Nietzsche said your morals were written by the losing side
In 1886 he proposed a strange genealogy: our deepest ethical convictions may have been engineered by people who had no other weapon.
Nietzsche drew a line between two systems of value he called master morality and slave morality. The masters — ancient warriors and aristocrats — started from a single question: what is strong, vital, excellent? Whatever matched that answer was good; whatever was weak was merely bad, with no real condemnation attached.
The slaves had no swords. Their weapon was redefinition. Gradually, over centuries, they inverted the whole vocabulary. The master's strength became evil. Humility, which had once been forced on them, became a virtue freely chosen. The patient, the meek, the harmless: these were now the good ones.
Nietzsche called the emotional engine behind this reversal ressentiment — a French word he kept in French, as though even the language should mark it foreign: a festering resentment that cannot strike directly and so strikes through ideas. In Beyond Good and Evil (1886), he argued that democratic politics and Christian ethics both carry this same buried inheritance.
This is not a comfortable argument, and Nietzsche never pretended it was. His point was not that cruelty is good. It was something stranger: that we have inherited a moral vocabulary from people whose primary motive was not love of goodness but hatred of power, and that we rarely stop to notice.
Asking where a value came from is not the same as saying the value is wrong. But it is a more unsettling question.