Where it comes from. The commonplace book descends from the florilegium, the 'gathering of flowers' — collections of extracts compiled from the eighth century onward, arranged chronologically at first and under thematic headings by the thirteenth. Renaissance humanists made the practice standard, and it stayed standard from then into the Enlightenment. Its ancestry is rhetorical: the classical loci communes, the common places from which arguments were drawn.

Locke's contribution. Locke began keeping one as an Oxford undergraduate in 1652 and spent the next decade refining an indexing method. He wrote it up in French in the mid-1680s for the scholarly press; the English version, A New Method of Making Common-Place-Books, was published in 1706, after his death. Sources differ over whether the French text appeared in 1685, 1686 or 1687, and the honest position is that the exact year is unsettled — the English date is not.

Why the index is the invention. Every other scheme allocates space by subject in advance and therefore has to guess how much each subject will need. Locke's separates storage from retrieval: pages are filled in the order they are used, and a fixed-size index maps subjects to positions. It is the same argument as an index in a database, three hundred years early, and it is why blank books were later sold pre-ruled to his design.

Who kept them. The habit was near-universal among the literate: Linnaeus used commonplacing while developing his classification, and Newton, Erasmus Darwin, Charles Darwin and Virginia Woolf all kept collections. They are not diaries. A commonplace book records what was worth keeping from outside, not what happened to you — which is exactly why they remain useful to read.

Scrapbooking

Blueprints (1)

Commonplace Book