Make a right judgement
Hua Tuo was a great medical scientist in China. He had excellent medical skills and always made a right judgement of the illness.
One day, two guys came to his home. Both of them said they had headache and fever. But, after diagnosing two of them, Hua Tuo gave them two kinds of different medicine. These two men were confused and asked: “We have the same symptom, why should we take different medicine?” Hua Tuo smiled: “Although your symptom looks the same, it was caused by different causes. So you should take different medicine.”
Soon after, these two men recovered.