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.
PlatoHe who has knowledge of the just and the good and beautiful ... will not, when in earnest, write them in ink.
PlatoThe philosopher whose dealings are with divine order himself acquires the characteristics of order and divinity.
PlatoLove is the joy of the good, the wonder of the wise, the amazement of the gods; desired by those who have no part in him, and precious to those who have the better part in him.
PlatoFor the introduction of a new kind of music must be shunned as imperiling the whole state; since styles of music are never disturbed without affecting the most important political institutions.
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