•Why it earns a slot
The Genealogy of Morals is the most sustained and analytically rigorous of Nietzsche's works, providing the historical and psychological argument behind his transvaluation of values and directly shaping twentieth-century debates in ethics, psychology, and the critique of religion.
Nietzsche traces the historical origins of moral concepts such as 'good,' 'evil,' 'guilt,' and 'bad conscience,' arguing that dominant morality did not arise from timeless truths but from power struggles between aristocratic and slave classes. He contends that the 'slave revolt in morality,' driven by resentment, inverted aristocratic values and eventually triumphed through Christianity, poisoning European culture with life-denying ideals. The third essay extends this critique to ascetic ideals, showing how priests exploit human suffering to maintain power, and concludes that even modern science remains secretly in thrall to the ascetic will to truth.
This distillation is written from the freely available original, which is always the better read when you have the time: gutenberg.org.