I wish to prove the truth of this by an example drawn from your own family.
The late Emperor Augustus was a mild prince, if in estimating his character one reckons from the era of his reign; yet he appealed to arms while the state was shared among the triumvirate.
When he was just of your age, at the end of his twenty-second year, he had already hidden daggers under the clothes of his friends, he had already conspired to assassinate Marcus Antonius, the consul, he had already taken part in the proscription.
But when he had passed his sixtieth  year, and was staying in Gaul, intelligence was brought to him that Lucius Cinna, a dull man, was plotting against him: the plot was betrayed by one of the conspirators, who told him where, when, and in what manner Cinna meant to attack him.
Augustus determined to consult his own safety against this man, and ordered a council of his own friends to be summoned.
He passed a disturbed night, reflecting that he would be obliged to condemn to death a youth of noble birth, who was guilty of no crime save this one, and who was the grandson of Gnaeus Pompeius.
He, who had sat at dinner and heard M. Antonius  read aloud his edict for the proscription, could not now bear to put one single man to death.
With groans he kept at intervals making various inconsistent exclamations:—“What! shall I allow my assassin to walk about at his ease while I am racked by fears?
Shall the man not be punished who has plotted not merely to slay but actually to sacrifice at the altar” (for the conspirators intended to attack him when he was sacrificing), “now when there is peace by land and sea, that life which so many civil wars have sought in vain, which has passed unharmed through so many battles of fleets and armies?”
Then, after an interval of silence, he would say to himself in a far louder, angrier tone than he had used to Cinna, “Why do you live, if it be to so many men’s advantage that you should die? Is there no end to these executions? to this bloodshed?
I am a figure set up for nobly-born youths to sharpen their swords on.
Is life worth having, if so many must perish to prevent my losing it?”
At last his wife Livia interrupted him, saying: “Will you take a woman’s advice?
Do as the physicians do, who, when the usual remedies fail, try their opposites.
Hitherto you have gained nothing by harsh measures: Salvidienus has been followed by Lepidus, Lepidus by Muraena, Muraena by Caepio, and Caepio by Egnatius, not to mention others of whom one feels ashamed of their having dared to attempt so great a deed.
Now try what effect clemency will have: pardon Lucius Cinna.
He has been detected, he cannot now do you any harm, and he can do your reputation much good.”
Delighted at finding someone to support his own view of the case, he thanked his wife, straightaway ordered his friends, whose counsel he had asked for, to be told that he did not require their advice, and summoned Cinna alone.
After ordering a second seat to be placed for Cinna, he sent everyone else out of the room, and said:—“The first request which I have to make of you is, that you will not interrupt me while I am speaking to you: that you will not cry out in the middle of my address to you: you shall be allowed time to speak freely in answer to me.
Cinna, when I found you in the enemy’s camp, you who had not become but were actually born my enemy, I saved your life, and restored to you the whole of your father’s estate.
You are now so prosperous and so rich, that many of the victorious party envy you, the vanquished one: when you were a candidate for the priesthood I passed over many others whose parents had served with me in the wars, and gave it to you: and now, after I have deserved so well of you, you have made up your mind to kill me.”
When at this word the man exclaimed that he was far from being so insane, Augustus replied, “You do not keep your promise, Cinna; it was agreed upon between us that you should not interrupt me. I repeat, you are preparing to kill me.”
He then proceeded to tell him of the place, the names of his accomplices, the day, the way in which they had arranged to do the deed, and which of them was to give the fatal stab.
When he saw Cinna’s eyes fixed upon the ground, and that he was silent, no longer because of the agreement, but from consciousness of his guilt, he said, “What is your intention in doing this? is it that you yourself may be emperor?
The Roman people must indeed be in a bad way if nothing but my life prevents your ruling over them.
You cannot even maintain the dignity of your own house: you have recently been defeated in a legal encounter by the superior influence of a freedman: and so you can find no easier task than to call your friends to rally round you against Ceesar.
Come, now, if you think that I alone stand in the way of your ambition; will Paulus and Fabius Maximus, will the Cossi and the Servilii and all that band of nobles, whose names are no empty pretence, but whose ancestry really renders them illustrious—will they endure that you should rule over them?”
Not to fill up the greater part of this book by repeating the whole of his speech—for he is known to have spoken for more than two hours, lengthening out this punishment, which was the only one which he intended to inflict—he said at last: “Cinna, I grant you your life for the second time: when I gave it you before you were an open enemy, you are now a secret plotter and parricide.
From this day forth let us be friends: let us try which of us is the more sincere, I in giving you your life, or you in owing your life to me.”
After this he of his own accord bestowed the consulship upon him, complaining of his not venturing to offer himself as a candidate for that office, and found him ever afterwards his most grateful and loyal adherent.
Cinna made the emperor his sole heir, and no one ever again formed any plot against him.