199. The following rules assist us in recognizing specific distinctions of sins. (a) Those sins are specifically different which are opposed to virtues that are specifically distinct. Thus, infidelity and despair are different in species, because opposed to faith and hope, which are two distinct species of virtue. (b) Those sins are specifically different that are opposed to specifically different objects of one and the same virtue—that is, to functions of the virtue, or to laws concerning it that have intrinsically different motives. Thus, sins of murder, theft, and false testimony, though opposed to the same virtue of justice, are specifically distinct, since they contravene obligations of that virtue whose purposes are morally distinct. (c) Those sins are specifically different that are opposed in specifically different ways to the same object of the same virtue, one opposing that object by way of excess and the other by way of defect. Thus, miserliness and extravagance are specifically distinct sins, because one falls short of, while the other goes beyond, the golden mean that is found in liberality.
200. Sins are not specifically distinct: (a) when they are opposed to the same virtue in ways that are physically, but not morally, contrary. Thus, sins of omission and sins of commission are physically opposites, but they are not morally so, unless they offend against different moral objects in the ways explained in the preceding paragraph. Hence, to steal and to refuse to pay debts, to take and to keep what belongs to another, are not specifically different sins; whereas to violate two distinct precepts about the same virtue, one a command and the other a prohibition, is to commit two species of sin, one by omission, and the other by commission;
(b) when they are opposed to the same virtue with reference to commands that differ in their lawgivers, but not in their motives. Thus, God, the Church, and the State all forbid theft; but he who steals is not therefore guilty of three sins, for each lawgiver forbids theft from the same intrinsic motive, viz., because it is an injury.
201. One and the same act contains in itself many sins, when it has many malices specifically different. Thus, he who kills his parents violates two commandments relative to the virtue of justice; he who steals from a church is guilty of theft and of sacrilege.
202. Sins that are multiplied numerically within the same species are committed in three ways: (a) by purely internal acts, that is, acts that are completed within the powers of the soul and do not tend to execution in some external act (e.g., unbelief, envy, pride, delight in the thought of sin, etc.); (b) by internal acts that are not completed in the will, but tend to execution in some external act (e.g., the purpose or desire to injure another, to lie, etc.); (c) by external acts that are performed or neglected by the bodily faculties under command of the will (e.g., theft, quarrels, lies, omissions of duty, etc.).
203. Acts may be numerically one or many in two ways.
(a) Physically, there is one act when the agent moves or puts into action a power of the soul or body only once (e.g., to steal from a church). Physically, there are many acts when the agent exercises different operative faculties, or the same one different times (e.g., to put one’s hand many times into a money box in order to steal the entire contents).
(b) Morally, there is one act when a single physical act does not contain more than one species of morality, or when several physical acts are united as parts of one whole by reason of the intention of the agent, or the nature of the acts themselves. For example, the wish to steal is morally one act. The intention to steal, the decision to use certain means to accomplish this intention, the various attempts made, and finally the carrying out of the plan—all these form morally but one act, since the acts that follow are only the development of the original intention. Similarly, several curses hurled at another form morally one act, if all are uttered under the influence of the same passion of anger. Finally, acts of spying on another, of entering his house without permission, and of taking his property unlawfully, are morally one act, because the first acts are naturally the preparation for what follows.
204. Morally, there are several acts when a single physical act contains several species of malice (as when one steals from a church), or when there are several physical acts not united by any bond of common purpose or natural subordination (as when one steals on different occasions because an opportunity suddenly presented itself, or as when one misses Mass on different Sundays).
205. Objects of acts may also be numerically one or many in two ways.