De Camp wrote his first Pusadian tales under the influence of the scientific theory of geological gradualism which then held sway, which led him to reject the possibility of the island continent disappearing in a sudden cataclysm, as related by Plato. Later scientific discovery of the geological forces of plate tectonics have since precluded the possibility of an island continent ever having existed where he (and Plato) put it, regardless of the rate of destruction, rendering de Camp's gradualism as obsolete as Howard's catastrophism.
De Camp composed his earliest Pusadian stories under the influence of geological gradualism, a theory that was popular during that era. This led him to reject the idea of a sudden cataclysmic event causing the island continent’s disappearance as described by Plato. Later scientific findings about plate tectonics have shown that such an ancient landmass could not exist where De Camp and Plato believed it might be, rendering his gradualist theory obsolete alongside Howard's catastrophism.