I mean, crazy people don't think they're crazy so the fact that I don't think I'm crazy doesn't mean I'm not crazy.

疯子们都认为自己是正常的,所以我觉得自己不是疯子,并不能说明我就不是疯子

耶鲁公开课 - 心理学导论课程节选

And Descartes said, "How do I know I'm not crazy?

笛卡尔问道,"我如何才能确定我不是个疯子

耶鲁公开课 - 心理学导论课程节选