Aby Warburg, a member of the wealthy Hamburg banking family who devoted his life instead to art history and cultural scholarship, spent decades assembling a private library organized not by conventional subject headings but by what he called the law of the good neighbor, shelving books together according to the associative connections between the ideas they addressed rather than strict disciplinary categories, a system meant to encourage unexpected intellectual connections during research. Warburg's scholarship focused increasingly on how the imagery, symbols and ideas of classical antiquity survived and were transformed as they passed through medieval and Renaissance culture, a subject that led him deep into the history of astrology, magic and divination as vehicles through which ancient ideas persisted into later periods.
Warburg suffered a severe psychological breakdown during and after the First World War and spent several years in a Swiss psychiatric clinic, during which his assistant Fritz Saxl took charge of the library and, in 1921, formally reorganized it as a research institute, the Kulturwissenschaftliche Bibliothek Warburg, giving Warburg's idiosyncratic collection and method an institutional structure with a permanent staff and a program of publication and public lectures. Warburg himself resumed direction of the library after his recovery and continued to lead it until his death in 1929, by which time the Hamburg institute had become an internationally recognized center for the study of cultural and intellectual history using methods Warburg had pioneered.