeble beginning nothing was done by the ancients. Even when by chance they observed aright, their very first attempt at an explanation would involve them in a tangle of such absurd and ridiculous fancies that one much prefers the theory of old Pan with his train of golden-haired nymphs ruling forest and field; of Poseidon with his trident agitating and again calming the sea; of Zeus hurling his thunderbolts. The picture drawn by Prometheus Bound of his services to humanity is a true representation of ancient science, when with astronomy, arithmetic, the alphabet, breeding of animals, navigation, mining, and medicine, he directly couples as equally important gifts the interpretation of dreams, of the flight of birds, and of the signs found in the entrails of immolated animals.[8]

In his very instructive rectorate address on "The Backwardness of the Ancients in Natural Science,"[9] Herr von Littrow deduces, from Plutarch's dialogue on "The Man in the Moon," a striking evidence of the inability of the ancients to reason scientifically. He might have quoted to the same effect Plato's "Timæus," a work abounding in intolerable absurdities; or the whole of a treatise that has come down to us bearing the name of Plutarch as its author, and entitled "Opinions of the Philosophers,"[10] of which Biot affirms that it contains the germs of all modern discoveries, nay, those discoveries themselves. Unfortunately, however, he observes, truth and error are here both equally the work of chance; the opinions here stated are like lottery-tickets, whose value is known only after the drawing.

But it is further shown by Littrow—and this is a point to which less attention had been directed—that the ancients were incapable even of observing scientifically.

That the eye must be trained, we know from physiology. The vast majority of mankind have no suspicion that we constantly see double images, but that we very properly disregard them. But few persons note the subsequent images remaining in the eye after having looked on an object, the opacity of the visual media, occurring even in the state of perfect health, or the hallucinations that precede sleep. It was only two hundred years ago discovered by Mariotte, that in each eye we have a blind spot, over which we throw the ground-color of the object contemplated, thus giving to this blank in the field of vision its most probable interpretation. From the year 1809, when Malus discovered the polarization of light, observers like Arago, Biot, Fresnel, and Brewster, had vainly endeavored with the naked eye to distinguish polarized from ordinary light. But since 1844, when Haidinger succeeded in doing this, the yellow tufts which bear his name belong, for every trained eye, to the normal aspect of the blue sky.

In the domain of tone-sensations, the harmonic notes, as we know, at first evade our immediate perception, though the timbre they give to the sound is at once noticed by every one, except those portions of the German race whose vocalization is faulty.

With such minutiæ as these, however, we are not here concerned, but with such striking objects as the stars, for the observation of which the ancients, under their favoring skies, had far better opportunity than ourselves; and which, furthermore, were to them of the greatest practical importance, both on land and sea, before the discovery of the mariner's compass. Yet the elder Pliny states the number of observed stars, i. e., of the stars according to him visible to the naked eye, as only 1,600; while Argelander reckoned 3,256; and Heis, to whom the stars appeared as points without rays, added to the last figure 2,000 more. To all this add the fact that the ancients, owing to their living in lower latitudes, could survey a larger portion of the celestial sphere than we can [in Germany]. The stars noted by the ancients decrease in number as they rise in the order of magnitudes, though, in fact, each successive class of magnitudes embraces more stars than all the preceding classes taken together. Of nebulæ and star-clusters, five were known to Ptolemy; Argelander saw nineteen with the naked eye. Hipparchus and Ptolemy take no note of the nebula in Orion, or of that in Andromeda. But the most striking circumstance of all, perhaps, is the fact that the ancients did not count the Pleiades correctly, though their number was matter of dispute, and hence an object of keener observation, and though that constellation was of importance to them in determining the seasons.[11] According to Aratus, who nourished under the successors of Alexander, there are only six Pleiades, and it is a vulgar error to admit that they were seven, and that one of them was lost. Hipparchus, however, corrected Aratus, and fixed the number of the Pleiades at seven. Nevertheless, Ovid says of the Pleiades:

"Quæ septem dici, sex tamen esse solent;"[12]

—and the poets went on speaking of a lost Pleiad.[13] But nowadays ordinary observers, with good eyesight, can discern fourteen to sixteen stars in this constellation.

