在很久以前的战国时期，有一个楚国人。
他是个卖盾和矛的人。
有一天，他先拿起他的盾说：“我这盾可坚固了，没有任何东西能穿透它。”
接着他又拿起他的矛说：“我这矛可锋利了，没有什么东西是它刺不穿的。”
旁边的人听到了，就问他说：“那如果你用你的矛去刺你的盾，会发生什么呢？”
这个问题让这个楚国人一下子不知道该怎么回答。
从那以后，人们就把这个故事叫做“自相矛盾”。
这个成语就是用来形容说话或者做事前后不一致，相互冲突的情况。
Long ago, during the Warring States period, there was a man from Chu.
He was a seller of shields and spears.
One day, he first picked up his shield and said, "My shield is very sturdy, nothing can penetrate it."
Then he picked up his spear again and said, "My spear is very sharp, there is nothing it cannot pierce through."
The people next to him heard this and asked him, "What would happen if you use your spear to stab your shield?"
This question left the man from Chu speechless.
From then on, people called this story 'Inconsistent'.
This idiom is used to describe a situation where words or actions are inconsistent and conflicting.
