Abstract

Alfred Wegener’s Theory of Continental Drift and its Rivals. Rational Disagreement and Rational Consensus in the Earth Sciences Alfred Wegener launched the idea of continental drift (lateral motion of continents on the earth) early in the 20th century. In the period 1915-1930 he did not succeed to convince his fellow earth scientist to leave behind their old permanentist or contractionist theories and adopt his new theory. In the second half of the 20th century – between 1960 and 1975 – continental drift quickly became the dominant theory in the earth sciences. In this paper I analyse both episode by means of methodological concepts developed by Larry Laudan. I argue that the disagreement in the early days as well as the quickly emerging consensus in the second period are rational.