Conditions that need to be fulfilled to determine the morality of human conduct. In order to judge the goodness or badness of any particular human act, three elements must be weighed from which every act derives its morality. They are: the object of the act, the circumstances surrounding the act, and the purpose that the one performing the act has in mind.
The object of a human act is that which the one acting sets out to do, as distinguished from his or her ultimate purpose in doing it. It is that which the action of its very nature tends to produce. For example, the object of a suicide's act is to take his or her life; the purpose may be to escape evils that person is unwilling to bear.
Moreover, the object is not merely the act considered in its physical makeup. It is the act viewed in its moral nature, i.e., the act considered in its relationship to the moral law. It answers to the question: Does it conform or is it contrary to the standard of right conduct? The circumstances of a human act are accidental modifications that affect its morality. Circumstances are capable of changing: an ordinary indifferent act into a sinful one, such as unnecessary servile work on Sunday; an ordinarily venially sinful act into a mortal sin, such as taking even a small amount of urgently needed money from a very poor man; an ordinarily mortally sinful act into a venial sin, such as blaspheming when only half aware of what one is doing; and a sinful action into a doubly sinful, such as unjustly striking a person consecrated to God.
The end or purpose of a human act is the intention that prompts one to perform such an act, as when a person reveals some hidden failing of another in order to injure that person's reputation.
A human action is morally good only if all three elements, namely object, circumstances, and purpose, are substantially good. An action becomes morally bad if even one of these three elements is bad. The reason is that we are always obliged to avoid all evil as far as we can. If an essential part of an action is evil, we cannot avoid that evil part unless we refrain from the whole action. If, then, one does an action in spite of the substantially evil element in it, one is performing a sinful action.