The tenth edition of this book (1758) is considered the starting point of zoological nomenclature. In 1766–1768 Linnaeus published the much enhanced 12th edition, the last under his authorship. Another again enhanced work in the same style and entitled "Systema Naturae" was published by Johann Friedrich Gmelin between 1788 and 1793. Since at least the early 1900s zoologists commonly recognized this as the last edition belonging to this series. It was also officially regarded by the ICZN in Opinion 296 (26 Oct 1954) as the 13th edition of Systema Naturae.
Linnaeus (later known as "Carl von Linné", after his ennoblement in 1761) published the first edition of Systema Naturae in the year 1735, during his stay in the Netherlands. As was customary for the scientific literature of its day, the book was published in Latin. In it, he outlined his ideas for the hierarchical classification of the natural world, dividing it into the animal kingdom (regnum animale), the plant kingdom (regnum vegetabile), and the "mineral kingdom" (regnum lapideum).
Linnaeus's Systema Naturae lists only about 10,000 species of organisms, of which about 6,000 are plants and 4,236 are animals. According to the historian of botany William T. Stearn, "Even in 1753 he believed that the number of species of plants in the whole world would hardly reach 10,000; in his whole career he named about 7,700 species of flowering plants."
Linnaeus developed his classification of the plant kingdom in an attempt to describe and understand the natural world as a reflection of the logic of God's creation. His sexual system, where species with the same number of stamens were treated in the same group, was convenient but in his view artificial. Linnaeus believed in God's creation, and that there were no deeper relationships to be expressed. He is frequently quoted to have said: "God created, Linnaeus organized" (Latin: Deus creavit, Linnaeus disposuit). The classification of animals was more natural. For instance, humans were for the first time placed together with other primates, as Anthropomorpha.
As a result of the popularity of the work, and the number of new specimens sent to him from around the world, Linnaeus kept publishing new and ever-expanding editions of his work. It grew from eleven very large pages in the first edition (1735) to 2,400 pages in the 12th edition (1766–1768). Also, as the work progressed, he made changes: in the first edition, whales were classified as fishes, following the work of Linnaeus' friend and "father of ichthyology" Peter Artedi; in the 10th edition, published in 1758, whales were moved into the mammal class. In this same edition, he introduced two-part names (see binomen) for animal species, something that he had done for plant species (see binary name) in the 1753 publication of Species Plantarum. The system eventually developed into modern Linnaean taxonomy, a hierarchically organized biological classification.
After Linnaeus' health declined in the early 1770s, publication of editions of Systema Naturae went in two directions. Another Swedish scientist, Johan Andreas Murray issued the Regnum Vegetabile section separately in 1774 as the Systema Vegetabilium, rather confusingly labelled the 13th edition. Meanwhile, a 13th edition of the entire Systema appeared in parts between 1788 and 1793. It was as the Systema Vegetabilium that Linnaeus' work became widely known in England following translation from the Latin by the Lichfield Botanical Society, as A System of Vegetables (1783–1785).
In his Imperium Naturæ, Linnaeus established three kingdoms, namely Regnum Animale, Regnum Vegetabile and Regnum Lapideum. This approach, the Animal, Vegetable and Mineral Kingdoms, survives until today in the popular mind, notably in the form of parlour games: "Is it animal, vegetable or mineral?". The classification was based on five levels: kingdom, class, order, genus, and species. While species and genus was seen as God-given (or "natural"), the three higher levels were seen by Linnaeus as constructs. The concept behind the set ranks being applied to all groups was to make a system that was easy to remember and navigate, a task which most say he succeeded in.