he knows to be seriously wrong, although there is no actual weighing of motives for doing or avoiding the act, no actual thought of God, no explicit calling to mind of the terrible consequences of mortal sin. Men who never think of God from morning till night, men who do not believe in hell, certainly commit mortal sins when they do what their consciences tell them is seriously wrong. Their conscience, as we saw above, is the voice of God.
(b) Besides advertence of the mind to the malice of the act, there must be full and free consent of the will to do it. If a man does not give full consent, but only dallies with the temptation, there is venial but not mortal sin; if, through being only half conscious or partially deranged, he has not full control over his will, he cannot be guilty of mortal sin.
After a temptation to sin is over, the conscience is sometimes uncertain and troubled as to whether full consent was given to sin. Often one may form one's conscience on the point by reflecting whether he was fully awake or conscious of what he was doing, whether the sinful act to which temptation impelled him was executed if there was the opportunity of doing so. If doubt remains, it should be settled by presumptions drawn from what usually happens. If he usually yields to such temptations, the presumption is that he did so on this doubtful occasion; the presumption is in his favour if he does not usually yield consent.
(c) The object or the matter to which consent is given must be seriously against the moral law in order that a sin may be mortal.
The matter is serious as a rule when the sin committed is directly against our duty to God, as blasphemy, heresy, hatred of God, idolatry, despair of God's mercy.
The matter is also serious when the sin causes great harm to our neighbour, as do sins against justice, charity, and obedience.
When sins cause great harm to the sinner himself the matter will also be serious and the sins mortal. This is the case with sins of intemperance and lust.
3. Some grievous sins are always mortal if there be full advertence and consent in the act. They do not admit parvity of matter, as theologians say. On the other hand, some sins, which if the matter be serious are mortal, become venial when the matter is light; sins against justice and charity are of this kind. It is a mortal sin to steal ten pounds, it is a venial sin to steal a penny. Some sins are of their nature venial, and
