One that desires to excel should endeavor in those things that are in themselves most excellent.
EpictetusThe soul's impurity consists in bad judgements, and purification consists in producing in it right judgements, and the pure soul is one which has right judgements, for this alone is proof against confusion and pollution in its functions.
EpictetusNothing outside the will can hinder or harm the will; it can only harm itself. If then we accept this, and, when things go amiss, are inclined to blame ourselves, remembering that judgment alone can disturb our peace and constancy, I swear to you by all the gods that we have made progress.
Epictetus