Fa-yen, a Chinese Zen teacher, overheard four monks arguing about subjectivity and objectivity. He joined them and said: "There is a big stone. Do you consider it to be inside or outside your mind?"
One of the monks replied: "From the Buddhist viewpoint everything is an objectification of mind, so I would say that the stone is inside my mind."
"Your head must feel very heavy," observed Fa-yen, "if you are carrying around a stone like that in your mind."