John Locke, James Augustus St. John (1872). “Philosophical Works: Preliminary discourse by the editor. On the conduct of the understanding. An essay concerning human understanding”, p.137
William Law (1749). “I. The spirit of prayer; or, the soul rising out of the vanity of time, into the riches of eternity. In two parts ; 7,II. The way to divine knowledge; being several dialogues between Humanus, Academicus, Rusticus, and Theophilus”, p.4