The ancients, then, according to Littrow, described the heavens as imperfectly as though they had been to some extent short-sighted, or as though—but this supposition is negatived by other facts—the discriminating power of the human retina had since become more acute. On the other hand, we cannot sufficiently admire the refinement of their artistic sense in reproducing the forms of the human body. In counting the Pleiades they erred. But the wavy lines of female beauty have never been rendered with greater perfection than by them; and the Borghese Gladiator gives evidence in every one of his quivering muscles of such close observation as to lead to the supposition that in the ancient art-schools there was an esoteric teaching of anatomy.[14] It is customary to attribute the supreme skill of the ancient sculptors in representing the human body to the advantages they enjoyed, as compared with our own artists, who can only study professional models, in frequently viewing the nude in unconstrained action in gymnasia and at the public games. But, with respect to the female figure, the ancient sculptors had no such great advantage over our own, and yet here, too, they have attained unequaled excellence. So, too, our artists have as fair opportunity of studying the breast of a live, nude horse as the ancients had of observing nude athletes; and yet it was said, during the lifetime of Franz Krüger, that he was the only artist who knew how to paint a horse's breast. The truth is, that the ancients had a special inclination for this kind of observation, but it lay altogether outside their habits of thought nicely to determine the limits of a phenomenon as regards space, time, and weight. Hence, in all that concerns artistic forms their eye was very highly developed, but they lacked the training needed for grasping scientific facts.

They were utter strangers to the art of experimentation, wherein methodical observation under arbitrarily determined conditions combines with a fervid inventive imagination and a calm judgment to produce a purely modern form of mental activity, which oftentimes not only leads to certitude in the experimental science, but even evokes new phenomena. Thales already was acquainted with "the soul of amber," and the power of the Heracleian Stone was well known to the ancients as a matter of simple curiosity. But they never got beyond the first crude observation of those effects out of which the modern mind has developed a whole world of facts and ideas.

In the time of Alexander the Great, however, interest in remarkable natural curiosities was so far developed that he used to send back from his expeditions such objects to his teacher Aristotle. But how little was done later by the Romans toward utilizing the unparalleled opportunities they enjoyed for increasing the knowledge of Nature! From every quarter of their immense empire they gathered animals for their vulgar shows and feasts. At enormous expense they raised all manner of animals for food. We read, too, of their aviaries. But we learn nothing of any establishment in Rome for exhibiting plants and animals—a managerie or a botanic garden—such as we find even among the Aztecs.[15]

Without scientific observation, experiment, and sound theory, no enduring progress can be made in the useful arts. Such progress necessarily depends on conscious utilization of natural forces observed in their orderly workings. Of this, on the whole, the ancients had no idea. True, they carried to a high state of perfection some few branches of useful art. In architecture, road-making, and bridge-building, in bronze-casting and the art of cutting precious stones, they were masters. The art of fortification and the siege enginery of the later Romans are truly wonderful. But, if we would estimate aright the degree of technical skill reached by the ancients, we must compare it with the results attained by other nations. The technical skill wherein they excelled belongs to a comparatively low grade of culture. In architecture, for instance, the Egyptians, too, as well as the Assyrians, the Hindoos, and even the Peruvians under the Incas, were very proficient. A much higher degree of culture is marked by the invention of the mariner's compass, gunpowder, and printing. Next comes the steam-engine, an invention which we owe to modern European civilization.

The second of these stages of technical evolution the ancients never attained. On the other hand, it was reached at a comparatively early date by the civilized peoples of Eastern Asia, who, in other respects, seem barbarous as compared with the Greeks and Romans. These Asiatics, it is true, only employed the compass on land-journeys, used gunpowder only for fireworks, and they did not in printing employ movable types, owing to the clumsiness of their mode of writing. But, even in their pottery and textile fabrics, the classic nations were surpassed by the Hindoos, the Chinese, and the Japanese. The ancient civilization always stood, so to speak, with one foot in the bronze age. To get an idea of the tardiness of their progress in the useful arts, we might compare the difference in material culture between the time of Pericles and that of Constantine on the one hand, and between Barbarossa's time and our own on the other. All industrial occupations among the ancients were, for the most part, confined to the servile class. This is the reason often assigned for the low state of industrial art among them. But may we not rather recognize, in the contempt of the freemen for industrial occupation, their small capacity for the same? However this may be, the material culture of the ancients evinces a one-sidedness and an imperfectness corresponding to the deficiencies we have already found to exist in their theoretical culture.

