The French state expropriated an enormous quantity of cultural property from across Europe during the Wars of the Revolution and Napoleon, but much was returned in 1815 after the fall of the Empire. This article examines contemporary attitudes to the displacement of works of art, antiquities, scientific specimens, and rare books. The seizures were controversial: since they occurred at a time when plundering the vanquished was already considered questionable behaviour, they attracted opposition and needed to be justified. The article identifies the resulting repertoire of attitudes, arguing that this repertoire evolved with changing circumstances and was more varied than hitherto maintained. By situating this repertoire in a larger historical context, the article also reassesses the extent to which attitudes were derivative and innovative. It contends that the disputation as a whole did not amount to a decisive rupture in the treatment of foreign cultural property during wartime, but that it was nevertheless remarkable in two respects: concepts from hitherto unrelated subjects were applied to considerations about cultural property; and the perceived conditions under which cultural property could be legitimately transferred were revised.