Linnaeus and Systema Naturae (1735): Naming the Living World

Systema Naturae (“The System of Nature”) is the classification of the natural world first published by the Swedish naturalist Carl Linnaeus in Leiden in 1735. Its ranked scheme of classes, orders, genera and species, and Linnaeus’s later habit of giving every species a two-part Latin name, became the basis of the way scientists still name living things. Few short publications have shaped a whole science so lastingly.

Background: a flood of new species

By the early eighteenth century European naturalists were overwhelmed by specimens. Voyages to the Americas, Africa and Asia had brought back thousands of plants and animals unknown to ancient authors, and there was no agreed way to sort or name them.

Species were usually identified by descriptive Latin phrases, sometimes a dozen words long, that changed from one author to another. Earlier botanists such as John Ray and Joseph Pitton de Tournefort had proposed systems, but none was accepted everywhere.

Carl Linnaeus was born on 23 May 1707 at Råshult in the province of Småland, southern Sweden, the son of a Lutheran pastor and keen gardener. He studied medicine and botany at Lund and then Uppsala, and in 1732 made a five-month expedition to Lapland, recording plants, animals and the life of the Sami people.

The first edition of 1735

In 1735 Linnaeus travelled to the Dutch Republic, then a centre of medicine and natural history, and took a medical degree at the University of Harderwijk in June. In Leiden he showed his manuscript to the botanist Jan Frederik Gronovius, who, with the Scottish physician Isaac Lawson, paid for it to be printed.

The first edition of Systema Naturae was strikingly brief: a set of large folio sheets laid out as tables, usually described as eleven pages of text. It divided nature into three kingdoms, animal, vegetable and mineral, each split into classes, orders and genera.

For plants Linnaeus used his “sexual system”, based on the reproductive parts of flowers. The number, length and arrangement of the stamens decided the class; the pistils decided the order. With a hand lens, a student could place an unfamiliar plant in one of 24 classes.

Among the animals, Linnaeus placed human beings, under the genus Homo, in an order he called Anthropomorpha alongside apes and sloths. Many readers found this provocative, but he defended it on the ground that he could find no anatomical feature that clearly separated people from apes.

Binomial names

The two-part name, or binomial, is Linnaeus’s best-known legacy, but it did not appear fully formed in 1735. He first used it consistently for all plants in Species Plantarum (1753) and for all animals in the much enlarged 10th edition of Systema Naturae (1758).

Each species received the name of its genus followed by a single descriptive word, the specific epithet: Quercus robur for the English oak, Canis lupus for the wolf. Linnaeus at first saw these as convenient short labels alongside the longer phrase descriptions, but they proved so practical that they replaced them.

The 10th edition also introduced the name Homo sapiens and the class Mammalia, defined by the mammary glands. Species Plantarum (1753) and the edition of 1758 remain the formal starting points of botanical and zoological naming respectively today.

Linnaeus at Uppsala and his apostles

Linnaeus spent about three years in the Netherlands. He worked for the wealthy banker George Clifford at his estate, De Hartekamp, cataloguing its garden and menagerie, and published Genera Plantarum (1737) and Flora Lapponica (1737). He returned to Sweden in 1738, practised as a physician in Stockholm, and in 1739 was a founder and first president of the Royal Swedish Academy of Sciences.

In 1741 he became a professor at Uppsala University, where he directed the botanical garden now restored as the Linnaean Garden. His lectures and field excursions drew large numbers of students.

Linnaeus encouraged his best students, later called his “apostles”, to collect abroad. Pehr Kalm travelled in North America (1747–1751), Pehr Osbeck sailed to China, Fredrik Hasselquist explored Egypt and Palestine, and Carl Peter Thunberg worked in southern Africa and Japan. Daniel Solander sailed on Cook’s first voyage, and Anders Sparrman joined the second. Several apostles, including Hasselquist, Pehr Löfling and Peter Forsskål, died on their journeys.

Criticism and reception

The sexual system was popular because it was simple, but critics noted that it was artificial: it grouped plants by a single feature rather than their overall similarity. The German botanist Johann Georg Siegesbeck also attacked it as indecent for describing flowers in terms of marriages and partners.

In France, the naturalist Georges-Louis Leclerc, comte de Buffon, rejected rigid classification altogether, arguing that nature shades gradually from one form into another. Over time, botanists such as Antoine-Laurent de Jussieu developed natural systems that replaced Linnaeus’s classes, even as his naming method survived.

Despite such objections, the system spread quickly through Europe and its colonies. It suited the age: amateur collectors, physicians and missionaries could identify plants and send specimens with names that experts elsewhere would understand, and Linnaeus’s correspondence network stretched from Russia to North America.

Linnaeus was ennobled in 1761, taking the name Carl von Linné. He died in Uppsala on 10 January 1778.

Legacy

Linnaeus believed he was revealing the order of a fixed creation, and he did not think in terms of evolution. Yet his nested hierarchy of groups within groups gave later naturalists a framework that Charles Darwin could explain as the result of common descent.

His collections were bought in 1784 by the English naturalist James Edward Smith and became the founding treasure of the Linnean Society of London, established in 1788. It was at that society that Darwin’s and Wallace’s theory of natural selection was first presented in 1858, as described in the Darwin–Wallace papers.

Modern codes of nomenclature for plants, animals, fungi and bacteria still use binomial names and ranks derived from Linnaeus, although genetic studies have reshaped many of the groups themselves.

Myths and facts

Myth: Linnaeus created the full modern ladder of ranks. He used kingdom, class, order, genus and species, with varieties below. The ranks of phylum and family were added by later naturalists in the eighteenth and nineteenth centuries.

Myth: Linnaeus invented two-part names. Earlier writers, including the Swiss botanist Caspar Bauhin, had sometimes used two-word names. Linnaeus’s achievement was to apply them to every known species and make them the standard.

Myth: Linnaeus chose himself as the model specimen of Homo sapiens. He never did. The idea comes from 1959, when the botanist William T. Stearn suggested that Linnaeus himself should serve as the reference specimen for the species, a proposal that has been debated since.

By the numbers

Timeline

• 1707, 23 May: Carl Linnaeus is born at Råshult, Småland, Sweden.
• 1732: Linnaeus makes his expedition to Lapland.
• 1735: He takes a medical degree at Harderwijk and publishes Systema Naturae in Leiden.
• 1738: He returns to Sweden.
• 1741: He becomes a professor at Uppsala University.
• 1753: Species Plantarum applies binomial names to all known plants.
• 1758: The 10th edition of Systema Naturae applies them to animals.
• 1778, 10 January: Linnaeus dies in Uppsala.

Why it matters

Linnaeus gave biology a common language. By insisting that every species have one short, stable name and a place in a ranked system, he made it possible for naturalists across the world to share information reliably, a convention that still governs the naming of new species today.