Hence comes the disproportion between technical and æsthetic performance, so often noticed in the products of ancient art-industry. In our museums, every one admires the candelabra brought from the villas of wealthy Romans, which were destroyed by the eruption of Vesuvius. From light bronze branches, whose leaves seem to flutter in every breath of air, are suspended by slender chains a number of beautifully-fashioned lamps. By the light of these lamps Cæsar wrote his "Commentaries," Cicero rounded his periods, Horace gave the last polish to his "Odes." Each lamp is simply an oil-holder, into which dips a wick—a smoky affair, that no scullery-girl would tolerate nowadays. The idea of discovering the source of the light given by the lamp; of finding it in a more or less perfect combustion of a combination rich in carbon—a combustion carried only so far that, in the hot but not luminous flame produced by perfect combustion, some solid carbon-particles shall be brought to a white heat; of bringing about this degree of combustion by regulating the supply of air and oil; meantime, of protecting the flame from air-currents, saving the surrounding objects from smut, and guarding the organ of smell from the offensive odors of acrolein—such thoughts never once appear to have occurred to the minds of the artists of Magna Græcia. For them, the most perfect lamp was the one that was the most ornamental. If more light was needed, other smudgy lamps were added.

Thus the ancient culture resembled one of those coins on which a master-hand had stamped a noble countenance of some deity, but which he could not make round. We may, therefore, justly characterize this civilization as being essentially aesthetic, and the attitude of the ancients toward Nature as speculative and æsthetic.

The backwardness of the ancients in natural science was fruitful in most serious consequences to the human race. It was one of the chief reasons of the downfall of the old civilization. The greatest misfortune that ever befell humanity, namely, the overrunning of the Mediterranean countries by the barbarians, could have been prevented had the ancients possessed natural science as we understand that term.

This point has not, perhaps, been sufficiently noted hitherto. When Montesquieu and Gibbon described the fall of the Roman Empire, natural science had not attained its present importance in the minds of modern nations, and even to this day it is for the most part overlooked by writers of history. The numerous causes under the action of which the Roman Empire was destined to crumble to pieces, and to become the prey of the barbarians, have been again and again set forth with much learning and skill. No doubt the ancient world had grievous internal ills. Slavery, pretorianism, corruption of morals, and aversion to matrimony, decay of civic as also of military virtue, the enervation caused by over-refinement, which had exhausted every pleasure and profaned every ideal, and which could not find in itself the means of rising above itself—such are the oft-cited causes to which the inevitable downfall of the Roman domination is ascribed.

And yet the success which almost invariably attended the efforts of vigorous emperors is proof that the state of affairs was not entirely hopeless. Down even to a very late period of the empire's history, the course of events was tolerably amenable to control and regulation, and in the face of the enemy the legions did not altogether belie their hereditary valor and discipline. Even in the palmiest days of the Roman state they had not always been victorious. The introduction of Christianity did not move the ancient world out of the ruts so much as might have been expected. Though a portion of the ancient culture was then thrown overboard, it nevertheless, on the whole, remained intact. There yet stood, under the protection of the victorious cross, temples, theatres, baths, halls of justice; the multitude of the works of art baffled the fury of the destroyers, and the papyrus rolls of the libraries still preserved unscathed the treasures which a thousand years had collected. What was needed was to oppose to the inpouring barbarian hosts from the northeast a barrier which should last until the tide had begun to ebb, and these hordes had themselves come under the influence of civilization: then all would have been well.

It was the opinion of Liebig, who also contemplated the downfall of the ancient culture from the point of view of the natural sciences, that the case was hopeless, whatever might be done. As a result of his researches on mineral manures, Liebig taught that the Roman Empire fell like the Grecian communities at an earlier day, and like the Spanish domination later, because in the countries from which the Romans derived their grain the soil had become exhausted of the mineral matters requisite for growing wheat, especially of phosphoric acid and potash.[16] This doctrine was refuted by Conrad, who shows that the fact of the soil having been exhausted is not proved. In every instance where, according to Liebig, the soil was exhausted by improvident cropping, other reasons may be assigned for the decreased fertility; for instance, drought resulting from the decay of irrigation-works, or from reckless deforestation, and the production of marshes from the want of river-levees, or the sinking of the soil by volcanic action. Many a tract of waste-land in Italy, which in former times was thickly populated, would still be productive were it not that the dragon of malaria keeps watch on the golden fleece of the grain-harvest. The south of Spain did not become barren till after Christian intolerance had driven out the industrious Moors, and Gothic laziness had permitted their irrigation-canals to become choked up. Wherever, therefore, sterility was not produced by irresistible natural agencies, it was not the cause, but rather the result, of the decay of the state. Under more favorable political conditions, the ancient fertility of the soil might be restored, but the evils of deforestation, as we see in Provence, can hardly ever be repaired.

