Shortly after he met Erasmus in Louvain in 1518, Juan Luis Vives wrote the Fabula de homine. Since it is one of the pivotal Humanist texts for the problems of form and theme that I shall be discussing in Calderón, I want to begin by recounting it. What I call the theatrical “idea” in connection with Calderón's La vida es sueño, as well as most of what I have to say about the importance of theatrical form in Calderón's development of the thematics of illusion, has immediate roots in the Humanist notion, exemplified in Vives' fable, that all the forms of human self-imagining bear directly and critically on the substance of that self-image. Theatre for Calderón, I shall be arguing, serves this function of self-imagination and critique.

At Juno's birthday feast, the goddess asked Jupiter, her brother and husband, to arrange some entertainment. At Jupiter's command, an amphitheatre appeared – stage and galleries. The divine spectators were seated in the uppermost gallery, in the skies; the earth was placed in the middle, as a platform for the actors. Jupiter was the director of the troupe; they knew tragedies, comedies, satires, farces, and mimes. Juno was greatly pleased. She walked among the gods and asked them which of the actors they considered the finest of the group. In the opinion of prominent critics, man was deemed worthy of highest praise.

Looking carefully at man, the gods who were seated near Jupiter could see some similarities between him and his master. In his wisdom, his prudence, his memory, in many of his talents, man seemed god-like.