I show that we have reason to believe a view on scientific theory change can be discerned in what I call the “Copernicus passages” of Nietzsche’s published work—specifically, the incommensurability thesis. Since this view denies what Maudemarie Clark calls the “equivalence principle,” she claims incommensurability cannot reasonably be attributed to Nietzsche. I argue, however, that we can reasonably attribute incommensurability to Nietzsche in the Copernicus passages, so my reading should not be ruled out. The first upshot to this project is that I provide a reading of passages that have received no scholarly attention to date. The second upshot is that we can understand Copernicus in light of the broader, better-known themes in Nietzsche’s published work: Nietzsche’s moral skepticism about the value of self-denial motivates his opposition to the ascetic ideal and to the emerging dogmas of scientists.