In Tokyo in the Meiji era there lived two prominent teachers of opposite characteristics. One, Unsho, an instructor in Shingon, kept Buddha’s precepts scrupulously. He never drank intoxicants, nor did he ever eat after eleven o’clock in the morning. The other teacher, Tanzan, a professor of philosophy at the Imperial University, never observed the precepts. When he felt like eating, he ate, and when he felt like sleeping in the daytime, he slept.
One day Unsho visited Tanzan, who was drinking wine at the time, not even a drop of which is supposed to touch the tongue of a Buddhist [monk].
“Hello, brother,” Tanzan greeted him. “Won’t you have a drink?”
“I never drink,” replied Unsho solemnly.
“One who does not drink is not even human,” said Tanzan.
“Do you mean to call me inhuman just because I do not indulge in intoxicating liquids?” exclaimed Unsho in anger. “Then if I am not human, what am I?”
“A Buddha,” answered Tanzan
From 101 Zen Stories
as printed in Zen Flesh, Zen Bones
Red Vase, Lemon Study Seamus Berkeley