not only against justice, but also against the fourth commandment or the virtue of piety. If a thief steals a consecrated chalice, the sacredness of the object makes the sin a sacrilegious theft, a circumstance indicated by what. And so of the rest.
It is obvious that circumstances of this kind are sources of morality, for they make the action conformable or not to the norm of morality. It is against right reason to strike anyone unjustly, but it is still more inordinate to strike a parent. At the proper time it is a good action to play in the proper place and with good playmates; if any of these circumstances be wanting, the action becomes so far bad.
2. Some circumstances affecting the intensity, or quantity, or duration of an action add to or lessen its malice, but they do not change its moral species; such circumstances are called aggravating circumstances. Although they do not change the moral species of the act, they sometimes make a venial sin mortal, or vice versa, as the quantity in theft; they are then said to change the theological species of the action. If the circumstances add to the action a special and distinct malice of their own, they change its moral species, as the sacred object or place in a sacrilegious theft. Such a theft is not only against justice, but also against the virtue of religion.
3. In order that an action may be altogether and simply good, the object, the end, and the circumstances must all be good; for good indicates completeness and perfection; there .is evil in any defect. If all the sources of morality are evil, the action may have a triple malice; as when a thief steals Church plate in order to be able to indulge his vicious propensities. If only one source or circumstance of an action be mortally sinful, the perpetration of it turns the evil-doer away from God and makes the action wholly bad. An accidental and secondary circumstance, when only venially sinful, does not corrupt the whole action; it only lessens its merit. Thus it is a grievous sacrilege to receive Holy Communion in a state of mortal sin; a state of venial sin only makes the Communion less fruitful.
SECTION III
On Merit
I. It follows from what has been said in the preceding section, that an action will be morally good if the object, end, and circumstances are good. The object, end, and circumstances will be good if they are conformable to man's rational