LinnÉ, Carl von (1707-1778)

Swedish physician and botanist

Carl von Linné (Linnaeus) decisively broke through centuries of confusion over how to revise the classification system that had been in place since antiquity. With few parallels in the history of science, Linnaeus's contribution to botany will remain intact perhaps as long as the first classification system.

Linnaeus was born in Stenbrohult, Sweden. His father, a clergyman, maintained a small botanical garden on the parsonage grounds, where Linnaeus earned the nickname "little botanist." In 1716, Linnaeus entered a Latin school and began to formalize his interest in botany and the natural sciences. In 1727, he transferred to the University of Lund to study medicine, but he also undertook extensive botanical excursions. One year later, he went on to the University of Uppsala, which was considered a better school for medicine, but Linnaeus was disappointed to find that its facilities were no better than those at the University of Lund. Nevertheless, Uppsala did have something that made up for the shortcoming, a botanical garden containing rare foreign plants.

As his academic ideas started to mature along with his research, Linnaeus constructed a new theory of plant sexuality. In 1735, he published his System Naturae, and two years later, Genera Planetarum. He also moved briefly to Holland, where he received his M.D. In 1739, Linnaeus began to practice medicine, and two years later, he became the chair of botany, dietetics, and materia medica at the University of Uppsala. For the rest of his life, Linnaeus remained in this position, while his fame as a premier botanist spread throughout the world because of his influence in revising the 2,000-year-old system of classification.

The philosopher Aristotle had devised the first classification system over 2,000 years earlier, when he established the basic principles of dividing and subdividing plants and animals. At that time, only about a thousand species were known. Therefore, he grouped them into simple categories of animals with backbones and animals without backbones. Plants were divided into different categories that dealt more with size and appearance. By the sixteenth century, however, the system was proving to be less and less adequate as the body of knowledge of plants and animals grew. Modification came slowly, often marked with debate and controversy, succeeding only in revealing the complexity of the process. In 1753, Linnaeus published his Species Planetarium, in which he replaced the antiquated Aristotelian system with the principles of classification used today.

In creating his system, Linnaeus's primary consideration was the number of observable characteristics of the organism, specifically its anatomy, structures, and details of reproduction. Based on his observations, Linnaeus created a hierarchical system in which living things were grouped according to their similarities, with each succeeding level possessing a larger number of shared traits. He named these levels class, order, genus, and species.

Linnaeus also popularized binomial nomenclature, giving each living thing a Latin name consisting of its genus and species, which distinguished it from all other organisms. For example, the cougar received the scientific name Felis concolor, while the lion became Panthera leo. This system allowed scientists to communicate worldwide about organisms without having to understand different languages. Also, each type of organism can be fitted into the scheme in a logical and orderly manner, allowing for infinite expansion. The various hierarchical levels in the system provide as well a conceptual framework for understanding the relationships among different organisms or groups of organisms.

Linnaeus's desire to classify all living things often bordered on the compulsive; he believed his work to be divinely inspired and considered those who did not follow his system to be "heretics." However, he was also a skilled and caring instructor who nurtured the interests of his many students, often sending them abroad to the Middle East, China, and the Pacific Islands for new specimens. In 1761, Linnaeus was given the noble title von Linné, and while the king of Spain offered him generous compensation to settle in his country, Linnaeus remained in Sweden at Uppsala until his death after a stroke in 1778.

Today an international commission of scientists maintains the Linnaeus classification system and adheres to the rules for adopting scientific names when newly discovered species or subspecies need to be classified. Although the system depends on the judgments and opinions made by biologists, its concept and general organization are accepted by scientists throughout the world.