Niccolò Machiavelli
Discourses on the First Decade of Titus Livius (Chap. 1.45)
That it is of evil example, especially in the Maker of a Law, not to observe the Law when made: and that daily to renew acts of injustice in a City is most hurtful to the Governor.

Terms having been adjusted, and the old order of things restored in Rome, Virginius cited Appius to defend himself before the people; and on his appearing attended by many of the nobles, ordered him to be led to prison. Whereupon Appius began to cry out and appeal to the people. But Virginius told him that he was unworthy to be allowed that appeal which he had himself done away with, or to have that people whom he had wronged for his protectors. Appius rejoined, that the people should not set at nought that right of appeal which they themselves had insisted on with so much zeal. Nevertheless, he was dragged to prison, and before the day of trial slew himself. Now, though the wicked life of Appius merited every punishment, still it was impolitic to violate the laws, more particularly a law which had only just been passed; for nothing, I think, is of worse example in a republic, than to make a law and not to keep it; and most of all, when he who breaks is he that made it.

After the year 1494, the city of Florence reformed its government with the help of the Friar Girolamo Savonarola, whose writings declare his learning, his wisdom, and the excellence of his heart. Among other ordinances for the safety of the citizens, he caused a law to be passed, allowing an appeal to the people from the sentences pronounced by "the Eight" and by the "Signory" in trials for State offences; a law he had long contended for, and carried at last with great difficulty. It so happened that a very short time after it was passed, five citizens were condemned to death by the "Signory" for State offences, and that when they sought to appeal to the people they were not permitted to do so, and the law was violated. This, more than any other mischance, helped to lessen the credit of the Friar; since if his law of appeal was salutary, he should have caused it to be observed; if useless, he ought not to have promoted it. And his inconsistency was the more remarked, because in all the sermons which he preached after the law was broken, he never either blamed or excused the person who had broken it, as though unwilling to condemn, while unable to justify what suited his purposes. This, as betraying the ambitious and partial turn of his mind, took from his reputation and exposed him to much obloquy.

Another thing which greatly hurts a government is to keep alive bitter feelings in men's minds by often renewed attacks on individuals, as was done in Rome after the decemvirate was put an end to. For each of the decemvirs, and other citizens besides, were at different times accused and condemned, so that the greatest alarm was spread through the whole body of the nobles, who came to believe that these prosecutions would never cease until their entire order was exterminated. And this must have led to grave mischief had not Marcus Duilius the tribune provided against it, by an edict which forbade every one, for the period of a year, citing or accusing any Roman citizen, an ordinance which had the effect of reassuring the whole nobility. Here we see how hurtful it is for a prince or commonwealth to keep the minds of their subjects in constant alarm and suspense by continually renewed punishments and violence. And, in truth, no course can be more pernicious. For men who are in fear for their safety will seize on every opportunity for securing themselves against the dangers which surround them, and will grow at once more daring, and less scrupulous in resorting to new courses. For these reasons we should either altogether avoid inflicting injury, or should inflict every injury at a stroke, and then seek to reassure men's minds and suffer them to settle down and rest.