No one can see their own face directly without the mediation of a mirror, but the face reveals our identity, that which makes us unique to the eye. And since human beings have wanted to see the essence of people's physiognomy, while masks have been used either to hide it, or to protect against evil, establish new personalities or foster moods. Through history, fables and myths, this fascinating essay transports us to such emblematic places as Ancient Egypt or the Venice Carnival to discover the fascination with the mirror of the soul and its countless reflections.