What the expression is intended to mean, I think, is that there is a better and a worse element in the character of each individual, and that when the naturally better element controls the worse then the man is said to be "master of himself", as a term of praise. But when - as a result of bad upbringing or bad company one s better element is overpowered by the numerical superiority of one s worse impulses, then one is criticized for not being master of oneself and for lack of self control.
PlatoWhat is at issue is the conversion of the mind from the twilight of error to the truth, that climb up into the real world which we shall call true philosophy.
PlatoRemember how in that communion only, beholding beauty with the eye of the mind, he will be enabled to bring forth, not images of beauty, but realities (for he has hold not of an image but of a reality), and bringing forth and nourishing true virtue to become the friend of God and be immortal, if mortal man may.
PlatoIf one sins against the laws of proportion and gives something too big to something too small to carry it - too big sails to too small a ship, too big meals to too small a body, too big powers to too small a soul - the result is bound to be a complete upset. In an outburst of hubris the overfed body will rush into sickness, while the jack-in-office will rush into the unrighteousness that hubris always breeds.
Plato