contradict oneself一般指“自相矛盾”即自打嘴巴或理解成自取其辱、出尔反尔。

【例句】
Very well then, I contradict myself.
很好，那么我就是要自相矛盾。

What you said and what you did contradict each other.
你的所作所为和你说的话根本就是自相矛盾。