1. Moral good and moral evil are primarily in the will. Human acts performed externally under command of the will, take their morality, first and foremost, from the will itself.
2. Yet there are some external acts which are evil in themselves because, by their very nature, they are out of line with right reason; the will cannot make these acts good. Such external acts are, for example, murders, injuries inflicted, impure conduct. The moral character of an external human act is not, therefore, wholly determined by the will of the person who performs the act.
3. When an external act takes its moral character from the will of the person who performs it, the goodness or evil of the act is one with the goodness or evil of the will. But when the act has intrinsic goodness or evil, there is a difference between the moral quality of the act and the moral quality of the will which commands it. True, these moralities coalesce, but they are not the same thing. A group of people praying vocally are all performing the same intrinsically good act. But each member of the group brings his own degree of devotion to the act of praying vocally. The external act is the same for all, but it is not equally good in all by that goodness which the act has from individual wills.
4. The external act adds something to the internal act of will. For the external act is the perfecting of the internal act. A man who intends to do a good deed, but fails to carry out the intention, has less good in his conduct than another who has the same good intention and fulfills it by performing the external good deed.
5. The consequences of an external act do not of themselves affect the goodness or evil of the act. Of course, such consequences as are foreseen, or should be foreseen because they follow naturally from the act, are part and parcel of the act itself, and are willed by the fact that the act is willed. But consequences unforeseen, and unconnected with the act by any natural or necessary bond, cannot work back upon the act and make it better or worse after it has been performed.
6. One and the same external act cannot be both morally good and morally evil. In the physical order an action may be good and also bad, as, for example, the taking of a medicine which is a relief for pain but harmful to the heart. In the moral order this cannot be. If a person steps out to commit a crime, and, on the way, decides not to commit it, we have one physical act of walking, but two acts of the will. The walking, as a human act, is morally bad up to the point of the person's change of intention; then it becomes another walking altogether, and is a morally good act. Here we have two acts, not one.
"The name of Jesus, pronounced with reverence and affection, has a kind of power to soften the heart. "
"A person who rails at God in adversity, suffers without merit; moreover by his lack of resignation he adds to his punishment in the next life and experiences greater disquietude of mind in this life."
St Alphonsus de Liguori
"God has no need of men."