Natural History, encyclopaedic scientific work of dubious accuracy by Pliny the Elder, completed in 77 ce as Naturae historiae and conventionally known as Naturalis historia.
Although Pliny did not distinguish between fact, opinion, and speculation in his 37-volume treatise, he can be credited with the creation of the first scientific encyclopaedia. For centuries the Natural History served as the Western world’s primary source of scientific information and theory.
Book I summarizes the entire contents of the work, listing the authors and sometimes the titles of the books (many of which are now lost) from which Pliny derived his material. Book II is devoted to astronomy; Books III through VI, geography; VII through XI, zoology; XII through XIX, botany—and it is here that Pliny made his most substantial scientific contribution; XX through XXXII, medicine, including many moralistic comments on the deleterious effects of high living; and XXXIII through XXXVII, geology and mineralogy.
Niccolò Leoniceno’s 1492 tract on the errors of Pliny was the first of several works questioning the accuracy and usefulness of the Natural History. By the end of the 17th century, as the scientific method of empirical observation replaced speculation, the work had been superseded.