Full Idea
The view that evil is an illusion is self-refuting: that is, if there is no evil, the illusion that there is evil is certainly evil.
Gist of Idea
Evil can't be an illusion, because then the illusion that there is evil would be evil
Source
Robin Le Poidevin (Intro to 'Questions of Time and Tense' [1998], 2)
Book Reference
'Questions of Time and Tense', ed/tr. Le Poidevin,R [OUP 2002], p.4
A Reaction
[The idea comes from McTaggart, and Le Poidevin is quoting Dummett on it]