lectures tedious and hard to understand. He later mentioned Fichte only in critical, negative terms—seeing his philosophy as a lower-quality version of Kant's and considering it useful only because Fichte's poor arguments unintentionally highlighted some failings of Kantianism. He also attended the lectures of the famous Protestant theologian Friedrich Schleiermacher, whom he also quickly came to dislike. His notes and comments on Schleiermacher's lectures show that Schopenhauer was becoming very critical of religion and moving towards atheism. He learned by self-directed reading; besides Plato, Kant and Fichte he also read the works of Schelling, Fries, Jacobi, Bacon, Locke, and much current scientific literature. He attended philological courses by August Böckh and Friedrich August Wolf and continued his naturalistic interests with courses by Martin Heinrich Klaproth, Paul Erman, Johann Elert Bode, Ernst Gottfried Fischer, Johann Horkel, Friedrich Christian Rosenthal and Hinrich Lichtenstein (Lichtenstein was also a friend whom he met at one of his mother's parties in Weimar). Early work Schopenhauer left Berlin in a rush in 1813, fearing that the city could be attacked and that he could be pressed into military service as Prussia had just joined the war against France. He returned to Weimar but left after less than a month, disgusted by the fact that his mother was now living with her supposed lover, Georg Friedrich Konrad Ludwig Müller von Gerstenbergk (1778–1838), a civil servant twelve years younger than her; he considered the relationship an act of infidelity to his father's memory. He settled for a while in Rudolstadt, hoping that no army would pass through the small town. He spent his time in solitude, hiking in the mountains and the Thuringian forest and writing his dissertation, On the Fourfold Root of the Principle of Sufficient Reason. He completed his dissertation at about the same time as the French army was defeated at the Battle of Leipzig. He became irritated by the arrival of soldiers in the town and accepted his mother's invitation to visit her in Weimar. She tried to convince him that her relationship with Gerstenbergk was platonic and that she had no intention of remarrying. But Schopenhauer remained suspicious and often came in conflict with Gerstenbergk because he considered him untalented, pretentious, and nationalistic. His mother had just published her second book, Reminiscences of a Journey in the Years 1803, 1804, and 1805, a description of their family tour of Europe, which quickly became