Discipline is the practice of acting in submission to a chosen purpose. Discipline is how well you execute what should be done in spite of how you feel about it.
Discipline comes from purpose, not feelings. When you transcend your feelings in service of your purpose, you become disciplined.
Feelings are fickle, and those governed by them are slaves to a master they can’t summon on demand. Your purpose, on the other hand, is always waiting for you whenever you choose to attend to it.
Discipline can overcome any feeling. You can’t always directly control how you feel right now, but you can always control what you think and do. When you are disciplined, you have complete control over your mind and your actions. You choose what you want to think and you do what you want to do.
Discipline is explicit and active. It requires intentional consideration of all options of action available and the selection and execution of the choice of the greatest long-term value.
Discipline detaches from the short-term. Discipline frequently requires you to act contrary to your short-term feelings.