He who defends the thesis of a twofold Morality merely shows that he does not possess simple Morality.
Theological thought is faced with a problem in ethics which presents the greatest difficulties. It is the problem of Free Will.
Is man who perceives, judges, has volition and acts, a free being inwardly? Can he, guided only by his own reasonable thoughts and conclusions, determined entirely by his own inner impulses and uninfluenced by outer circumstances, choose one or the other of two conflicting possibilities? When he has to make a decision, is he always like Hercules at the cross-roads who has to make up his mind alone as to which path he shall take, whether he is to follow quiet, modest virtue, or alluring, voluptuous vice? Does he do evil because he willed to do so and not otherwise, although it was in his power to avoid it? Does he decide for the good, because after due investigation and consideration he recognized it as preferable, though he might have rejected it? Or is man always subject to coercion from which at no time and no place he can escape? Are all his actions determined by the law of Nature which regulates every one of his movements just as mechanically as the course of the stars or the fall of a body to our earth when its support is removed? Is he an automaton, set going by cosmic forces, who possesses the doubtful privilege consciously to be able to follow the turning of his wheels, the action of his levers, rods and indicators and to listen to their humming and knocking without being allowed to interfere in their movements or to change the least thing in their functions or work? Is he fettered by the chain of causes which have existed eternally and continue to act immutably to all eternity?
Theological thought is condemned to find an answer to the question of freedom or determinism, as it is the necessary condition for the essential concepts of the theological doctrine of Morality, that is, the concept of responsibility and those consequent upon this, namely, sin, reward and punishment. For the true believer God is the source of Morality. He Himself is Morality. What He ordains is good in itself and cannot be otherwise, for there is no room for evil in His nature, since if He could be conceived to do evil, it would by the very fact of His doing it become good. A man, to be moral, must approximate to the nature of God as nearly as it is granted to mortals to do. The moral law is revealed by God's mercy to give man a light which shows him the right path and lights him on his way. Thanks to Him the poor mortal is relieved of the incertitude due to his limited mental powers and is endowed with the priceless possession of a certain precept which he need only obey in order to be sure of salvation.