Perfect lesson about the nature of perception is contained in the short story "A Fable," by famous American author Mark Twain An artist creates a beautiful picture and places it so that it is reflected in the mirror. The animals in the forest get to know about the picture from the cat. The animals ask what is a mirror, and the cat describes it as a hole in the wall. Someone looks in it, and there he sees the picture. The donkey doubts and the cat becomes offended. The animals let the donkey bring them the evidence that the picture isn't beautiful. The donkey goes and looks in the mirror, and comes back and tells what he found there. By mistake the donkey stays between the picture and the mirror. The result is that he sees nothing in that hole but an donkey. All animals go to look in the mirror. Of course they see only their reflections. The author sums up with a conclusion. Which one? Get acquainted with A Fable by Mark Twain to know it.