June 3, 2005:
Good understands Evil; Evil is baffled by Good.
Two thousand years of consensus: in literature, in practice.
In part this is what makes Evil so easy to defeat. While Good can anticipate Evil's responses, Evil can never do the same.
Imagine this common interaction. Good person performs some thoughtful or kind action. Evil person responds with bafflement. It's as though the Good person were seeking some sort of obscure advantage which the Evil person can't discern. In rejecting the Good person's action, the Evil person projects their own lack of trustworthiness. In the process, giving him or herself away.