On the Genealogy of Morals is an 1887 philosophical treatise by Friedrich Nietzsche about the origins of morality. In the first part of the book, Nietzsche describes the difference between a noble, selfish moral spectrum of good versus bad and a spectrum of "slave morality" between good and evil. Nietzsche argues that this latter spectrum developed through Judaism and Christianity and has since battled the former. Later, Nietzsche examines the origins of punishment and its development into guilt, self-abasement and "ascetic ideals" he finds harmful.
Thus Spoke Zarathustra is a philosophical text by Friedrich Nietzsche told as a series of parables and declarations by the traveling prophet Zarathustra. The treatise was published in four parts from 1883 to 1885 and concerns Nietzche's concept of the ubermensch, or overman, a superior being that man must become through self-overcoming and by expressing his inner will to power. Like many of Nietzsche's works, Thus Spoke Zarathustra contains harsh critiques of Christian morality, declaring famously that "God is dead."