Abstract
The 1950/51 UNESCO statements on race were opposed by a group of scientists who rejected the post-WWII scientifi c consensus that the human species does not divide neatly into races. Both sides of this dispute had explicit political purposes. The dispute turned on a difference between two models of the human species. Many accounts make model evaluation depend on the user's purposes. Applied to this case, such views render political the empirical question about whether races exist. This essay argues that there are empirical constraints on model use that are independent of and constrain the user's purposes.
