Hume, the eminent Scottish philosopher and historian, was a close friend of Ramsay and both were founder members of The Select Society a distinguished debating club in Edinburgh. He supported Ramsay's rejection of idealism in painting in favour of a more truthful and natural representation celebrated in this portrait. Hume rests his left arm informally on two books possibly alluding to his own publications such as his 'Treatise on Human Nature' and 'The History of England' as well as to his knowledge. One of the volumes is by the Roman historian Tacitus. The portrait was painted as a companion to Ramsay's portrait of Rousseau which is also in the collection.