They do, but only when that measure is recommended by the public advantage: tyrants enjoy cruelty.
A tyrant differs from a king in deeds, not in title: for the elder Dionysius deserves to be preferred before many kings, and what can prevent our styling Lucius Sulla a tyrant, since he only left off slaying because he had no more enemies to slay?
Although he laid down his dictatorship and resumed the garb of a private citizen, yet what tyrant ever drank human blood as greedily as he, who ordered seven thousand Roman citizens to be butchered, and who, on hearing the shrieks of so many thousands being put to the sword as he sat in the temple of Bellona, said to the terror-stricken Senate, “Let us attend to our business, Conscript Fathers; it is only a few disturbers of the public peace who are being put to death by my orders.”
In saying this he did not lie: they really seemed few to Sulla.
But we shall speak of Sulla presently, when we consider how we ought to feel anger against our enemies, at any rate when our own countrymen, members of the same community as ourselves, have been torn away from it and assumed the name of enemies: in the meanwhile, as I was saying, clemency is what makes the great distinction between kings and tyrants.
Though each of them may be equally fenced around by armed soldiers, nevertheless the one uses his troops to safeguard the peace of his kingdom, the other uses them to quell great hatred by great terror: and yet he does not look with any confidence upon those to whose hands he entrusts himself.
He is driven in opposite directions by conflicting passions: for since he is hated because he is feared, he wishes to be feared because he is hated: and he acts up to the spirit of that odious verse, which has cast so many headlong from their thrones—
“Why, let them hate me, if they fear me too!”—
not knowing how frantic men become when their hatred becomes excessive: for a moderate amount of fear restrains men, but a constant and keen apprehension of the worst tortures rouses up even the most grovelling spirits to deeds of reckless courage, and causes them to hesitate at nothing.
Just so a string stuck full of feathers  will prevent wild beasts escaping: but should a horseman begin to shoot at them from another quarter, they will attempt to escape over the very thing that scared them, and will trample the cause of their alarm underfoot.
No courage is so great as that which is born of utter desperation. In order to keep people down by terror, you must grant them a certain amount of security, and let them see that they have far more to hope for than to fear: for otherwise, if a man is in equal peril whether he sits still or takes action, he will feel actual pleasure in risking his life, and will fling it away as lightly as though it were not his own.