At Alexandria the most notable Greek scientific work had been done. Euclid (323-283 B.C.) in geometry; Aristarchus (third century B.C.), who explained the motion of the earth; Eratosthenes (270-196 B.C.), who measured the size of the earth; Archimedes (270?-212 B.C.), a pupil of Euclid's, who applied science in many ways and laid the foundations of dynamics; Hipparchus (160-125 B.C.), the father of astronomy, who studied the heavens and catalogued the stars, were among the more famous Greeks who studied and taught there in the days when Alexandria had succeeded Athens as the intellectual capital of the Greek world. Some remarkable advances also were made in the study of human anatomy and medicine by two Greeks, Herophilus (335-280 B.C.) and Erasistratus (d. 280 B.C.), who apparently did much dissecting.

But even at Alexandria the promise of Greek science was unfulfilled.

Despite many notable speculations and scientific advances, the hopeful beginnings did not come to any large fruitage, and the great contribution made by the Greeks to world civilization was less along scientific lines than along the lines of literature and philosophy. Their great strength lay in the direction of philosophic speculation, and this tendency to speculate, rather than to observe and test and measure and record, was the fundamental weakness of all Greek science. The Greeks never advanced in scientific work to the invention and perfection of instruments for the standardization of their observations. As a result they pa.s.sed on to the mediaeval world an extensive "book science" and not a little keen observation, of which the works of Aristotle and the Alexandrian mathematicians and astronomers form the most conspicuous examples, but little scientific knowledge of which the modern world has been able to make much use. The "book science" of the Greeks, and especially that of Aristotle, was highly prized for centuries, but in time, due to the many inaccuracies, had to be discarded and done anew by modern scholars.

The Romans, as we have seen (chapter III), were essentially a practical people, good at getting the work of the world done, but not much given to theoretical discussion or scientific speculation. They were organizers, governors, engineers, executives, and literary workers rather than scientists. They executed many important undertakings of a practical character, such as the building of roads, bridges, aqueducts, and public buildings; organized government and commerce on a large scale; and have left us a literature and a legal system of importance, but they contributed little to the realm of pure science. The three great names in science in all their history are Strabo the geographer (63 B.C.-24 A.D.); Pliny the Elder (23-79 A.D.), who did notable work as an observer in natural history; and Galen (a Roman-Greek), in medicine. They, like the Greeks, were pervaded by the same fear that their science might prove useful, whereas they cultivated it largely as a mental exercise (R. 203).

THE CHRISTIAN REACTION AGAINST INQUIRY. The Christian att.i.tude toward inquiry was from the first inhospitable, and in time became exceedingly intolerant. The tendency of the Western Church, it will be remembered (p.

94), was from the first to reject all h.e.l.lenic learning, and to depend upon emotional faith and the enforcement of a moral life. By the close of the third century the hostility to pagan schools and h.e.l.lenic learning had become so p.r.o.nounced that the _Apostolic Const.i.tutions_ (R. 41) ordered Christians to abstain from all heathen books, which could contain nothing of value and only served "to subvert the faith of the unstable." In 401 A.D. the Council of Carthage forbade the clergy to read any heathen author, and Greek learning now rapidly died out in the West. For a time it was almost entirely lost. In consequence Greek science, then best represented by Alexandrian learning, and which contained much that was of great importance, was rejected along with other pagan learning. The, very meager scientific knowledge that persisted into the Middle Ages in the great mediaeval textbooks (p. 162), as we have seen in the study of the Seven Liberal Arts (chapter VII), came to be regarded as useful only in explaining pa.s.sages of Scripture or in ill.u.s.trating the ways of G.o.d toward man. The one and only science worthy of study was Theology, to which all other learning tended (see Figure 44, p. 154).

The history of Christianity throughout all the Dark Ages is a history of the distrust of inquiry and reason, and the emphasis of blind emotional faith. Mysticism, good and evil spirits, and the interpretation of natural phenomena as manifestations of the Divine will from the first received large emphasis. The worship of saints and relics, and the great development of the sensuous and symbolic, changed the earlier religion into a crude polytheism. During the long period of the Middle Ages the miraculous flourished. The most extreme superst.i.tion pervaded all ranks of society. Magic and prayers were employed to heal the sick, restore the crippled, foretell the future, and punish the wicked. Sacred pools, the royal touch, wonder-working images, and miracles through prayer stood in the way of the development of medicine (R. 204). Disease was attributed to satanic influence, and a regular schedule of prayers for cures was in use.

