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.
PlatoPeople are like dirt. They can either nourish you and help you grow as a person or they can stunt your growth and make you wilt and die.
PlatoThere should exist among the citizens neither extreme poverty nor again excessive wealth, for both are productive of great evil.
PlatoTo conquer oneself is the best and noblest victory; to be vanquished by one's own nature is the worst and most ignoble defeat.
Plato