It was not because the soil of the Mediterranean countries was impoverished in phosphoric acid and potash that the ancient civilization went to ruin, but because that civilization was built on the quicksand of aesthetics and speculativism, which was quickly swept away by the tide of barbarian invasion. Suppose the legionaries had been armed with flint-lock muskets, instead of the pilum, and that, instead of the catapult and the ballista, the Romans possessed even such artillery as was employed during the sixteenth century. Would not all the migrant hordes, from the Cimbri and the Teutones down to the Vandals, have been sent back home with broken heads? True, the Romans beat back the Teutones with the pilum alone, for, even with equal arms on both sides, the superior military science, backed by higher mental and bodily development, ever prevails over undisciplined masses of men. But, had fire-arms taken the place of the pilum, the Romans would always have triumphed over the barbarians, even without a Marius, and without such terrible efforts as at Aquas Sextiæ. It is vain to speculate in history about what would have happened under altered circumstances. So much, however, is clear, that, had not the ancients neglected to win for themselves that absolute mastery over brute force which the subjugation of Nature and the progressive improvement of industrial skill always insure, the two ethnic elements of the "Nibelungenlied," namely, Northern heroes and horsemen from the steppes of Asia, would have been powerless against the Roman Empire, though its rottenness stunk to heaven. And, had the ancients developed their inventiveness sufficiently to originate the art of printing, then, despite the invasions of the barbarians, we should not have to lament evermore the loss of so many a masterpiece of poet, orator, and historian.

IV.—The Scholastico-Ascetic Period.

But the ancient culture succumbed. The night of the middle ages settled down upon those shores of the Mediterranean once illumined with the splendor of all that is grand and beautiful. To this was added a peculiar fatality which made the intellectual ruin more complete, and entirely checked for a long time the progress of natural science which under the ancients had been tardy enough.

With the fall of Roman power came, at the same time, the fall of polytheism, a system dating from the anthropomorphic period of the Philosophy of Nature. Christianity now came into possession of Olympus, crowded with barbaric gods, and banished its denizens to the region of demons and ghosts. Nor was it content with such purification of the temple as this. Sprung itself from Judaism, which possessed neither art nor science, but which was already characterized by an exclusive estimate of the value of moral effort, the new creed restricted the circle of ideas, which alone it recognized as profitable to man, within the categories of good and bad, and the relations between the sinful creature and his creator. In opposition to heathenism, which was languishing from sensuous excess, it enjoined on its adherents self-denial and contempt of earthly life, and bade them to tremble in constant expectation of the judgment which was to come both for them and for the whole world. This earth, with all its glory, appeared henceforth to man as a resting-place unworthy of notice, where the soul must prepare for a better state to come. Our body, given to us in love by father and mother, this crown and masterpiece of creation, Christianity despised as the perishable shell of the soul which alone was akin to God; nay, it hated the body as the accursed source of sin. Only with fear and trembling could the believer pluck the fruit of the tree of life. A celibate life within the walls of a cloister, and entirely occupied with prayer and penances, was held to be the best way, and the one most pleasing to God, of spending the time of trial here below; in recompense, the elect were assured of sempiternal beatitude post mortem.

That this new mode of looking at the universe was little favorable to natural science is obvious. Still it is only with difficulty that we can form to ourselves an idea of the attitude of the human mind toward Nature during the middle ages. A passage from the life of Francesco Petrarca will serve to throw light upon this point.

