In 1783, Mendelssohn asked Maimon to leave Berlin due to Maimon's open Spinozism. After a journey to Hamburg, Amsterdam and then back to Hamburg, he started attending the Gymnasium Christianeum in Altona. During his stay there he improved his knowledge of the natural sciences and his command of German. In 1785, Maimon left for Berlin (where he met Mendelssohn for the last time), then moved to Dessau, and then settled in Breslau, where he attempted to study medicine but eventually took up the position of a tutor.