Arthur Schopenhauer traveled in childhood throughout Europe and lived for a time in Goethe's Weimar, where his mother had established a salon that attracted many of Europe's leading intellectuals. As a young man, Schopenhauer studied at the University of Gottingen and in Berlin, where he attended the lectures of Fichte and Schleiermacher. Schopenhauer's first work was The Fourfold Root of the Principle of Sufficient Reason (1813), followed by a treatise on the physiology of perception, On Vision and Colors (1816). When Schopenhauer wrote his principal work, The World as Will and Idea (1819), he was confident that it was a work of great importance that would soon win him fame, but in this he was badly disappointed. In 1819 he arranged to hold a series of philosophical lectures at the same time as those of the newly arrived professor Hegel, whom Schopenhauer despised (calling him, among other creative epithets, an "intellectual Caliban"). This move resulted only in further humiliation for Schopenhauer, since no one showed up to hear him. Schopenhauer continued to be frustrated in repeated attempts to achieve recognition. In 1839 and 1840 he submitted essays on freedom of the will and the foundation of morality to competitions sponsored by the Royal Danish Academy but he won no prize, even when his essay was the only entry in the competition. In 1844 he published a second volume of The World as Will and Idea, containing developments and commentaries on the first. Around 1850, toward the end of his life, Schopenhauer's philosophy began to receive belated recognition, and he died in the confidence that his long-awaited and deserved fame had finally come. Schopenhauer's philosophy exercised considerable influence in the late nineteenth and early twentieth centuries, not only among academic philosophers but even more among artists and literati. This may be in part because, unlike his German idealist contemporaries, Schopenhauer is a lucid and even witty writer, whose style consciously owes more to Hume than to Kant. Schopenhauer's philosophy is founded on the idea that reality is Will--a single, insatiable, objectless striving that manifests itself in the world of appearance as a vast multiplicity of phenomena, engaged in an endless and painful struggle with one another. He saw the same vision in the texts of Indian religions---Vedanta and Buddhism---which he regarded as vastly superior to Western monotheism. Schopenhauer's theory of the empirical world is an idealism, in which the doctrines of Kant are identified with those of Berkeley. In aesthetic enjoyment Schopenhauer saw a form of knowledge that is higher than ordinary empirical knowledge because it is a disinterested contemplation of the forms or essences of things, rather than a cognition of causal connections between particulars driven by the will's interest in control and domination. True salvation, however, lies in an intuitive insight into the evil of willing, which in its highest manifestations is capable of completely extinguishing the will in a state of nirvana. In his perceptive development of the psychological consequences of his theory, Schopenhauer gives particular emphasis to the way in which our knowledge and behavior are insidiously manipulated by our unconscious volition; this stress, plus the central role he gives to sexuality in his theory of the will, contains much that is found later in Freud (who acknowledged that Schopenhauer had anticipated his theory of repression). Schopenhauer's main influence on twentieth-century philosophy, however, was mediated by Nietzsche, whose theory of the will to power added a poignant twist by committing itself to the affirmation of the will while still conceiving it in essentially the same way---insatiable, painful, predatory, deceptive, and subversive of rational thought---which it had been in Schopenhauer's metaphysical pessimism.