If you will discipline yourself to make your mind self-sufficient you will thereby be least vulnerable to injury from the outside. – Critias of Athens

No man or woman has achieved an effective personality who is not self-disciplined. Such discipline must not be an end in itself, but must be directed to the development of resolute Christian character. – John S. Bonnell

No padlocks, bolts, or bars can secure a maiden better than her own reserve. – Miguel de Cervantes

He who lives without discipline dies without honor. – Proverb