Sanitation was unknown. Plagues and pestilences were manifestations of Divine wrath, and hysteria and insanity were possession by the devil to be cast out by whipping and torture. One's future was determined by the position of the heavenly bodies at the time of birth. Eclipses, meteors, and comets were fearful portents of Divine displeasure:

Eight things there be a Comet brings, When it on high doth horrid rage; Wind, Famine, Plague, and Death to Kings, War, Earthquakes, Floods, and Direful Change. [4]

The literature on magic was extensive. The most miraculous happenings were recorded and believed. Trial by ordeal, following careful religious formulae, was common before 1200, though prohibited shortly afterward by papal decrees (1215, 1222). The insistence of the Church on "the willful, devilish character of heresy," and the extension of heresy to cover almost any form of honest doubt or independent inquiry, caused an intellectual stagnation along lines of scientific investigation which was not relieved for more than a thousand years. The many notable advances in physics, chemistry, astronomy, and medicine made by Moslem scholars (chapter VIII) were lost on Christian Europe, and had to be worked out again centuries later by the scholars of the western world. Out of the astronomy of the Arabs the Christians got only astrology; out of their chemistry they got only alchemy. Both in time stood seriously in the way of real scientific thinking and discovery.

GROWING TOLERANCE CHANGED BY THE PROTESTANT REVOLTS. After the rise of the universities, the expansion of the minds of men which followed the Crusades and the revival of trade and industry, the awakening which came with the revival of the old learning and the rise of geographical discovery, the church authorities a.s.sumed a broader and a more tolerant att.i.tude toward inquiry and reason than had been the case for hundreds of years. It would have been surprising, with the large number of university- trained men entering the service of the Church, had this not been the case. By the middle of the fifteenth century it looked as though the Renaissance spirit might extend into many new directions, and by 1500 the world seemed on the eve of important progress in almost every line of endeavor. As was pointed out earlier (p. 259), the Church was more tolerant than it had been for centuries, and about the year 1500 was the most stimulating time in the history of our civilization since the days of Alexandria and ancient Rome.

In 1517 Luther nailed his theses to the church door in Wittenberg. The Church took alarm and attempted to crush him, and soon the greatest contest since the conflict between paganism and Christianity was on.

Within half a century all northern lands had been lost to the ancient Church (see map, p. 296); the first successful challenge of its authority during its long history.

The effect of these religious revolts on the att.i.tude of the Church toward intellectual liberty was natural and marked. The tolerance of inquiry recently extended was withdrawn, and an era of steadily increasing intolerance set in which was not broken for more than a century. In an effort to stop the further spread of the heresy, the Church Council of Trent (1545-63) adopted stringent regulations against heretical teachings (p. 303), while the sword and torch and imprisonment were resorted to to stamp out opposition and win back the revolting lands. A century of merciless warfare ensued, and the hatreds engendered by the long and bitter struggle over religious differences put both Catholic and Protestant Europe in no tolerant frame of mind toward inquiry or new ideas. The Inquisition, a sort of universal mediaeval grand jury for the detection and punishment of heretics, was revived, and the Jesuits, founded in 1534-40, were vigorous in defense of the Church and bitter in their opposition to all forms of independent inquiry and Protestant heresy.

It was into this post-Reformation atmosphere of suspicion and distrust and hatred that the new critical, inquiring, questioning spirit of science, as applied to the forces of the universe, was born. A century earlier the first scientists might have obtained a respectful hearing, and might have been permitted to press their claims; after the Protestant Revolts had torn Christian Europe asunder this could hardly be. As a result the early scientists found themselves in no enviable position. Their theories were bitterly a.s.sailed as savoring of heresy; their methods and purposes were alike suspected; and any challenge of an old long-accepted idea was likely to bring a punishment that was swift and sure. From the middle of the sixteenth to the middle of the seventeenth century was not a time when new ideas were at a premium anywhere in western Europe. It was essentially a period of reaction, and periods of reaction are not favorable to intellectual progress. It was into this century of reaction that modern scientific inquiry and reasoning, itself another form of expression of the intellectual att.i.tudes awakened by the work of the humanistic scholars of the Italian Renaissance, made its first claim for a hearing.

