Carl Linnaeus's botanical paper slips (1767–1773)

The development of paper-based information technologies in the early modern period is a field of enquiry that has lately benefited from extensive studies by intellectual historians and historians of science. How scholars coped with ever-increasing amounts of empirical knowledge presented in print and manuscript – leading to the so-called early modern “information overload” – is now being increasingly analysed and understood. In this paper we will turn to an example at the close of the early modern period. Towards the very end of his academic career, the Swedish naturalist Carl Linnaeus (1707–1778) – best known today for his “sexual” system of plant classification and his binomial nomenclature – used little paper slips of a standard size to process information on plants and animals that reached him on a daily basis. From today’s perspective, these paper slips look surprisingly like modern index cards. This is surprising, because throughout the early modern period, the medium of choice to cope with information overload was a different one: the commonplace book, promoted by humanists and philosophers such as Erasmus of Rotterdam (1466–1536), Francis Bacon (1561–1626), and John Locke (1632–1704). Commonplace books usually took the form of bound manuscripts that were subdivided by headings indicating the particular topics under which information was to be subsumed. The collected information was thus brought into a fixed and permanent order, and an index was usually added at the end of the volume to provide access to this information. One of the areas where information overload made itself felt in particular, and for which the commonplace book was adopted quickly, was natural history. As new worlds were discovered, and more species described, the circulation of information grew rapidly, in print and manuscript. Naturalists like Conrad Gessner (1516–1565) and Ulisse Aldrovandi (1522–1605) collected observations from specimens, annotated and excerpted new publications, and engaged in far-flung correspondence networks, all along developing their own common-placing techniques to process the information thus gained. In the process, some scholars and naturalists occasionally strove to find more flexible ways of accessing, storing, and retrieving information than the bound and structured commonplace book. One such way was processing and communicating information in the form of simple, open-ended lists of key words or short factual statements. Another, even more flexible way was to keep notes on loose pieces of papers, which enabled information to be shuffled around, collated, and rearranged readily. Thus Robert Boyle (1627–1691) kept his notes in a haphazard way on loose sheets and paper slips, apparently to prevent others from making sense of them, while Gottfried Wilhelm Leibniz (1646–1716) preferred to order his loose notes according to a contraption