This paper is a reaction to ‘Styles of Thought on the Continental Drift Debate’ by Pablo Pellegrini, published in this journal. The author argues that rationalist accounts of the continental drift debate fail because they overlook important issues. In this discussion we distinguish various forms of rationalism. Then we present a sophisticated rationalist account of the continental drift debate and argue that it is satisfactory because it explains all the central developments in that debate. Finally, we point to a problematic tension in Pellegrini’s paper and unravel an underlying ambiguity.