The theory is primarily attributed to the Scottish essayist, historian, and philosopher Thomas Carlyle, who gave a series of lectures on heroism in 1840, later published as On Heroes, Hero-Worship, & the Heroic in History, in which he states:
The great man theory is an approach to the study of history popularised in the 19th century according to which history can be largely explained by the impact of great men, or heroes: highly influential and unique individuals who, due to their natural attributes, such as superior intellect, heroic courage, extraordinary leadership abilities, or divine inspiration, have a decisive historical effect. Napoleon, a typical great man, said to have created the 'Napoleonic' era through his military and political genius. Consider transferring direct quotations to Wikiquote or, for entire works, to Wikisource. Please help improve the article by presenting facts as a neutrally worded summary with appropriate citations. This article contains too many or overly lengthy quotations for an encyclopedic entry.