But the law of charity, founded in nature, makes my life more precious to me than his, for charity begins at home.  Then, to save his life, I must give mine; and he risks his to take mine!  I do not desire to kill my unjust aggressor, but I do intend, as I have a perfect right, to protect my own life.  If he, without cause, places his existence as an obstacle to my enjoyment of life, then I shall remove that obstacle, and to do it, I shall kill.  Again, a desperate remedy, but the situation is most terribly desperate.  Being given law of my being, I can not help the inevitable result of conditions of which I am nowise responsible.  The man who attacks my life places his own beyond the possibility of my saving it.

This, of course, supposes a man using the full measure of his rights.  But is he bound to do this, morally?  Not if his charity for another be greater than that which he bears towards himself, if he go beyond the divine injunction to love his neighbor as himself and love him better than himself; if he feel that he is better prepared to meet his God than the other, if he have no one dependent on him for maintenance and support.  Even did he happen to be in the state of mortal sin, there is every reason to believe that such charity as will sacrifice life for another, greater than which no man has, would wash away that sin and open the way of mercy; while great indeed must be the necessity of the dependent ones to require absolutely the death of another.

The aggression that justifies killing must be unjust.  This would not be the case of a criminal being brought to justice or resisting arrest.  Justice cannot conflict with itself and can do nothing unjust in carrying out its own mandates.  The culprit therefore has no grounds to stand upon for his defense.

Neither is killing justifiable, if wounding or mutilation would effect the purpose.  But here the code of morals allows much latitude on account of the difficulty of judging to a nicety the intentions of the aggressor, that is, whether he means to kill or not; and of so directing the protecting blow as to inflict just enough, and no more disability than the occasion requires.

Virtue in woman is rightly considered a boon greater than life; and for that matter, so is the state of God’s friendship in the soul of any creature.  Then, here too applies the principle of self-defense.  If I may kill to save my life, 1 may for a better reason kill to save my soul and to avoid mortal offense.  True, the loss of bodily integrity does not necessarily imply a staining of the soul; but human nature is such as to make the one an almost fatal consequence of the other.  The person therefore who kills to escape unjust contamination acts within his or her rights and before God is justified in the doing.

We would venture to say the same thing of a man who resorts to this extreme in order to protect his rightly gotten goods, on these two conditions, however:  that there be some kind of proportion between the loss and the remedy he employs to protect himself against it; and that he have well grounded hope that the remedy will be effective, that it will prevent said loss, and not transform itself into revenge.