Full Idea
Morality acts to prevent the rise of new and better mores: it stupefies.
Gist of Idea
Morality prevents us from developing better customs
Source
Friedrich Nietzsche (Dawn (Daybreak) [1881], 019)
A Reaction
Note that he wants 'better' customs, and not just different ones. So the deep question concerns the criteria for why some customs are better. He seems to want us to fulfil our natures more completely. Arts, sciences, great deeds...
Book Reference
Nietzsche,Friedrich: 'Dawn (Daybreak) (v 5)', ed/tr. Smith, Brittain [Stanford 2011], p.20