by St. Augustine
The precept: Thou shalt not kill: is of the righteousness of the Pharisees; the counsel: Thou shalt not be angry with thy brother without a cause: is of the righteousness of them which shall enter into the kingdom of heaven. The least therefore is: Thou shalt not kill, and whosoever shall break this commandment, he shall be called the least in the kingdom of heaven. But whosoever shall do it, and not kill, he is not therefore great, and meet for the kingdom of heaven; nevertheless, he hath risen a step; but he will have gotten farther, if he be not angry with his brother without a cause, the which, if he do, he will be the farther off from manslaughter. Wherefore, he that teacheth us that we are not to be angry without a cause, destroyeth not the law, Thou shalt not kill, but rather fulfilleth and increaseth it, making us not only to be free of the sin of outward killing, but also clean of anger within.
In sins of this kind there are divers steps. The first is this, that when the swelling emotion of anger appeareth in a man's heart, he keepeth it. Next, the inward disturbance wringeth forth words of indignation, not themselves meaning aught, but shewing the vexation of him who is provoked. And this is something worse than anger kept covered under silence. Next, this audible outburst of indignation may contain direct and open reviling of him who hath roused it. And it cannot be doubted that this is something worse than an empty cry of anger.
Behold here the three degrees of guilt open respectively to the judgment, to the council, and to hell-fire. As long as it is a matter of the judgment, there is still place for defence. In the council, albeit this also is in a sense a judgment, the sentence is pronounced, (so we may suppose,) not as the result of a trial whereat the accused is present, but as the result of a consultation among the judges, as to what punishment he is to receive because of his already established guilt. When we get to hell-fire, there remaineth no longer any doubt about condemnation as in the judgment, and no longer any doubt about sentence, as in the council. In hell-fire, the condemnation and the pain of him that is condemned are alike certain.