Astronomy was looked upon as an exceedingly practical study, because it was by this science that the festivals of the Church were dated. The astronomers of the time knew something of eclipses and they had tables of stars and planets. They studied the observations made by the wise men of the East for many centuries, and really learned a great deal. Unfortunately, they made one great mistake. For four hundred years it has been known that the earth and the other planets revolve around the sun. In the Middle Ages, however, people believed that the sun revolved about the earth. The sky, they thought, was a vast hollow sphere which revolved once a day. It was because of this mistake that when they tried to reason about what they had seen, their conclusions were all wrong, no matter how correct their observations might have been.

Now when people believed that the whole starry universe was made for their especial benefit, it was not very unreasonable to take it for granted that the stars, their arrangement in the sky, and their movements had something to do with human affairs. Anything unusual was always alarming. Comets were a source of terror. No one knew whence they came or whither they were going. They were uncanny, and even the educated feared some awful disaster when one of these fiery wanderers appeared in the sky. In the middle of the fifteenth century, a large comet was seen which terrified all Europe. Even before its appearance people were in dread, for the Turks had crossed the Hellespont, and there was reason to believe that they would overrun the Continent. Then came the added horror of the comet, and no one could tell what awful calamity this might portend. It is no wonder that the Pope ordered the church bells to be rung at noon, and the Ave Maria to be said three times a day instead of twice. To this prayer was added the petition, "Lord, save us from the Devil, the Turk, and the Comet."

Comets, fortunately, did not appear very often, but it was believed that the other heavenly bodies, also, had an effect upon people and could make them successful or unsuccessful. A man who could interpret the significance of the heavens was called an astrologer, and the science, or make-believe science, was called astrology. When a child was born, the father hurried away to an astrologer, if he could afford to consult one, to have what was called a horoscope calculated, that is, to have its future life predicted according to the aspect of the heavens at its birth. The most important constellations are situated in a wide belt around the heavens called the zodiac, and are therefore called the signs of the zodiac. There are twelve of these constellations: Aries, or the ram; Gemini, or the twins; Leo, the lion; Capricornus, or the goat; and others. The one which was in the ascendant, or just risen above the eastern horizon, at the time of the child's birth, was supposed to have great influence upon his life. But this was only the beginning of the astrologer's calculations. He fixed a point in the sky according to the position of the sun and moon at the time, and, beginning at that, he divided the heavens into twelve "houses." These houses were divided and subdivided. To each house some planet was assigned, and every planet had its special influence. Jupiter, for instance, had power to give one riches and honors, Venus would bestow love and warm friendship. If, then, Jupiter chanced to be in the house assigned to him and in a favorable sign, his influence upon the child would be so strong that he could hardly help winning wealth and distinction. People consulted astrologers about the proper time to begin a journey or a business undertaking, about a favorable day for a marriage or the coronation of a king, and, indeed, so far as they could afford it, about an endless number of even the smallest affairs of life.

Even in medicine the position of the planets was of the utmost importance. When a doctor was sent for, he came on horseback with the bells on his bridle rein jingling so merrily that he could be heard a long way off. An assistant followed him and as many servants as his purse would permit, bearing five or six instruments and numerous sorts of ointment. When he reached the home of the sick man, his first business was not to count his pulse or note his temperature, but to inquire under what constellation he was born. With this knowledge he would set to work to ascertain what remedy would be of service. But, however valuable the medicine might be and however much it might be needed, it must not be taken when the moon was in an unfavorable sign; for then it would do harm rather than good. When an epidemic appeared, it was of course laid to the stars, or the power of evil spirits. Two unfavorable planets meeting in the same degree of the zodiac would account for any pestilence, or so people thought. There was, however, one other way of explaining the appearance of any general illness, and that was to lay it to the Jews. In France, Germany, and Italy, Jews were many times accused of poisoning the wells or even the air, and were either imprisoned or put to death on this charge.

Some of the medicines of the time were most absurd, and many were revolting. Gold filings were thought good for leprosy, and so was an adder boiled with leeks. A more agreeable remedy for the illness of a child was to weigh the child and then offer up at some shrine its weight in bread or grain or cheese or wax. Many herbs were used, such as sage, wormwood, and pennyroyal. Medicines were hardly expected to do much good of themselves. To make a dose powerful, the sick man must repeat a certain Psalm twelve times together with several Paternosters while the medicine was being prepared. It was far more likely to effect a cure if he could take it at the shrine of some saint. With some remedies one should always repeat a charm.

