Miscommunication, both in the form of deception and self-deception, is endemic in the action of Shakespeare's Julius Caesar. This article investigates why this should be, and links the functions of miscommunication in the play with its psychoanalytic meanings as these have been outlined in particular by Bion. The truth is avoided or manipulated by most of the protagonists of the play as a response to their anxieties about catastrophic change. The fear of the conspirators that Caesar is about to accept a crown is only the focal point of a deeper anxiety about the threat to the Roman republic. The play is shown to illuminate unconscious forces involved in political leadership and mass politics in particular. The preparation and enactment of the assassination add a burden of failed mourning and of unassimilable guilt to already deep anxieties, all of which lead to the cumulative tragedies which the play depicts.