Rome in Shakespeare's Julius Caesar is a superstitious place.
Caesar demonstrates his superstitious beliefs when he arranges for Antony to touch the barren Calphurnia while he runs the race in Act 1, because superstition suggests that the touch may cure Caesar's wife of her inability to have children.
Caesar makes the mistake, however, of ignoring superstition when he fails to follow the Soothsayer's advice to beware the ides of March.
Furthermore, the chaotic state of human affairs in the play is reflected by bad omens. A slave's hand appears to be consumed by fire one minute, but not at all burned the next. A lion is loose in the city by the capitol. Caesar's ghost appears to Brutus on the eve of battle.
Superstition in the play reflects the state of Roman politics, highlights Caesar's refusal to accept advise and accept his fragility, and foreshadows events to come.