Leone strained to explain the title

Director Leone strained to explain the theme: "We all have some bad in us, some ugliness, some good. And there are people who appear to be ugly, but when we get to know them better, we realize that they are more worthy."

One reviewer took this and claimed that each of the three protagonists embody the three parts of human nature with Tuco representing the id (i.e. the "flesh") and Blondie representing the ego (i.e. the mind with its power of volition). Okay, that fits. But then he tried to argue that Angel Eyes (Van Cleef) represents the superego, which goes to show that he didn't understand this structural model of the psyche seeing as how the superego is the idealistic, heroic side of human nature (aka the "spirit") and Angel Eyes in the movie is anything BUT.