Petrarca, in whom the reminiscences of classic antiquity awoke and were strangely blended with the beliefs of his own day, daily had in sight, from Avignon, Mont Ventoux, that uttermost spur of the maritime Alps, swept by the mistral. Long had he wished to stand upon its summit. His longing was stimulated on reading in Livy that Philip of Macedon (the enemy of the Romans) ascended Mount Hæmus, in Thrace,[17] in order to view simultaneously the Adriatic and the Euxine. At last, on the 26th of April, 1336, the plan was carried into execution, and, as the weather was very favorable, Petrarca and his younger brother, Gherardo, enjoyed the broad prospect. The clouds beneath his feet proved to him the possibility of what he had often read of before with incredulity with regard to Athos and Olympus. The distant chain of the Alps calls to his mind Hannibal, and beyond he descries, with the mind's (rather than the bodily) eye, the land for which he longed—Italy. But now he feels the fetters which bind him growing painfully tighter; the image of his mysterious lady below there in Avignon, and whom he had for the first time seen almost exactly nine years before, April 6, 1327, rises before his mind. Of the Ovidian verse which he uses to describe the state of his feelings—

"Odero si potero. Si non, invitus amabo"—[18]

we can hardly say that it expresses a great amount of passion. The grandeur of the surrounding spectacle, the Rhône at his feet, in the distance the flashing mirror of the Mediterranean between Marseilles and Aigues Mortes, bring him back again to the real world. While he abandons himself to these impressions, it occurs to him to open, as though it had been a "book of fate," a little copy of St. Augustine's "Confessions" which he always carried about with him. He read there this passage: "Men go to gaze on lofty mountains and the mighty waves of the sea, and the wide currents of rivers, and the vast extent of ocean, and the circling courses of the stars, and they overlook themselves."[19] Taken in connection with the context, the passage does not carry an ascetic meaning, but occurs in the course of a theoretical explanation of memory that rather does credit to the mystic Bishop of Hippo. But Petrarca sees in these words, so directly applicable to his surroundings at that moment, the very finger of God. Full of shame and remorse, and without uttering another word, he descends from the mountain, and that very night addresses to his confessor, Dionigi de' Roberti, the doleful letter from which we take this narrative. The poor fellow had for a moment, forgetful of his soul's welfare, indulged the harmless pleasure of looking out on the entrancing world of sense, when he should have been moodily contemplating his own inner state. So diseased were the intellectual faculties of man in Europe in that age, that this incident sufficed to bring a conscientious, fine-feeling, but not very strong-minded man like Petrarca into a state of intensely painful self-conflict.

Fortunately, the "Decamerone" shows that not all minds were so delicately strung. But in the "Divina Commedia" we curiously enough see a poetic imagination of the highest power, equipped with all the scientific lore of its day, clothing the ascetic view of the world in such a garb of stern reality, that King John of Saxony has been able, from the description given in the "Inferno," to sketch a topographical plan of hell, as though Virgil had conducted, not a poet, but a scientific traveler—a Leopold von Buch, for instance—through the infernal regions.

It was not only by depreciating in the estimation of mankind the world of phenomena that Christianity, during this dreary period, discouraged the study of Nature, but also by proposing to them new and peculiar aims, before unheard of. Amid a darkness of their own procuring, men busied themselves with such problems that to them might well have been addressed the reproof of Romeo to Mercutio: "Peace, peace! thou talk'st of nothing." The best minds of the time expended no end of labor and ingenuity in distinguishing between absurdity and nonsense. Like a plant in the dark, the ancient philosophy put forth colorless and weakly sprouts which sought the light mainly in two directions, platonistic tendencies finding expression in an insane gnosticism, and Aristotelian tendencies in barren scholasticism. Scholasticism held the ground longest, and the scholastico-ascetic period will always remain as a warning to show to what length the unaided human mind, divorced from the world of reality, and without the revelation of Nature, can go astray.

V.—The Rise of Modern Science.

Inasmuch as humanity recovered from this madness through the study of the ancients, revived by Petrarca and Boccaccio, the next ensuing stage of development is called the stage of humanism. In the dusty codices the mind of the Christian West, awakened as it were from a bewildering dream, got a glimpse of the grand old heathen world; and, hardly believing its own eyes, began to understand how deplorably narrow was the circle of ideas within which it had in some unaccountable way suffered itself to be confined for a thousand years. A flood of reawakened ideas coursed through school and castle and town, and even through the cloisters; and, as it might be increased, swept away the musty trumpery of mediæval hallucination. With the ideas of the ancients, their works of art, too, arose from the grave. To the newly-awakened antique spirit corresponded the new form of the beautiful; and in an instant, almost, art flourished as it never has flourished since, with a bloom which is to the bloom of Hellenic art what a flower, perhaps of less perfect form, but of heavenly sweet odor, is to a flower of perfect beauty but odorless.

