On Heroes, Hero-Worship, and the Heroic in History gathers six lectures Carlyle delivered in 1840. His subject is the great man: how such figures appear in the world, what work they do, and how other men receive them. He states the governing thesis early, that universal history is at bottom the history of the great men who have worked here, and that all standing achievements are the outer realization of thoughts that first lived in heroic souls.
The lectures move through six forms in which the hero has appeared, arranged roughly by historical era. The Hero as Divinity treats Odin and Scandinavian paganism, where loving wonder could still take a great man for a god. The Hero as Prophet treats Mahomet and Islam, the second phase, in which the great man is revered not as god but as one God-inspired.
The Hero as Poet turns to Dante and Shakespeare, figures Carlyle says belong to all ages and do not pass with changing knowledge. The Hero as Priest treats Luther and Knox, the priest being for him a kind of prophet who unites people with the unseen holy and enlightens daily life. The Hero as Man of Letters treats Johnson, Rousseau, and Burns, a wholly modern form in which a great soul rules nations from a garret through printed books.
The final lecture, the Hero as King, treats Cromwell and Napoleon. The king is the practical summary of all the other forms: the able-man whose will others rightly obey. Carlyle argues that the central business of all society is to find its ablest man and invest him with the room and authority to lead.
Running beneath the historical survey is a single moral argument. The hero in every shape is marked by sincerity, an unconscious grip on the reality of the universe, and the right response to him is hero-worship, the admiration of one higher than oneself. Carlyle ties loyalty, religion, and the whole order of society to this reverence, and reads the temper of each age in how it welcomes, or fails to welcome, its great men.