Why Tyrants cannot be Happy

For what person is there, in the name of gods and men! who would wish to be surrounded by unlimited wealth and to abound in every material blessing, on condition that he love no one and that no one love him? Such indeed is the life of tyrants - a life, I mean, in which there can be no faith, no affection, no trust in the continuance of goodwill; where every act arouses suspicion and anxiety and where friendship has no place. For can anyone love either the man whom he fears, or the man by whom he believes himself to be feared?
Marcus Tullius Cicero, Loeb De Amicitia Page 165

Amor misceri cum timore non potest! Love can not be mixed with fear! How true is it then that even if a tyrant was never brought to justice he has in the process of his crimes destroyed everything worthy of life, thus separating himself from any possibility of happiness. While being at war with the whole of mankind he is simultaneously at war with himself, bounding not only his victims but himself with the wretched fetters of despotism. So let no one say that it is ever in our interest to commit an injustice if we can avoid getting caught, as the punishment is not in getting caught but in the injustice itself, as you are removing by violence the very thing which can bring you happiness, virtue. As Epictetus said of a thief who had stolen his lamp, "He gained my lamp because he was superior to me in vigilance, he however paid this price, he consented to be a thief."