Linnaeus had to manage a conflict between the need to bring information into a fixed order for purposes of later retrieval, and the need to permanently integrate new information into that order, says Mueller-Wille. “His solution to this dilemma was to keep information on particular subjects on separate sheets, which could be complemented and reshuffled,” he says.

Towards the end of his career, in the mid-1760s, Linnaeus took this further, inventing a paper tool that has since become very common: index cards. While stored in some fixed, conventional order, often alphabetically, index cards could be retrieved and shuffled around at will to update and compare information at any time.

“Although a seemingly mundane and simple innovation, Linnaeus’ use of index cards marks a major shift in how eighteenth-century naturalists thought about the order of nature,” says Mueller-Wille. The natural world was no longer ordered on a fixed, linear scale, but came to be seen as a map-like natural system of multiple affinities.

Index cards: the original database.

via boingboing