a story that shows what a contradiction is comes from china. in this story, there is a merchant who sells both spears and shields. he says that his spears are so sharp that they could break through any shield. at the same time, he says that his shields are so strong that they could block any spear. this is a contradiction, because these two statements cannot both be true. either spear will break the shield or the shield will block the spear, but not both. for this reason, the word for contradiction in chinese is "máodùn" (矛盾), which literally means "spear and shield".