Captains and the Kings Themes
One theme is the greed of those who have, as opposed to the ignorance and credulity of those who have not. The story is of Joseph Armagh's revenge on a world that forced him to deny his own identity as an Irishman and as a "Roman" (Catholic). By Joe's own characterization, mankind is the most selfish species ever "spewed out of hell," and the novel is consistent with this vision. Joe's ruthless climb to the top is a joyless quest devoid of humor, satisfaction, or empathy.
Because the inevitable assassination of his son Rory Armagh is accompanied by references to the apocalyptic vision of St. John the Divine who foretold the enslavement of the world, there is as well a lesson in the implacability of Biblical prophecy. The last true episode of the book is a scene with Sister Mary Bernarde in a Maryland convent. The room smells of wax and fern and incense, and the nun's aged voice is firm and gentle and consoling, even as she hears of her brother's death. Caldwell appears to be saying, then, that if the vision of St. John is inevitable through the workings of the captains and the kings who serve the cabal of the Elite, then perhaps the most admirable and effective tactic for survival is in monastic seclusion, away from the terror and the pitfalls of this bedeviled world.
A minor theme is the counterpoint that Caldwell develops between the two basic types of Irishmen: the blithe and outgoing Irishman as opposed to the morose and Druidical. Joe represents the latter type, while the cheerful breed is typified by Joe's father Daniel and by his brother Sean, both of whom Joe despises. He hates his light-hearted and irresponsible father because he failed to provide for his family in death, and he hates Sean because he so much resembles their father. The gifted and sensitive Sean, first a minstrel and then a famous tenor, assumes a further dimension of scorn in his brother's eyes: Having become homosexual, he is murdered by his jealous lover.