(a) sins of weakness, which are those that result from antecedent concupiscence or other passion that lessens without taking away the voluntariness of an act. Since the First Person of the Trinity is especially described by the attribute of almighty power, sins of this kind are sometimes called sins against the Father;
(b) sins of ignorance, which are those that result from antecedent and vincible ignorance. Since wisdom is especially attributed to the Second Person of the Trinity, sins of this kind are called sins against the Son;
(c) sins of malice, which are those that proceed entirely from a free will that is undisturbed by ignorance or passion. Since love is especially ascribed to the Third Person of the Trinity, sins of this class are sometimes called sins against the Holy Ghost. Example: One whose heart is so set on wealth that he decides to sacrifice the friendship of God for new acquisitions; one who sees clearly the offense to God a sin entails, and deliberately chooses it; one who is so jealous of a neighbor that he schemes to ruin him; one who sins habitually without fear or remorse.
251. Other things being equal, sins of malice are graver than sins of weakness and sins of ignorance, since the former are more voluntary, more enduring, and more dangerous. But just as sins of ignorance and sins of weakness may be mortal, as when their object is seriously wrong, so sins of malice may be venial, as when their object is not seriously wrong. A fully deliberate lie that works no great harm is venially sinful, whereas a murder committed by one who was intoxicated or moved by rage is a mortal sin, if there was sufficient reflection.
252. The external causes of sin are: (a) the devil or other evil spirits, who by acting on the imagination or other sensitive powers of the soul attempt to draw mankind to destruction; (b) the world, that is, the persons and things about us, which by their seductiveness, or by their principles and examples, tend to draw away from the practice of virtue.
253. Since free consent is implied in the concept of formal sin, none of the internal or external causes of sin just mentioned, the choice of the will alone excepted, can actually effect sin. Hence the distinction between temptation and sin. The rebellion of the passions, the suggestions of evil spirits, the seductions of the world, are temptations; if the will does not yield to them, there is no sin, but rather virtue and merit.
254. In the presence of temptation fully adverted to, it is not lawful to remain indifferent (neither consenting nor dissenting), since this without just cause exposes one to the danger (see 258 sqq.) of being overcome by sin.
255. Resistance to temptation is made by the act of the will which commands the other powers not to yield and withholds its own consent to the sin suggested. This resistance may be:
(a) implicit or explicit, according as the dissent is expressed in what contains it, or is expressed in itself. Examples: Contempt of a temptation or displeasure over its presence is implicit resistance, while the resolve never to yield to it is explicit resistance;
(b) internal or external, according as it remains in the will, or is also exercised by the other powers. Examples: Displeasure over an uncharitable thought is internal resistance, while the reading of a book to divert the mind from the thought is external resistance;