He was educated at the Edinburgh University, where he studied philosophy under Sir William Hamilton, and acquired the habit of applying notions derived from eclectic psychology to the analysis of aesthetic effects in poetry, rhetoric, and the fine arts.
His first publication in which he proved his mastery of this line of investigation was entitled Poetics, an Essay on Poetry, a work which he produced in 1852, while he resided in London.
Dallas also contributed to the Daily News, the Saturday Review (London), the Pall Mall Gazette, and the World.
[1] In 1866 he produced two volumes of a projected four-volume work named The Gay Science, a title borrowed from Provençal troubadours.
More recently he was engaged on a new edition of François de La Rochefoucauld's Maxims, and he wrote an elaborate article on that work, which was unpublished at the time of his death.