Integrity is not just honesty in the abstract. It is the alignment between what you say and what you do, especially when no one is keeping score, or when keeping your word becomes inconvenient. It asks: are you the same person in private that you present in public?
Commitment is not enthusiasm at the start. Enthusiasm is easy. Commitment is what remains after the enthusiasm fades, when the work is hard, when no one around you seems to notice, when following through requires something of you that you would rather not give.
Excellence is not a performance for others. It is a standard you hold yourself to because you believe it matters, not because someone is measuring you, but because you have decided that this is the kind of person you want to be.
Together, they form something more than a set of rules. They form character.