Friedrich Wilhelm Nietzsche (15 October 1844 – 25 August 1900) was a German philosopher and writer who started his career as a classical philologist and turned to philosophy early in his academic career. In 1869, at age 24, he was appointed Professor of Classical Philology at the University of Basel. Plagued by health problems for most of his life, he resigned from the university in 1879. He afterward lived as an independent writer, spending much of his life in relative solitude and financial insecurity while moving between Switzerland, Italy, and southern France in search of climates that might alleviate his condition, and in the following decade, he completed much of his core writing. In 1889, aged 44, he suffered a neurological collapse, and thereafter a complete loss of his mental faculties, with paralysis and vascular dementia; he lived out his remaining 11 years, first under the care of his mother, and later his sister, until his death. His works and his philosophy have fostered not only extensive scholarship but also much popular interest. Nietzsche's work encompasses poetry, cultural criticism, and philosophical essays while displaying a fondness for aphorisms and irony. Prominent elements of his philosophy include his critique of objective truth in favour of perspectivism; a genealogical critique of Christian morality and a related theory of master–slave morality; the affirmation of life in response to both the weakening of religion ("God is dead") and the crisis of passive nihilism which followed it; the notion of Apollonian and Dionysian duality; and a characterisation of the human subject as the expression of competing wills, collectively understood as the will-to-power. His later work developed influential concepts such as the Übermensch, the transvaluation of values, and his unique formulation of eternal return. His body of work touched a wide range of topics, including aesthetic, philology, history, music, religion, tragedy, culture and science, and drew inspiration from such diverse sources as Greek tragedy, Arthur Schopenhauer, Ralph Waldo Emerson, and Richard Wagner. After Nietzsche's death, his sister, Elisabeth Förster-Nietzsche, became the curator and editor of his manuscripts. She edited his unpublished writings to fit her German ultranationalist ideology, often contradicting or obfuscating Nietzsche's stated opinions, which were explicitly opposed to antisemitism and nationalism. Through her published editions, Nietzsche's work became associated with fascism and Nazism. Twentieth-century scholars such as Walter Kaufmann, R. J. Hollingdale and Georges Bataille defended Nietzsche against this interpretation, and corrected editions of his writings were soon made available. His works enjoyed renewed popularity in the 1960s and his ideas have since had a widespread impact on 20th- and 21st-century thinkers across philosophy—especially in schools of continental philosophy such as existentialism, postmodernism and post-structuralism—as well as art, literature, music, poetry, politics and popular culture.