The 100 Most Influential Scientists of All Time (7 page)

Any of these considerations alone could account for Copernicus's delay in publishing his work. (He remarked in the preface to
De revolutionibus
that he had chosen to withhold publication not for merely the nine years recommended by the Roman poet Horace but for 36 years, four times that period.) When a description of the main elements of the heliocentric hypothesis was first published in 1540 and 1541 in the
Narratio Prima
(“First Narration”), it was not under Copernicus's own name but under that of the 25-year-old Georg Rheticus, a Lutheran from the University of Wittenberg, Germany, who stayed with Copernicus at Frauenburg for about two and a half years, between 1539 and 1542. The
Narratio prima
was, in effect, a joint production of Copernicus and Rheticus, something of a “trial balloon” for the main work. It provided a summary of the theoretical principles contained in the manuscript of
De revolutionibus
, emphasized their value for computing new planetary tables, and presented Copernicus as following admiringly in the footsteps of Ptolemy even as he broke fundamentally with his ancient predecessor. It also provided what was missing from the
Commentariolus
: a basis for accepting the claims of the new theory.

Both Rheticus and Copernicus knew that they could not definitively rule out all possible alternatives to the heliocentric theory. But they could underline what Copernicus's theory provided that others could not: a singular method for ordering the planets and for calculating the relative distances of the planets from the Sun. Rheticus compared this new universe to a well-tuned musical instrument and to the interlocking wheel-mechanisms of a clock. In the preface to
De revolutionibus
, Copernicus used an image from Horace's
Ars poetica
(“Art of Poetry”). The theories of his predecessors, he wrote, were like a human figure in which the arms, legs, and head were put together in the form of a disorderly monster. His own representation of the universe, in contrast, was an orderly whole in which a displacement of any part would result in a disruption of the whole. In effect, a new criterion of scientific adequacy was advanced together with the new theory of the universe.

(b. Nov. 11 or Dec. 17, 1493, Einsiedeln, Switz.—d. Sept. 24, 1541, Salzburg, Archbishopric of Salzburg [now in Austria])

P
hilippus Aureolus Theophrastus Bombastus Von Hohenheim, better known as Paracelsus, was a German-Swiss physician and alchemist. He established the role of chemistry in medicine. He published
Der grossen Wundartzney
(“Great Surgery Book”) in 1536 and a clinical description of syphilis in 1530.

Paracelsus is said to have graduated from the University of Vienna with a baccalaureate in medicine in 1510. It is believed that he received his doctoral degree in 1516 from the University of Ferrara in Italy, where he was free to express his rejection of the prevailing view that the stars and planets controlled all the parts of the human body. He is thought to have begun using the name “para-Celsus” (above or beyond Celsus) at about that time because he regarded himself as even greater than Celsus, a renowned 1st-century Roman physician.

Soon after taking his degree, he set out upon many years of wandering through Europe and took part in the “Netherlandish wars” as an army surgeon. Later Paracelsus went to Russia, was held captive by the Tatars, escaped into Lithuania, went south into Hungary, and again served as an army surgeon in Italy in 1521. Ultimately his wanderings brought him to Egypt, Arabia, the Holy Land, and, finally, Constantinople. Everywhere he sought out the most learned exponents of practical alchemy, not only to discover the most effective means of medical treatment but also—and even more important—to discover “the latent forces of Nature,” and how to use them.

In 1524 Paracelsus returned to his home at Villach in southern Austria to find that his fame for many miraculous cures had preceded him. He was subsequently appointed town physician and lecturer in medicine at the University of Basel in Switzerland, and students from all parts of Europe came to the city to hear his lectures. Pinning a program of his forthcoming lectures to the notice board of the university on June 5, 1527, he invited not only students but anyone and everyone.

Three weeks later, on June 24, 1527, Paracelsus reportedly burned the books of Avicenna, the Arab “Prince of Physicians,” and those of Galen, in front of the university.
This incident is said to have recalled in many people's minds Martin Luther, who on Dec. 10, 1520, at the Elster Gate of Wittenberg had burned a papal bull, or edict, that threatened excommunication. While Paracelsus seemingly remained a Catholic to his death, it is suspected that his books were placed on the
Index Expurgatorius
, a catalogue of books from which passages of text considered immoral or against the Catholic religion are removed.

Paracelsus reached the peak of his career at Basel. In his lectures he stressed the healing power of nature and discouraged the use of methods of treating wounds, such as padding with moss or dried dung, that prevented natural draining. He also attacked many other medical malpractices of his time, including the use of worthless salves, fumigants, and drenches. However, by the spring of 1528 Paracelsus fell into disrepute with local doctors, apothecaries, and magistrates. He left Basel, heading first to Colmar in Upper Alsace, about 50 miles north of the university. He continued to travel for the next eight years. During this time, he revised old manuscripts and wrote new treatises. With the publication of
Der grossen Wundartzney
in 1536 he restored, and even extended, the revered reputation he had earned at Basel.

In 1530 Paracelsus wrote a clinical description of syphilis, in which he maintained that the disease could be successfully treated by carefully measured doses of mercury compounds taken internally. He stated that the “miners' disease” (silicosis) resulted from inhaling metal vapours and was not a punishment for sin administered by mountain spirits. He was the first to declare that, if given in small doses, “what makes a man ill also cures him,” an anticipation of the modern practice of homeopathy. Paracelsus is said to have cured many people in the plague-stricken
town of Stertzing in the summer of 1534 by administering orally a pill made of bread containing a minute amount of the patient's excreta he had removed on a needle point.

