Abu Mansur al-Baghdadi in Manaqib al-Shafi`i and Naqd Abi `Abd Allah al-Jurjani fi Tarjih Madhhab Abi Hanifa relates the following example of the Imam's perspicuity at an early age:
Al-Shafi`i was sitting at Malik's feet one day when a man came in and said: "I sell turtle-doves, and one of my customers returned one of them to me today, saying that it does not coo, so I swore to him on pain of divorce that my turtle-dove coos all the time!"
Malik said: "You have divorced your wife and are not to approach her."
Al-Shafi`i was fourteen at the time. He said to the man: "Which is more, your turtle-dove's cooing or its silence?" The man said: "Its cooing."
Al-Shafi`i said: "Consider your marriage valid, and there is no penalty on you." Where upon Malik frowned at him saying: "Boy! How do you know this?"
Al-Shafi`i replied: "Because you narrated to me from al-Zuhri, from Abu Salama ibn `Abd al-Rahman, from Umm Salama, that Fatima bint Qays said: 'O Messenger of Allah! Abu Jahm and Mu`awiya have both proposed to me.'
The Prophet replied: 'As for Mu`awiya he is penniless, and as for Abu Jahm he does not put down his staff from his shoulder [from travel].'1 Meaning: in most of his states; for the Arabs declare the more frequent of two actions [exclusively of the other] because of its constancy. And since the cooing of this man's turtledove is more than its silence, I declared it constant in its cooing." Malik was pleased at his reasoning.
1,Narrated by Bukhari and Muslim.
2In Ibn al-Subki, Tabaqat al-Shafi`iyya al-Kubra (5:147-148).