What does contradiction tell us?

This contradictory story tells us that whether we speak or do things, we should seek truth from facts, think twice before you act, and we should not exaggerate the facts too much. Contradiction is also a four-character idiom, which means that there is no logic before and after speaking or doing things. Its source is Han Feizi's Difficult. There can be no unbreakable shield and invincible spear in the world. The Chu people unilaterally exaggerated the role of spears and shields, resulting in a situation that could not be justified. Metaphor is inconsistent in speaking and doing things, and it is impossible to justify itself.

story

During the Warring States Period, there was a man in Chu who sold spears and shields. He first boasted that his shield was hard and said, "Nothing can destroy it!" " Then he boasted that his spear was sharp and said, "It can destroy everything! "The hostages in the market asked him," What will happen to them if you stab your shield with your spear? " The man couldn't answer. People laughed at him. A shield that cannot be pierced and a spear that can pierce all shields cannot coexist.