Wisdom from the (distant) past

[Socrates:] And amid evils such as these will not he who is ill-governed in his own person–the tyrannical man, I mean–whom you just now decided to be the most miserable of all–will not he be yet more miserable when, instead of leading a private life, he is constrained by fortune to be a public tyrant? He has to be master of others when he is not master of himself: he is like a diseased or paralytic man who is compelled to pass his life, not in retirement, but fighting and combating with other men.

Yes, he [Glaucon] said, the similitude is most exact.

Is not his case utterly miserable? and does not the actual tyrant lead a worse life than he whose life you determined to be the worst?

Certainly.

He who is the real tyrant, whatever men may think, is the real slave, and is obliged to practise the greatest adulation and servility, and to be the flatterer of the vilest of mankind. He has desires which he is utterly unable to satisfy, and has more wants than any one, and is truly poor, if you know how to inspect the whole soul of him: all his life long he is beset with fear and is full of convulsions, and distractions, even as the State which he resembles: and surely the resemblance holds?

Very true, he said.

Moreover, as we were saying before, he grows worse from having power: he becomes and is of necessity more jealous, more faithless, more unjust, more friendless, more impious, than he was at first; he is the purveyor and cherisher of every sort of vice, and the consequence is that he is supremely miserable, and that he makes everybody else as miserable as himself.

No man of any sense will dispute your words.

–Plato, Republic.