THE BEGINNINGS OF MODERN SCIENTIFIC METHOD. One of the great problems which has always deeply interested thinking men in all lands is the nature and const.i.tution of the material universe, and to this problem people in all stages of civilization have worked out for themselves some kind of an answer. It was one of the great speculations of the Greeks, and it was at Alexandria, in the period of its decadence, that the Egyptian geographer Ptolemy (138 A.D.) had offered an explanation which was accepted by Christian Europe and which dominated all thinking on the subject during the Middle Ages. He had concluded that the earth was located at the center of the visible universe, immovable, and that the heavenly bodies moved around the earth, in circular motion, fixed in crystalline spheres. [5]

This explanation accorded perfectly with Christian ideas as to creation, as well as with Christian conceptions as to the position and place of man and his relation to the heavens above and to a h.e.l.l beneath. This theory was obviously simple and satisfactory, and became sanctified with time. As we see it now the wonder is that such an explanation could have been accepted for so long. Only among an uninquisitive people could so imperfect a theory have endured for over fourteen centuries.

[Ill.u.s.tration: FIG. 113. NICHOLAS KOPERNIK (Copernicus), (1473-1543)]

In 1543 a Bohemian church canon and physician by the name of Nicholas Copernicus published his _De Revolutionibus...o...b..um Celestium_, in which he set forth the explanation of the universe which we now know. He piously dedicated the work to Pope Paul III, and wisely refrained from publishing it until the year of his death. [6] Anything so completely upsetting the Christian conception as to the place and position of man in the universe could hardly be expected to be accepted, particularly at the time of its publication, without long and bitter opposition.

In the dedicatory letter (R. 205), Copernicus explains how, after feeling that the Ptolemaic explanation was wrong, he came to arrive at the conclusions he did. The steps he set forth form an excellent example of a method of thinking now common, but then almost unknown. They were:

1. Dissatisfaction with the old Ptolemaic explanation.

2. A study of all known literature, to see if any better explanation had been offered.

3. Careful thought on the subject, until his thinking took form in a definite theory.

4. Long observation and testing out, to see if the observed facts would support his theory.

5. The theory held to be correct, because it reduced all known facts to a systematic order and harmony.

This is as clear a case of inductive reasoning as was L. Valla's exposure of the forgery of the so-called "Donation of Constantine," an example of deductive reasoning. Both used a new method--the method of modern scholarship. In both cases the results were revolutionary. As Petrarch stands forth in history as the first modern cla.s.sical scholar, so Copernicus stands forth as the first modern scientific thinker. The beginnings of all modern scientific investigation date from 1543. Of his work a recent writer (E. C. J. Morton) has said:

Copernicus cannot be said to have flooded with light the dark places of nature--in the way that one stupendous mind subsequently did-- but still, as we look back through the long vista of the history of science, the dim t.i.tanic figure of the old monk seems to rear itself out of the dull flats around it, pierces with its head the mists that overshadow them, and catches the first gleam of the rising sun,...

Like some iron peak, by the Creator Fired with the red glow of the rushing morn.

[Ill.u.s.tration: FIG. 114. TYCHO BRAHE (1546-1601)]

THE NEW METHOD OF INQUIRY APPLIED BY OTHERS. At first Copernicus' work attracted but little attention. An Italian Dominican by the name of Giordano Bruno (1548-1600), deeply impressed by the new theory, set forth in Latin and Italian the far-reaching and majestic implications of such a theory of creation, and was burned at the stake at Rome for his pains. A Dane, Tycho Brahe, after twenty-one years of careful observation of the heavens, during which time he collected "a magnificent series of observations, far transcending in accuracy [7] and extent anything that had been accomplished by his predecessors," showed Aristotle to be wrong in many particulars. His observations of the comet of 1577 led him to conclude that the theory of crystalline spheres was impossible, and that the common view of the time as to their nature [8] was absurd. In 1609 a German by the name of Johann Kepler (1571-1630), using the records of observations which Tycho Brahe had acc.u.mulated and applying them to the planet Mars, proved the truth of the Copernican theory and framed his famous three laws for planetary motion.

