Friedrich Nietzsche (1844-1900) was a German philosopher known for his critiques of traditional values and beliefs. He emphasized individualism and the affirmation of life, while rejecting conventional morality. In his works, he questioned religion, morality, and truth's role in society. Nietzsche introduced the concept of the "will to power" and famously declared, "God is dead." His ideas significantly influenced existentialism, postmodernism, and the development of psychoanalysis.