Overview: Life Sciences and Medicine 1450-1699

Previous Period

There was relatively little interest expressed in the life sciences during the Middle Ages. However, several factors developed in the later medieval period that led to a renewed interest in the careful observation of nature on the part of Europeans. These factors were: the writings of the Greek philosophers whose work had been rediscovered in the late Middle Ages; the learning of Arab philosophers and physicians, which became known after the crusades; and the work of such European scholars as Roger Bacon (1220?-1292?) and Albertus Magnus (1200?-1280). All three of these groups had stressed the importance of investigating the natural world. With the close examination of nature and the striving for realism that marked the Renaissance, sciences such as anatomy and botany began to develop their modern forms. The invention of the printing press in the mid-fifteenth century made it possible to transmit this learning much more easily, thus setting the stage for significant developments in the life sciences and medicine during the Renaissance.

Anatomy

Unillustrated medieval anatomical texts simply copied the writings of classical scholars such as Galen (c. 130-c. 200), who based his work on the dissection of animals, not humans. By the fourteenth century, human dissections were becoming common in Italian universities and it became clear that Galen's descriptions were not always accurate. One of the most significant events in the study of anatomy was the publication in 1543 of Andreas Vesalius's (1514-1564) book on human anatomy, De humani corporis fabrica, which combined exquisite illustrations with a text that was a significant improvement on the anatomies passed down from ancient times.

Historians have suggested that the artist who illustrated Vesalius's text was influenced by the unpublished drawings in Leonardo da Vinci's (1452-1519) famous notebooks, drawings based on actual dissections. Many artists of the time, including da Vinci and Albrecht Dürer (1471-1528), were extremely interested in anatomy, as well as other aspects of nature; they painted and drew much more realistic and accurate images of plants and animals than had been created in the previous centuries.

The philosopher and natural scientist René Descartes (1596-1650) developed the influential idea that the human body was like a machine and that the body and the mind, which he thought was seated in the brain's pineal gland, were quite separate from each other. A number of other anatomists also studied the nervous system in the seventeenth century; for instance, Thomas Willis (1621-1675) investigated blood circulation in the brain. One of the most significant anatomical works of the seventeenth century was done by William Harvey (1578-1657), the first to accurately describe the human circulatory system, including the circulation of blood through the heart. This work led to further interest in circulation and to the first blood transfusions, which were attempted in the 1660s. There were also considerable advances made in other areas of anatomy. Bartolommeo Eustachio (1520?-1574) investigated the structure of the ear, Harvey and his teacher Girolamo Fabrici (1537-1619) worked on the developing embryo, and Vesalius's pupil Gabriele Falloppio (1523-1562) studied the female reproductive system.

Medical Theories and Practices

In the sixteenth and seventeenth centuries medical practice remained a mixture of ancient ideas and new observations, with the latter leading to improved therapies. One of the individuals whose ideas represent such a mixture of old and new was Paracelsus (1493-1541), a Swiss alchemist and physician who argued against the barbaric, medieval techniques in medicine and called for radical change in medical practice, while at the same time holding to the ancient ideas of alchemy. These ideas led Paracelsus to encourage the use of chemicals such as sulfur and copper compounds as medicines, rather than the traditional plant-derived remedies.

Paracelsus was not the only physician developing new treatments at this time. Because there was little reliable information, there were numerous theories of disease. Many physicians, including some with very questionable remedies, preyed on people who were being assaulted by a large number of medical problems. Bubonic plague was still present in Europe, as was yellow fever, sweating sickness, leprosy, and a number of other infectious diseases. At the end of the fifteenth century, syphilis appeared in armies fighting in Italy and continued to spread throughout Europe in epidemic proportions for a long period of time.

Barber-surgeons were prominent dispensers of medical treatment, but during this time the field of surgery became more professionalized. The French surgeon Ambroise Paré (1510-1590) made many notable contributions to the field, including the practice of ligature, or tying off severed blood vessels. He also condemned the use of boiling oil as a treatment for gunshot wounds. In addition, there were changes in procedures related to childbirth. Traditionally babies had been delivered by female midwives, but with the increasing influence of surgeons, childbirth became the domain of these physicians, who were called "men-midwives."

All areas of medicine were enriched by the development of printing. Books called herbals gave information on the medicinal uses of plants, and many illustrated works of anatomy followed those of Vesalius. Printing also made possible wider distribution of ancient texts, and this led to more questioning of old ideas and to the search for better information. Medical manuals began to be produced in languages other than Latin, making knowledge more accessible to those with less education.

New Worlds

During the period 1450-1699, much of the activity in the life sciences resulted from the opening up of new worlds. The age of exploration was just beginning, and as explorers returned from voyages throughout the world, they often brought back both living and dead specimens of new plant and animal species, some of which were very unusual and had characteristics that had never been seen before by Europeans. Some plants soon became economically significant crops in Europe, including maize or corn and tobacco as well as potatoes and tomatoes. This wealth of new species brought questions of organization to the fore, and several classification schemes were developed, one of the most significant being that of the English botanist John Ray (1627-1705).

There was also an unintentional movement of species in the other direction as well, with those of the Old World being brought to the New World. For example, rats on European ships were responsible for the extinction of many species, particularly on islands where animals were not adapted to coping with rodent predators. Europeans also brought diseases to the lands they colonized, causing large-scale epidemics among native populations. Smallpox and other infectious diseases had arrived in the Caribbean by 1518 and they soon spread to Mexico and South America.

Another new world that opened up in the seventeenth century was the microscopic world, when magnifying lenses were perfected to the point that the tiny organisms in pond water and other fluids could be seen for the first time. In 1665 Robert Hooke (1635-1703) published Micrographia, a book which contained many drawings of specimens he had examined under the microscope, including a flea and the cells in a piece of cork. Jan Swammerdam (1637-1680) and Anton van Leeuwenhoek (1632-1723) were two Dutch naturalists who were particularly important in opening up this new microscopic world.

Botany and Zoology

Once the microscope was invented, it was used by a number of botanists, including Nehemiah Grew (1641-1712) and Marcello Malpighi (1628-1694), to investigate plant anatomy. In zoology, Konrad von Gesner (1516-1565) inaugurated the modern age of this science with a four-volume work on animals, published in the 1550s. The renewed interest in botany and zoology led to the establishment of a number of zoological and botanical gardens in Europe, which allowed the general public, for the first time, to be able to view organisms gathered from around the world.

The Future

By the time the seventeenth century ended, the life sciences were poised for the tremendous growth of knowledge that occurred in the eighteenth century. Work on classification, microscopic investigations, and anatomical studies all continued to bear fruit. There would also be more emphasis placed on experimentation, particularly in physiology, the study of plant and animal function.

ROBERT HENDRICK