Physicians are described as wearing expensive robes of silk with trimmings of fur. "Physic" in Piers Plowman  wears a hood richly trimmed with fur, and gold buttons on his cloak. They demanded large fees and received them. In other cases a man might choose whether to purchase or to do without; but in illness there was left him only the highwayman's choice, "Your money or your life." Chaucer makes a fling at these exorbitant charges and says of the learned doctor among his Canterbury pilgrims,

Poor folk had not the money necessary to buy their lives of these great doctors, and therefore they went with their ailments to the barber. He was permitted by law to apply plasters and ointments to wounds that did not threaten to become dangerous, and often to give simple remedies. In most diseases, the first treatment was to bleed the patient, and the barber's pole of to-day is a reminder of the custom. In France, before any serious operation could be performed, the bishop or the feudal lord of the patient had to be consulted. were made use of for remedies or to keep away illness. These consisted of a stone or a piece of metal upon which was cut a figure or an inscription. In the earlier part of the Middle Ages, runes were often used for the inscriptions. These were only the letters of the earliest northern alphabet; but so few people could read that they were looked upon as something having magical powers. In later times, most talismans were brought from the East, and were engraved with inscriptions in Persian or Arabic. Even in health these tokens were highly valued. A species of charm known as a philter was supposed to have the power to arouse love. Sometimes a magic drink for the same purpose was prepared and given to the person in question; but oftener the one who wished to become beloved wore a philter consisting of powdered loadstone, nail-parings, and human blood, or other absurd combinations. If a man wished to win honor, he might cut the image of Jupiter on a white stone or a piece of tin; and if this was done when the planets were favorable, he would be sure to gain his wish. Of course there were stories upon stories of cures wrought in illness by such means. Roger Bacon, who was perhaps the most sensible scientific man of his age, declared that charms and talismans were of much value; but he explained that this was not because they acted as remedies, but because they made the patient calm and hopeful and thus aided in his recovery.

It is a wonder, however, that when people were sick, they should ever have expected charms or anything else to be of service, for so many illnesses were thought to be caused by witchcraft. Some persons were believed to possess what was known as the "evil eye." Whoever first met their gaze in the morning was sure to pine away and die; and, indeed, some evil was likely to befall one upon whom they looked at any hour of the day. If a man wished to take the life of an enemy, he could do so conveniently by driving a nail or a wooden peg into a wall, pronouncing the name of the victim at each blow. Another way was to shoot an arrow into the air, praying to some demon to direct its flight to the person named. This arrow would leave a wound which was invisible, to be sure, but which would certainly cause death within three days. Another method of ridding one's self of a foe was to make an image of him in wax. Under the right arm of the image one must place the heart of a swallow, and under the left arm its liver. Whatever injury was done to the figure was supposed to be felt by the person whom it represented. If a needle was pushed into its side, the person was expected to feel a sharp pain in the side. In case of sudden death, people thought first of witchcraft, and it was sometimes dangerous to the safety of even an innocent man if his enemy died too unexpectedly. It was far safer to build fire of wood and vervain, set the waxen image before it, and let it melt. Then the person would slowly but surely waste away. This belief in the waxen image was so firmly fixed that if a man had a hawk which he could not succeed in managing, he would sometimes send a waxen image of it to the shrine of some saint that he might have better success.

Besides the danger of being bewitched, there were the four "humors," or qualities, to be reckoned with. All things are made of earth, air, fire, and water, but in varying proportions, declared the wisdom of the Middle Ages. Earth has the humor of being cold and dry; water of being cold and moist; air of being hot and moist; and fire of being hot and dry. It went on further to say that earth corresponded to autumn and the melancholic temperament; water to winter and the phlegmatic; air to spring and the sanguine; and fire to summer and the choleric. If these humors were perfectly balanced, the person was well—and to this day we keep the phrase "good-humored"—but if there chanced to be too much of any one of them, illness was the result; and it was the business of the doctor to decide which humor was in excess.

Mixtures to cure diseases were often prepared by the alchemists, or chemists of the time. With the chanting of charms and the drawing of magic circles an alchemist would prepare a draught warranted to heal a sick man, give pleasant dreams, or make one invulnerable. To the common folk, their work was so mysterious and the sights and sounds from their laboratories so strange and awe-inspiring that whenever they passed the house of an alchemist, they crossed themselves and prayed to be delivered from the power of the Devil. They were ready to believe the most absurd stories of the abilities of these men. One was said to be able to call back to his purse whatever coins he might have paid out of it. Another was believed to have made a wooden image that would rise from its seat and open the door whenever a knock was heard. Most mysterious and most popular of all such wonders was the brazen head which Roger Bacon was said to have made. Success in his undertakings and a vast amount of knowledge were to come to him if he only heard it speak. When he had become too weary to listen any longer, he set an assistant to watch it. While the master slept, the head suddenly spoke. "Time is," it said. "There is no use in arousing my master to hear what every one knows," thought the assistant; and he let Bacon sleep on. The head spoke again, and said, "Time was." This, too, the assistant thought was of no importance. Half an hour later it spoke for the third time. It said, "Time is past," fell from its place, and was broken to fragments; and so it was that Bacon himself, its maker, never heard it speak.