The cultural historian Aby Warburg used reproductive images, predominantly photography, but also plaster casts, in many of his projects, most famously in the Mnemosyne picture atlas. His most extensive discussion of plaster casts is published here for the first time in the form of a parliamentary transcript of his statement before a committee of his home town’s legislative body, the Hamburger Bürgerschaft, in December 1909. Here Warburg speaks in favour of the appointment of a classical archaeologist, whose duties he presents as mainly to be concerned with the city’s neglected collection of classical casts. Drawing on an array of sources from Warburg’s correspondence and working papers, the article analyses Warburg’s perception of classical cast collections and plaster casts in general. Subscribing in part to the ideals of German eighteenth-century thinkers such as Winckelmann and Lessing, Warburg identified these collections as major sources of the Enlightenment and attributed to them an important role in German classical school education, where these images would complement study of ancient texts. However, Warburg was by no means a great admirer of the impressive cast collections of his time: only a few years after completing his studies he ascribed his perceived inability to react spontaneously to ancient sculpture and monuments to the ‘so-called classical plaster shop talk’ of his school and student days. For Warburg, casts after ancient sculpture had to be complemented with other non-classical imagery and needed to have ‘life breathed into them’ in order to affect the beholder.