This chapter explores how the arrangement of Douce’s collections was determined by past and current systems of classification. Douce’s interest in natural history made him familiar with the methods and practices that characterised the eighteenth-century culture of curiosity and with Linnaean taxonomy. He also tried to apply this system to the visual materials in his collections. In the early nineteenth century, paradigm shifts in the arrangement and display of art collections influenced how Douce classified part of his prints and drawings. Discoveries in geology and palaeontology, two disciplines in which Douce was also interested, provided early nineteenth-century scholars with a new sense of historical time, which ought to be reconciled with existing systems of natural history classification. Contemporary developments in the philosophy of history, of which Douce was aware through his networks, complicated his efforts at systematising and classifying his materials further.