Integrity is the first step to true greatness. Men love to praise, but are slow to practice it. To maintain it in high places costs self-denial; in all places it is liable to opposition, but its end is glorious, and the universe will yet do it homage.
Achievement of your happiness is the only moral purpose of your life, and that happiness, not pain or mindless self-indulgence, is the proof of your moral integrity, since it is the proof and the result of your loyalty to the achievement of your values.
but to begin with:
Honesty is the first chapter in the book of wisdom.