"He then communicated the various precepts given from time to time for the conquest of passion, and displayed the happiness of those who had obtained the important victory, after which man is no longer the slave of fear, nor the fool of hope; is no more emaciated by envy, inflamed by anger, emasculated by tenderness, or depressed by grief."
— Johnson, Samuel (1709-1784)
He enumerated many examples of heroes immovable by pain or pleasure, who looked with indifference on those modes or accidents to which the vulgar give the names of good and evil. He exhorted his hearers to lay aside their prejudices, and arm themselves against the shafts of malice or misfortune, by invulnerable patience; concluding, that this state only was happiness, and that this happiness was in every one's power.
See The Prince of Abissinia. A Tale. In Two Volumes. (London: Printed for R. and J. Dodsley; and W. Johnston, 1759). <Link to ESTC> <Link to Jack Lynch's online edition>
Reading The History of Rasselas, Prince of Abissinia, ed. Thomas Keymer (Oxford: OUP, 2009).