This resurrection of the human mind, with its natural consequences—the reformation of the Church, and the new birth of philosophy and the other sciences of mind—has oftentimes been described at length. Still, one point has commonly been overlooked, which it is not so easy satisfactorily to deduce. As we have seen, the ancients knew nothing of natural science, in our sense of the term. Is it not, then, a very curious circumstance that the resuscitation of classical studies should have given the impulse to the development of modern natural science?—that the ancients, who themselves could not think scientifically, nor experiment, nor even observe, should now, by their teaching and by their ideas, produce a race in whom these faculties were to go on steadily and incessantly developing—a race bearing to the authors of its intellectual culture the same relation as subsists between a brood of ducks and the hen that has hatched them out? To what cause, then, do modern civilized peoples owe the victorious outburst of the instinct of causality which among the ancients found no adequate or methodical expression, or was satisfied with futile reasons? Must we say that among the Kelts and Germans, who soon vied with the Latin peoples in their ardor to share in this newly-awakened intellectual activity, this instinct was naturally stronger than among the Greeks and Romans? And was, perhaps, Keltic or Germanic blood mingled with Tuscan in the veins of the youth who, during mass, discovered the isochronism of the pendulum oscillations in Buschetto's cathedral?

The greater seclusion and introspection of northern life, the quiet and leisure of the monasteries, the exigencies of a ruder climate, are cited as conditions that would naturally dispose the modern civilized nations toward investigation of Nature and the manufacturing arts. But if we trace backward the course of modern science, we at last find many clews leading into the laboratories of the alchemists and the observatories of the astrologers; and here, as we know, we meet with Arabian philosophy as a new element of culture.

While beneath the sign of the Cross the night of barbarism was settled down on the Western world, in the East, under the green standard of the Prophet, an original form of civilization had been developed, which not only preserved what had been won by the classical peoples in mathematics, astronomy, and medicine, but even itself made no mean acquisitions in those sciences. Through the crusaders and the Spanish Moors, this civilization had in many ways reacted on Europe, and it is natural for us to seek here for the source of those new ideas which the mind of the Western nations, reawakened by the writings of the ancients, could not have drawn from those writings. The question arises, "Whence did the Arabs derive their stronger instinct of causality, as compared with the Greeks and Romans?" Was that intelligent race specially gifted for observation and investigation of facts? Such a supposition conflicts with all we know of Semitic habits of thought, which incline more toward the exercise of dialectical subtilty, fanciful imagining, and speculative meditation.

But for the momentary ascendency of natural science under the influence of Islam, as also for its development in the Christian West so soon as the ban of the scholastic philosophy had been broken, a profounder reason can with some probability be assigned, and one which covers both of these cases. This reason, it is true, is ultimately based on an ethno-psychological peculiarity of the Semitic race. That race, not only directly, through the labors of its Arabic branch, had a part in the creation of modern science, but indirectly, too, the Semites were founders of modern science, owing to the fact that with them originated the monotheistic religions. Modern natural science, paradoxical as the statement is, owes its origin to Christianity.

Between polytheism and monotheism there is this difference, that the former is essentially tolerant, the latter essentially intolerant. Socrates apparently fell the victim of religious zeal, but, as we know, political considerations, and his uncomplying behavior toward his judges, had most influence in procuring his condemnation. At the time of the Acts of the Apostles the Athenians paid worship even to unknown gods, lest any deity should be slighted. The Roman Pantheon admitted all gods, even the gods of conquered nations. The Christians were persecuted by the Roman emperors solely because they were esteemed to be dangerous to the state. On the other hand, Judaism, Christianity, and Islam, have imagined that they each alone possessed the saving faith, and, in a measure, the idea of an absolute truth only came into the world through them. As the Greeks and Romans recognized all sorts of strange gods in addition to their own, and as the Semitic parable of the three rings would have been amiss among them, so, too, with regard to scientific truth, they were not over-particular. Their undeveloped instinct of causality was satisfied when they could assign for a phenomenon some ingenious explanation which pleased the fancy; and their researches of ultimate causes consisted really only of delightful conversations about what appeared admissible. "What is truth?" asked the Roman magistrate, in derision. "I came into the world to bear witness to the truth," said Jesus, and allowed himself to be crucified.

