What metaphors are used in The Sleep of Reason by Antonio Buero Vallejo?

From one side The Sleep of Reason is a study in imperial repression. But more importantly, the work explores the effects of repression, threat, and intimidation on individuals, most importantly in this case, on Goya. The painter lives in fear of the political consequences of his affiliations, and as a direct or indirect result, exhibits a number of symptoms—from increased insecurity accompanying diminished sexuality, to auditory and visual hallucinations. Buero Vallejo's play can be seen as a metaphor for political and psychological history.