這個成語出自《韓非子·難一》。
古時候,矛和盾都是作戰(zhàn)用的武器。矛用來刺殺敵人,盾則用來保護身體,以免被對方的矛刺中。
傳說很久以前,楚國有個賣兵器的人,在市場上賣矛和盾。為了讓人家愿意買他的貨,他先舉起盾向人們夸口道:“你們看,我的盾是世上最堅固的盾,任何鋒利的東西都不能刺穿它。”接著又舉起他的矛,向人吹噓說:“你們再看看我的矛,它鋒利無比,無堅不摧,無論多么堅硬的盾,都擋不住它,一刺就穿!”
圍觀的人聽了他的話都覺得很好笑,人群中有人問道:“依你的說法,你的矛無論怎樣堅硬的盾都能刺穿,而你的盾又是無論多么鋒利的矛也不能把它刺穿。那就拿你的矛來刺你的盾吧,看看結果怎么樣?”
賣兵器的人聽了張口結舌,無從回答,只好拿著矛和盾走了。
“自相矛盾”就是由這個故事演變而來的?,F(xiàn)在人們用它來比喻做事、說話前后自相抵觸。
A man of the state of Chu had a spear and a shield for sale. He was loud in praises of his shield.
"My shield is so strong that nothing can pierce it through."
He also sang praises of his spear.
"My spear is so strong that it can pierce through anything."
"What would happen," he was asked, "if your spear is used to pierce your shield?"
It is impossible for an impenetrable shield to coexist with a spear that finds nothing impenetrable.