13. Let this, then, be our rule, Cic. de Off. III. 4, § 19. so that we may never go wrong between two things, one virtuous, the other useful. The upright man must never think of depriving another of anything, nor must he ever wish to increase his own advantage to the disadvantage of another. This rule the Apostle gives thee, saying: “All things are lawful, but all things are not expedient; all things are lawful, but all things edify not. Let no man seek his own, but each one another’s.” 1 Cor. x. 23, 24. That is: Let no man seek his own advantage, but another’s; let no man seek his own honour, but another’s. Wherefore he says in another place: “Let each esteem other better than themselves, looking not each one to his own things, but to the things of others.” Phil. ii. 3, 4.