From Musonius Rufus on How To Live:
You will earn the respect of all if you begin by earning the respect of yourself. Don't expect to encourage good deeds in people conscious of your own misdeeds.
How can we condemn tyrants, when we are much worse - we have the same impulses as theirs, but lack the opportunity to indulge them.
Rulers don't live long after they become used to defending themselves before their subjects with 'it is my will' rather than 'it is my duty'. Towards the ruled, you should aim to be regarded with awe, not fear. Reverence accompanies one, bitterness the other.
. . .
With the exception of philosophy, there is no study that develops self-control. It teaches you to be above pleasure and greed - admire thrift and avoid extravagance - it trains you to have a sense of shame, and to control your tongue - it produces discipline, order, and courtesy - in general, appropriate action. When these qualities are present in an ordinary person, they impart dignity and self-command - if present in a king they make him more godlike and worthy of reverence.
Courage breeds the fearless, the intrepid, the bold - so how else would you acquire these characteristics other than by having a firm conviction that death and hardships are not evils? For these are the things that unbalance and frighten you - philosophy is the only teacher that they are not evils. If kings ought to possess courage (and they should more than anyone else) - they must study philosophy - since they cannot become courageous by any other means.
. . .
It is of the greatest importance for the good king to be:
* Faultless and perfect in word and action (if he is to be a 'living law' as he seemed to the ancients)
* Ensuring good government and harmony
* Suppressing lawlessness and dissension
* A true imitator of Zeus - like him, father of his people
How could anyone be this king if they were not endowed with a superior nature, given the best possible education, and are possessing all the virtues of humanity?"
There is a lot of emphasis here on the "king", and in particular the idea that a good king is a philosopher, and idea certainly as old as Plato - the ideal "philosopher-king" described in Plato's Republic. Still, much of it is applicable to any leadership position. If one would lead well, one must be wise. The love and study of wisdom is essential to good leadership.