Disseminated by biblical and classical sources (and by Aristotle in particular), the image of an uncultivated, barbarian north shaped medieval socio-geography. Based on climatic considerations, it seemed obvious that these cold zones did not allow for the establishment of civilization and rationality. At the end of the Middle Ages, however, Scottish intellectuals who were embarrassed by this prevailing image started to defy it. In order to inscribe themselves into the realm of European civilization, they presented, on the one hand, a sometimes quite creative reshaping of the climatic scheme. On the other hand, they reinforced an alternative explanation for cultural differences and varying states of rationality, resorting to a conception of different natures within the human species. After introducing two exponents of these developments in the 16th century ( John Mair and Hector Boece), this paper turns to the Scottish Enlightenment of the late 18 th century. Focusing on David Hume and Adam Ferguson, it describes how these same two arguments, based on either climate or inherent nature, still governed the discussion about different states of civilization in this period, the latter alternative having now been developed into a full-fledged theory of race.