[Ill.u.s.tration: FIG. 115. GALILEO GALILEI (1564-1642)]

Finally an Italian, Galileo Galilei, a professor at the University of Pisa, developing a telescope that would magnify to eight diameters, discovered Jupiter's satellites and Saturn's rings. The story of his discovery of the satellites of Jupiter is another interesting ill.u.s.tration of the careful scientific reasoning of these early workers (R. 206).

Galileo also made a number of discoveries in physics, through the use of new scientific methods, which completely upset the teachings of the Aristotelians, and made the most notable advances in mechanics since the days of Archimedes. For his p.r.o.nounced advocacy of the Copernican theory he was called to Rome (1615) by the Cardinals of the Inquisition, the Copernican theory was condemned as "absurd in philosophy" and as "expressly contrary to Holy Scripture," and Galileo was compelled to recant (1616) his error. [9] For daring later (1632) to a.s.sume that he might, under a new Pope, defend the Copernican theory, even in an indirect manner, he was again called before the inquisitorial body, compelled to recant and abjure his errors (R. 207) to escape the stake, and was then virtually made a prisoner of the Inquisition for the remainder of his life. So strongly had the forces of medievalism rea.s.serted themselves after the Protestant Revolts!

[Ill.u.s.tration: FIG. 116. SIR ISAAC NEWTON (1642-1727)]

Finally the English scholar Newton (1642-1728), in his _Principia_ (1687), settled permanently all discussions as to the Copernican theory by his wonderful mathematical studies. He demonstrated mathematically the motions of the planets and comets, proved Kepler's laws to be true, explained gravitation and the tides, made clear the nature of light, and reduced dynamics to a science. Of his work a recent writer, Karl Pearson, has said:

The Newtonian laws of motion form the starting point of most modern treatises on dynamics, and it seems to me that physical science, thus started, resembles the mighty genius of an Arabian tale emerging amid metaphysical exhalations from the bottle in which for long centuries it had been corked down.

So far-reaching in its importance was the scientific work of Newton that Pope's couplet seems exceedingly applicable:

Nature and Nature's laws lay hid in night; G.o.d said, "Let Newton be," and all was light.

THE NEW METHOD APPLIED IN OTHER FIELDS. The new method of study was soon applied to other fields by scholars of the new type, here and there, and always with fruitful results. The Englishman, William Gilbert (1540-1603) published, in 1600, his _De Arte Magnetica_, and laid the foundations of the modern study of electricity and magnetism. A German-Swiss by the name of Hohenheim, but who Latinized his name to Paracelsus (1493-1541), and who became a professor in the medical faculty at the University of Basle, in 1526 broke with mediaeval traditions by being one of the first university scholars to refuse to lecture in Latin. He ridiculed the medical theories of Hippocrates (p. 197) and Galen (p. 198), and, regarding the human body as a chemical compound, began to treat diseases by the administration of chemicals. A Saxon by the name of Landmann, who also Latinized his name to Agricola (1494-1555), applied chemistry to mining and metallurgy, and a French potter named Bernard Palissy (c. 1500- 88) applied chemistry to pottery and the arts. To Paracelsus, Agricola, and Palissy we are indebted for having laid, in the sixteenth century, the foundations of the study of modern chemistry.

[Ill.u.s.tration: FIG. 117. WILLIAM HARVEY (1578-1657)]

A Belgian by the name of Vesalius (1514-64) was the first modern to dissect the human body, and for so doing was sentenced by the Inquisition to perform a penitential journey to Jerusalem. One of his disciples discovered the valves in the veins and was the teacher of the Englishman, William Harvey, who discovered the circulation of the blood and later (1628) dared to publish the fact to the world. These men established the modern studies of anatomy and physiology. Another early worker was a Swiss by the name of Conrad Gessner (1516-65), who observed and wrote extensively on plants and animals, and who stands as the first naturalist of modern times.

