The opposite of "corrupt"? Discipline, and self-discipline in particular I'd say.

Grades are more important, so they needed to be there. We talked during the week about self-discipline, that these boys are all smart enough to get good grades and play ball. It just takes work.

If a man will understand how intimately, yea, how inseparably, self-control and happiness are associated, he has but to look into his own heart, and upon the world around,...Looking upon the lives of men and women, he will perceive how the hasty word, the bitter retort, the act of deception, the blind prejudice and foolish resentment bring wretchedness and even ruin in their train.

Self discipline expresses itself in a variety of ways such as perseverance, the ability not to give up despite failure and setbacks, self control, the ability to resist distraction or temptation, & trying over again until you accomplish what you set out to do.

Self disciplined people keep their eyes on goal. If they encounter obstacles, instead of focusing on the obstacle, they find a way around it by keeping their goal in mind. It’s mindset of courage which makes easier to pursue success.

Self discipline is essence of life. Through self discipline you are able to inculcate good habits and willpower. It makes you to follow the best course of action or to rise to your commitments or principles. You have a strong sense of self-control in order to reach a desired goal. Developing these traits of good character can be difficult to foster and maintain, but they afford so many positive benefits to improve the quality of your life.