Blind Man and the Sun

Once upon a time, there was a blind man who does 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 hold a candle to feel its shape.
Later when he picked up a flute, he thought that this must be the Sun.

Yet we know that he Sun is vastly different from a bell or a flute; but a blind man does not understand the differences, because he has never seen the Sun and only heard it described.

Just like that matters introduced by others and seen and felt by oneself is different.