M. Tullius Cicero, De Officiis
Walter Miller, Ed.

[35] 8. Now when we meet with expediency in¹ some specious form or other, we cannot help being influenced by it. But if upon closer inspection one sees that there is some immorality connected with what presents the appearance of expediency, then one is not necessarily to sacrifice expediency but to recognize that there can be no expediency where there is immorality. But if there is nothing so repugnant to Nature as immorality (for Nature demands right and harmony and consistency and abhors their opposites), and if nothing is so thoroughly in accord with Nature as expediency, then surely expediency and immorality cannot coexist in one and the same object.

Again: if we are born for moral rectitude and if² that is either the only thing worth seeking, as Zeno thought, or at least to be esteemed as infinitely outweighing everything else, as Aristotle holds, then it necessarily follows that the morally right is either the sole good or the supreme good. Now, that which is good is certainly expedient; consequently, that which is morally right is also expedient.