Abstract. In the Alps, folds were recognized in the early eighteenth century, thrusts in the middle of the nineteenth century. The nappe theory, developed from 1884 to 1902, led to a mobilistic approach, implying large-scale relative movements of Europe and of a prong of Africa (Argand, Staub). The existence of Mesozoic oceans or ocean-like basins was also realized. Ampferer introduced the concept of subduction (Verschluckung). Around 1935, Alpine geologists somehow became afraid of their own courage, and failed to present a coherent interpretation of the structure and evolution of the chain. The theory of plate tectonics was developed primarily by geophysicists at sea, who took little account of the Alpine evidence.