James Burnett, Lord Monboddo (25 October 1714 – 26 May 1799) was a Scottish judge, scholar of linguistic evolution, philosopher and deist. He is most famous today as a founder of modern comparative historical linguistics. In 1767 he became a judge in the Court of Session. As such, Burnett adopted an honorary title based on his father's estate, Monboddo House. Monboddo was one of a number of scholars involved at the time in development of early concepts of evolution. Some credit him with anticipating in principle the idea of natural selection that was developed into a scientific theory by Charles Darwin.

James Burnett was born in 1714 at Monboddo House in Kincardineshire, Scotland. After his primary education at the parish school of Laurencekirk, he studied at Marischal College, Aberdeen from where he graduated in 1729. He also studied at University of Edinburgh and the University of Groningen. At Edinburgh University he graduated in law and was admitted to the Faculty of Advocates in 1737.

David Hume (7 May [O.S. 26 April] 1711 – 25 August 1776) was a Scottish philosopher, historian, economist, and essayist, known especially for his philosophical empiricism and scepticism. He was one of the most important figures in the history of Western philosophy and the Scottish Enlightenment. Hume is often grouped with John Locke, George Berkeley, and a handful of others as a British Empiricist.

Beginning with his A Treatise of Human Nature (1739), Hume strove to create a total naturalistic "science of man" that examined the psychological basis of human nature. In stark opposition to the rationalists who preceded him, most notably Descartes, he concluded that desire rather than reason governed human behaviour, saying: "Reason is, and ought only to be the slave of the passions." A prominent figure in the sceptical philosophical tradition and a strong empiricist, he argued against the existence of innate ideas, concluding instead that humans have knowledge only of things they directly experience. Thus he divides perceptions between strong and lively "impressions" or direct sensations and fainter "ideas", which are copied from impressions. He developed the position that mental behaviour is governed by "custom"; our use of induction, for example, is justified only by our idea of the "constant conjunction" of causes and effects. Without direct impressions of a metaphysical "self", he concluded that humans have no actual conception of the self, only of a bundle of sensations associated with the self.