Usually classified as the most obvious archetype — although it belongs largely to the conscious — is the persona. This was the Roman actor’s word for the mask he wore to indicate his assumed character, and Jung uses it in much the same sense: the face which each individual presents to his surroundings. It involves a certain amount of necessary and healthy play acting, easing the relations between a man’s inner world and the world around him. The persona is injurious only when it dominates the true personality beneath.

One danger then is that the persona will blind a man to the existence of his own shadow. This shadow, part of the personal unconscious, is the Mr. Hyde in every Dr. Jekyll, the inferior or evil element that wants to do what the conscious or the conscience forbids. It is necessary to control the shadow, but there is danger: the more firmly it is stamped upon, the greater the force with which it will eventually erupt.

Time Magazine 1955 quote. Interview with Carl Jung.