Missions were not simply sites of modernity, they were also the source of key data for the modernist theories of human progress. The idea that so called “primitive peoples” provided a window to the origins of human institutions seemed axiomatic to nineteenth-century theorists of human society who sought evidence for these ideas from settlers, administrators and particularly missionaries. The 1870s and 1880s were the high point of missionary engagement with study-bound anthropologists, as questionnaires and letters were sent from the centres to the edges of empires. Missionary responses, augmented with settler and explorer observations, became the footnotes in early anthropological texts on “primitive” societies. These analyses were then mined for the foundation texts of the other social sciences in the late nineteenth century. Along with many other scholars, Karl Marx and Friedrich Engels read the anthropology of the period and slotted the findings into their analyses of human society.