Once upon a time, there was a blind man who did not know what the Sun is. So he asks other people to explain.
One man said, "The Sun is shaped like a copper plate." So the blind man banged
on a copper plate, and listened to its clanging sound.
Later when he heard the sound of a temple bell, he thought that must be the Sun.
Another man said,"The Sun gives out light just like a candle." So the
blind man picked up a candle to feel its shape.
Later when he picked up a flute, he thought this must be the Sun.
And yet we know that the Sun is vastly different from a bell or a flute; but the blind man does not understand the differences, because he has never seen the Sun and only heard it described.
Su Shi, Song Dynasty
Complete Works of Su DongPo