 Todd Calder has argued against the fixity thesis. Imagine that Darlene has a highly fixed disposition to perform evil actions that she does little to resist. Geoff also has a disposition to perform evil actions, but this disposition is not highly fixed because he is indifferent about whether he should be disposed to perform evil actions and is, in general, capricious and unprincipled. It isn’t clear that Darlene is an evil person while Geoff is not. If so, the characters of evil persons need not be highly fixed (Calder 2015b, 354).