Arthur Schopenhauer ( SHOH-pən-how-ər, German: [ˈaɐtʊɐ ˈʃoːpm̩haʊɐ] (listen); 22 February 1788 – 21 September 1860) was a German philosopher. He is best known for his 1818 work The World as Will and Representation (expanded in 1844), which characterizes the phenomenal world as the product of a blind noumenal will. Building on the transcendental idealism of Immanuel Kant (1724–1804), Schopenhauer developed an atheistic metaphysical and ethical system that rejected the contemporaneous ideas of German idealism. He was among the first thinkers in Western philosophy to share and affirm significant tenets of Indian philosophy, such as asceticism, denial of the self, and the notion of the world-as-appearance. His work has been described as an exemplary manifestation of philosophical pessimism.

Though his work failed to garner substantial attention during his lifetime, Schopenhauer had a posthumous impact across various disciplines, including philosophy, literature, and science. His writing on aesthetics, morality, and psychology have influenced many thinkers and artists. Those who have cited his influence include philosophers Emil Cioran, Friedrich Nietzsche and Ludwig Wittgenstein, scientists Erwin Schrödinger and Albert Einstein, psychoanalysts Sigmund Freud and Carl Jung, writers Leo Tolstoy, Herman Melville, Thomas Mann, Hermann Hesse, Machado de Assis, Jorge Luis Borges, Marcel Proust and Samuel Beckett, and composers Richard Wagner, Johannes Brahms, Arnold Schoenberg and Gustav Mahler.