The sixteenth century thus marks the rise of modern scientific inquiry, and the beginnings of the study of modern science. The number of scholars engaged in the study was still painfully small, and the religious prejudice against which they worked was strong and powerful, but in the work of these few men we have not only the beginnings of the study of modern astronomy, physics, chemistry, metallurgy, medicine, anatomy, physiology, and natural history, but also the beginnings of a group of men, destined in time to increase greatly in number, who could see straight, and who sought facts regardless of where they might lead and what preconceived ideas they might upset. How deeply the future of civilization is indebted to such men, men who braved social ostracism and often the wrath of the Church as well, for the, to them, precious privilege of seeing things as they are, we are not likely to over- estimate. In time their work was destined to reach the schools, and to materially modify the character of all education.

[Ill.u.s.tration: FIG. 118. FRANCIS BACON (1561-1626)]

HUMAN REASON IN THE INVESTIGATION OF NATURE. To the English statesman and philosopher, Francis Bacon, more than to any one else, are we indebted for the proper formulation and statement of this new scientific method. Though not a scientist himself, he has often been termed "the father of modern science." Seeing clearly the importance of the new knowledge, he broke entirely with the old scholastic deductive logic as expressed in the _Organon_, of Aristotle, and formulated and expressed the methods of inductive reasoning in his _Novum Organum_, published in 1620. In this he showed the insufficiency of the method of argumentation; a.n.a.lyzed and formulated the inductive method of reasoning, of which his study as to the nature of heat [10] is a good example; and pointed out that knowledge is a process, and not an end in itself; and indicated the immense and fruitful field of science to which the method might be applied. By showing how to learn from nature herself he turned the Renaissance energy into a new direction, and made a revolutionary break with the disputations and deductive logic of the Aristotelian scholastics which had for so long dominated university instruction.

In formulating the new method he first pointed out the defects of the learning of his time, which he cla.s.sified under the head of "distempers,"

three in number, and as follows:

1. _Fantastic learning_: Alchemy, magic, miracles, old-wives, tales, credulities, superst.i.tions, pseudo-science, and impostures of all sorts inherited from an ignorant past, and now conserved as treasures of knowledge.

2. _Contentious learning_: The endless disputations of the Scholastics about questions which had lost their significance, deductive in character, not based on any observation, not aimed primarily to arrive at truth, "fruitful of controversy, and barren of effect."

3. _Delicate learning_: The new learning of the humanistic Renaissance, verbal and not real, stylish and polished but not socially important, and leading to nothing except a mastery of itself.

As an escape from these three types of distempers, which well characterized the three great stages in human progress from the sixth to the fifteenth centuries, Bacon offered the inductive method, by means of which men would be able to distinguish true from false, learn to see straight, create useful knowledge, and fill in the great gaps in the learning of the time by actually working out new knowledge from the unknown. The collecting, organizing, comparing, questioning, and inferring spirit of the humanistic revival he now turned in a new direction by organizing and formulating for the work a new _Organum_ to take the place of the old _Organon_ of Aristotle. In Book 1 he sets forth some of the difficulties (R. 208) with which those who try new experiments or work out new methods of study have to contend from partisans of old ideas.

The _Novum Organum_ showed the means of escape from the errors of two thousand years by means of a new method of thinking and work. Bacon did not invent the new method--it had been used since man first began to reason about phenomena, and was the method by means of which Wycliffe, Luther, Magellan, Copernicus, Brahe, and Gilbert had worked--but he was the first to formulate it clearly and to point out the vast field of new and useful knowledge that might be opened up by applying human reason, along inductive lines, to the investigation of the phenomena of nature.

His true service to science lay in the completeness of his a.n.a.lysis of the inductive process, and his declaration that those who wish to arrive at useful discoveries must travel by that road. As Macaulay well says, in his essay on Bacon:

He was not the maker of that road; he was not the discoverer of that road; he was not the person who first surveyed and mapped that road.

But he was the person who first called the public attention to an inexhaustible mine of wealth which had been utterly neglected, and which was accessible by that road alone.

To stimulate men to the discovery of useful truth, to turn the energies of mankind--even slowly--from a.s.sumption and disputation to patient experimentation, [11.] and to give an impress to human thinking which it has retained for centuries, is, as Macaulay well says, "the rare prerogative of a few imperial spirits." Macaulay's excellent summary of the importance of Bacon's work (R. 209) is well worth reading at this point.