It’s nice when a writer does not contradict herself. It is very kind indeed: If she does, then there are two choices: One, the task is up to the reader: given her presentation of both sides, which one comes out on top? Rarely will there be a case where both sides are given equal treatment. Two, give up and say you’ve contradicted yourself — this is bad writing. The best readers know when to choose. I tend to prefer the first. It’s more work but it can produce exciting interpretations.