To show the ultimate reasons for all moral duty, the question is also transposed to truth or falsehoods and to practical decisions on the meaning of right and not just and unjust.
Moral norms can be grasped outside the scope of decisions and practice.
Recognizing their meaning, the theoretical truth of good becomes manifested; it is superior to the category of the right which is essential for any ethical norm, while the obligatory form taken in the right duty is subordinated.
For St. Thomas Aquinas, the judgment of conscience transfers the principle of being good and acting well into the inner acceptance and approval of the truth about good (or evil); the original decisions and determinations of the will do make the norm to realize the norm.
Ethics intends to know the value of behaviors and justify the norms in accordance with the moral principles of being good as a man and because of acting well, which is not in the practical order for man, but normative in natural law.