Friedrich Nietzsche (1844-1900) was a German philosopher whose works critique the entire philosophical tradition up to this point, and provocatively call for a reaffirmation of life that has been sacrificed for the sake of abstract knowledge. Often considered the first existentialist philosopher who proclaimed "the death of God," his work was largely ignored during his lifetime but had an incalculable influence on modern politics, philosophy, psychology, and culture, including its many appropriations by both right-wing and left-wing movements.