Paracelsus was the first to connect goitre with minerals, especially lead, in drinking water. He prepared and used new chemical remedies, including those containing mercury, sulfur, iron, and copper sulfate—thus uniting medicine with chemistry, as the first
London Pharmacopoeia
, in 1618, indicates. Paracelsus, in fact, contributed substantially to the rise of modern medicine, including psychiatric treatment.

(b. Dec. 1514, Brussels [now in Belgium]—d. June 1564, island of Zacynthus, Republic of Venice [now in Greece])

A
ndreas Vesalius (Flemish: Andries Van Wesel) was a Renaissance Flemish physician who revolutionized the study of biology and the practice of medicine by his careful description of the anatomy of the human body. Basing his observations on dissections he made himself, he wrote and illustrated the first comprehensive textbook of anatomy.

Vesalius was from a family of physicians and pharmacists. He attended the Catholic University of Leuven (Louvain) from 1529 to 1533. From 1533 to 1536, he studied at the medical school of the University of Paris, where he learned to dissect animals. He also had the opportunity to dissect human cadavers, and he devoted much of his time to a study of human bones, at that time easily available in the Paris cemeteries.

In 1536 Vesalius returned to his native Brabant to spend another year at the Catholic University of Leuven, where the influence of Arab medicine was still dominant.
Following the prevailing custom, he prepared, in 1537, a paraphrase of the work of the 10th-century Arab physician, Rhazes, probably in fulfillment of the requirements for the bachelor of medicine degree. He then went to the University of Padua, a progressive university with a strong tradition of anatomical dissection. On receiving the M.D. degree the same year, he was appointed a lecturer in surgery with the responsibility of giving anatomical demonstrations. Since he knew that a thorough knowledge of human anatomy was essential to surgery, he devoted much of his time to dissections of cadavers and insisted on doing them himself, instead of relying on untrained assistants.

At first, Vesalius had no reason to question the theories of Galen, the Greek physician who had served the emperor Marcus Aurelius in Rome and whose books on anatomy were still considered as authoritative in medical education in Vesalius's time. In January 1540, breaking with this tradition of relying on Galen, Vesalius openly demonstrated his own method—doing dissections himself, learning anatomy from cadavers, and critically evaluating ancient texts. He did so while visiting the University of Bologna. Such methods soon convinced him that Galenic anatomy had not been based on the dissection of the human body, which had been strictly forbidden by the Roman religion. Galenic anatomy, he maintained, was an application to the human form of conclusions drawn from the dissections of animals, mostly dogs, monkeys, or pigs.

It was this conclusion that he had the audacity to declare in his teaching as he hurriedly prepared his complete textbook of human anatomy for publication. Early in 1542 he traveled to Venice to supervise the preparation of drawings to illustrate his text, probably in the studio of the great Renaissance artist Titian. The drawings of his dissections were engraved on wood blocks,
which he took, together with his manuscript, to Basel, Switzerland, where his major work,
De humani corporis fabrica libri septem
(“The Seven Books on the Structure of the Human Body”), commonly known as the
Fabrica
, was printed in 1543. In this epochal work, Vesalius deployed all his scientific, humanistic, and aesthetic gifts. The
Fabrica
was a more extensive and accurate description of the human body than any put forward by his predecessors. It gave anatomy a new language, and, in the elegance of its printing and organization, an unparalleled perfection.

Early in 1543, Vesalius left for Mainz, to present his book to the Holy Roman emperor Charles V, who engaged him as regular physician to the household. Thus, when not yet 28 years old, Vesalius had attained his goal. After relinquishing his post in Padua, and returning in the spring of 1544 to his native land to marry Anne van Hamme, he took up new duties in the service of the Emperor on his travels in Europe. From 1553 to 1556 Vesalius spent most of his time in Brussels, where he built an imposing house in keeping with his growing affluence and attended to his flourishing medical practice. His prestige was further enhanced when Charles V, on abdication from the Spanish throne in 1556, provided him with a lifetime pension and made him a count.

Vesalius went to Spain in 1559 with his wife and daughter to take up an appointment, made by Philip II, son of Charles V, as one of the physicians in the Madrid court. In 1564 Vesalius obtained permission to leave Spain to go on pilgrimage to the Holy Sepulchre. He traveled to Jerusalem, with stops at Venice and Cyprus, his wife and daughter having returned to Brussels.

Vesalius's work represented the culmination of the humanistic revival of ancient learning, the introduction of human
dissections into medical curricula, and the growth of a European anatomical literature. Vesalius performed his dissections with a thoroughness hitherto unknown. After Vesalius, anatomy became a scientific discipline, with far-reaching implications not only for physiology but for all of biology. During his own lifetime, however, Vesalius found it easier to correct points of Galenic anatomy than to challenge his physiological framework.

Conflicting reports obscure the final days of Vesalius's life. Apparently he became ill aboard ship while returning to Europe from his pilgrimage. He was put ashore on the Greek island of Zacynthus, where he died.

(b. Dec. 14, 1546, Knudstrup, Scania, Denmark—d. Oct. 24, 1601, Prague)

T
ycho Brahe was a Danish astronomer whose work in developing astronomical instruments and in measuring and fixing the positions of stars paved the way for future discoveries. His observations—the most accurate possible before the invention of the telescope—included a comprehensive study of the solar system and accurate positions of more than 777 fixed stars.