In old Tokyo, two teachers named Unsho and Tanzan had opposing lifestyles. Unsho, a Shingon instructor, strictly followed Buddha’s precepts, abstaining even from food at night. Tanzan, a university professor, freely indulged in wine and sleep whenever he wished.
One day, abstinent Unsho visited Tanzan, who was drinking wine against Buddha’s precepts. “Have a drink!” said Tanzan. “I never drink!” replied Unsho.
“One who doesn’t drink is not human,” stated Tanzan. “Then if I’m not human, what am I?” challenged Unsho. “A Buddha,” answered Tanzan.