The idea of a God who suffers no other gods beside him, who appears not as a human invention involved in unworthy fables, but as the highest, the absolute Being, who is the centre of all man's moral aspirations, and who with unerring omniscience notes every transgression—this idea of God, entertained for hundreds of years by generation after generation of men, accustomed the mind of man, even in scientific matters, to the thought that throughout the universe the cause of things is one only, and inspired him with the wish to know this cause. Faust's heart-felt cry—

"Du musst, du musst, und kostet' es mein Leben!"[20]

is one quite foreign to the spirit of the ancient world. The fearful earnestness of a religion which claimed for itself all knowledge, which threatened its adversaries with everlasting torture in the next world, and claimed the right even in this life of visiting them with the most horrible punishment, imparted to humanity in the lapse of centuries that character of sobriety and of profundity which certainly fitted them better for patient research than did the light-hearted joy of life favored by the heathen religions. Where so many martyrs were teaching men how they should die for their creed, there must also be those who were ready for science' sake to lead a life of self-denial, or even, if need were, to die for it. In inspiring man with the ardent longing for absolute knowledge, Christianity made atonement for the wrongs its asceticism had for so long done to science.

  1. An address delivered before the Scientific Lectures Association of Cologne. Translated from the German by J. Fitzgerald, A. M., and carefully revised by the author.
  2. "The Old Faith and the New," New York, 1875.
  3. See Du Bois-Reymond's "Untersuchungen über thierische Elektricitat," Berlin, 1848, vol. i., p. xlii.
  4. "History of Civilization," New York, 1878, vol. i., chapter ii.
  5. Fayrer's "Thanatophidia of India," London, 1872, p. 32. Most probably, the number of victims is 20,000. (See also Sir James Paget apud Archibald Dickson, "The Vivisection Question," London, 1877, p. 38.)
  6. See Edmund Burke's lumen dicendi in the proceedings against Warren Hastings apud Macaulay, "Critical and Historical Essays," vol. iv.
  7. "Tent-Life in Siberia," New York, Putnams, 1870, p. 209.
  8. Προμηθεύς δεσμώτης, v., 442, et seq.
  9. See Popular Science Monthly, vol. ix., p. 438.
  10. Περζ τᾣν ὰρεσκοντων τὄις φιλοσὀφοις. Concerning the doubtful authorship of this work, see Monatsberichte der Berliner Akademie, 1874, p. 485.
  11. Whewell, "History of the Inductive Sciences, vol. i., p. 130, London, 1847.
  12. "Which are said to be seven, though they are but six." Ovid gives two mythological hypotheses for the disappearance of the seventh Pleiad, "Fasti," lib. iv., v. 170-178.
  13. Cf. Byron's "Beppo," stanza xiv.
  14. Salvage, "Anatomie du Gladiateur combattant applicable aux Beaux-Arts," 1812, p. iv.
  15. Prescott, "Conquest of Mexico," vol. i., p. 124, et seq.; vol. ii., pp. 60, 108, et seg.
  16. "Die Chemie in ihrer Anwendung auf Agricultur und Phsyiologie," "Einleitung in die Naturgesetze des Feldbaues" p. 86, et seq.
  17. Titi Livii, "Hist. Rom.," lib. xxx., 21, 22. Petrarca falls into the error, not before noted, as far as I am aware, of planting Mount Hæmus (the Balkans) in Thessaly.
  18. "Amores," lib. iii., Eleg. x., v. 35. "If I can, I will hate; if not, I shall love against my will."
  19. This incident occurred in the thirty-second year of the poet's life. The passage from Augustine is as follows in the original: "Et eunt homines admirari alta montium, et ingentes fluctus maris, et latissimos lapsus fluminum, et oceani ambitum, et gyros siderum, et relinquunt seipsos."
  20. "Thou must, thou must, though it cost me my life!"