Intellect (Right Reason) + Free Will (Choice)= Morality in ACT-ion
Intellect and free will are "powers" of the soul in the Aristotelian/Thomistic sense. Each one must be properly utilized for a person to perform a morally licit act.
If right-reason is followed by a proper (totally free) choice the resultant moral act will be praiseworthy. If not it will be shameful.
Choices which are not truly free that is, made by an agent exercising totally free will are not human in the fullest sense of the term. Human choices can not be compelled by external force.
Right-reason demands that authentic human dignity be served while giving glory to God who created man in HIS image. Joy* results from the human person acting with free will on the basis of right reason; ergo, it must be compatible with the will of God--to love God completely and your neighbor as yourself. The treatment of "self" in reference here must of course be in-keeping with the will of God since man is created in the Imago Dei (image of God). It is not God's will for a human being to act against his/her nature.
To treat one's neighbor fairly cannot mean to endorse virtually anything they elect to do. Each person has a warrant that is the freedom/responsibility to do (choose) good not evil. There is no freedom in the moral sense to choose or do evil since it is incompatible with the elevated nature of the human person. We have no "right" to engage in evil since any right we possess is grounded in our anthropology as derivative beings created in the image of God (being personified) and God is all good. Given the nature of that reality, it is impossible that one would have a right to do evil. One is physically free to do so but not morally justified in doing so.
All choices of any consequence which we can make as human beings of necessity involve good and evil--right and wrong. Those which do not are of no real import in the human sense. Man must recognize the truth about his nature--which is that of a derivative created being--in order to find peace and joy. Nothing but misery follows the man who believes he is either the result of a cosmic accident or completely self-sufficient!
*As contrasted with pleasure or temporary happiness which are "lower" (visceral) in a manner of speaking and of the body portion of the body/soul composite that makes up the human person. Joy in comparison is spiritual (of the soul) and higher.
--Dr. J. P. Hubert
