Summa summae S. Thomae, Tomus III

In man there are two things, namely a spiritual nature and a bodily nature¹. To that extent does man love himself or his neighbor, inasmuch as he loves himself or his neighbor according to his spiritual nature.

I say 1°: Man ought to love himself more out of charity than his neighbor².

It is proved 1° from that passage, Matt., XXII, 39: You shall love your neighbor as yourself. From this it seems that man's love for himself is the exemplar of the love which is for another³.

But the exemplar is prior to what is exemplified. Hence Augustine, book I de Civit., c. 20: « He who loves received, he says, from himself the rule of loving his neighbor. » Therefore.

It is proved 2°. God is loved as the principle of the good on which the love of charity is founded⁴; but man loves himself as a participator of that good, and his neighbor as an associate in this good. Now participation is more excellent than association, just as unity is more excellent than union. Therefore man ought out of charity to love himself more than his neighbor.

I say 2°: Man ought to love his neighbor more than his own body; because that thing is more to be loved out of charity which has the fuller account of being lovable out of charity. Now association in the full participation of beatitude, which is the account of loving one's neighbor with respect to his soul, is a greater account of loving than participation in beatitude by way of overflowing, which is the account of loving one's own body. Therefore.

Yet, because the precept of loving one's neighbor, taking the proper body for his spiritual salvation, is affirmative, and although it always binds, nevertheless it does not bind at every moment, but in certain cases of necessity. A threefold necessity is distinguished: extreme, grave, and common. It is called extreme when the neighbor will perish for eternity unless he is helped; as if an infant were about to die without baptism. Grave, when without help he can be saved absolutely, but with great difficulty; as if someone near death and in mortal sin should ask for confession, without which he can be saved absolutely by contrition alone, but far more difficultly than by the sacrament. Common is the necessity in which sinners commonly find themselves, who run into common occasions of sinning.

According to this threefold necessity,

I say 3°: In extreme necessity, anyone is bound to expose his own life for the eternal salvation of his neighbor, if there is hope that he can be helped. In grave necessity, only those are bound upon whom the care of souls rests by office. In common necessity, no one is bound.

Proof. first part. 1° According to Scripture, 1 John, III, 16, we ought to lay down our lives for our brethren; which is true at least in extreme necessity. Hence Augustine, in the book de Mendacio, c. 6, n. 9, says: « A Christian will plainly not hesitate to lose his temporal life for the eternal life of his neighbor. »

2° We are bound to expose goods of fortune for saving the bodily life of a neighbor placed in extreme necessity, according to that passage, 1 John, III, 17: Whoever shall have the substance of this world, and shall see his brother in need, and shall shut up his bowels from him: how does the charity of God abide in him? Therefore, to save his spiritual life we ought to expose our bodily life. — The consequence is plain; because our bodily life stands related to the spiritual life of our neighbor as our riches do to his bodily life.

Take note, however, that those are not reckoned to be in extreme necessity who thrust themselves into danger of damnation through their own malice, such as those who enter into an unjust war, take up a duel, and the like, who can withdraw themselves from the danger by their own means.

Proof. second part. Those are more bound to provide for their flock, upon whom the care of souls rests by office, than those upon whom this care does not rest. Now these are bound in extreme necessity, while neither is bound in common necessity. Therefore those are bound in grave necessity upon whom the care of souls rests by office, and not others.

Besides, it would be hard to oblige a private person, who has undertaken no care of another beyond that general one which God has enjoined on everyone concerning his neighbor, to pour out his life for his salvation outside extreme necessity. Otherwise would it be, if the question concerned some loss in goods of fortune; for a private person ought to endure that for the salvation of his neighbor.

From this you will infer that pastors are bound, at the peril of their life, say in time of plague, to administer the sacrament of penance to their parishioners; because, although they could be saved absolutely with contrition, it is nevertheless difficult, and indeed far easier with attrition and the sacrament: hence they are in necessity, if not extreme, at least grave. As to the administration of the sacraments of the Eucharist and Extreme Unction, see what we wrote in the treatise on the Eucharist, dissert. VII, a. 4, You will ask 1° and in the treatise on Extreme Unction art. 7, You will ask 2°.

The third part is manifest; because common necessity, from which each person cannot so difficultly extricate himself, and better than anyone else, is not so great that we are bound to pour out our life for it.

[Nevertheless in common or ordinary necessity of either order, namely bodily and spiritual, one must succor one's neighbor even at slight inconvenience. 1° One must succor him, because love of neighbor demands this, and besides, if everyone omitted this duty, common necessity would become grave or even extreme. 2° At slight inconvenience only, because ordinarily the neighbor easily extricates himself from such a necessity, and if he is forced to endure it for a short time, it is not too burdensome for him.

Nor are you bound to come to the aid of everyone placed in common necessity; because others are held by the same obligation, and no one could fulfill it alone.

You will ask whether a man may expose his own bodily life for the bodily life of his neighbor.

Before I answer, I suppose 1° that it is lawful, indeed sometimes necessary, to expose temporal goods for the bodily salvation of one's neighbor; for the life of one's neighbor is more precious than our temporal goods.

I suppose 2° that where the common good is at stake, and the life of persons necessary to the republic, anyone can and is bound to expose his own life for preserving its life.

I suppose 3° that where the lives are equal, if I believe myself to be in mortal sin, or if my life is necessary to my family or others, it is not lawful for me to expose my life for the life of another. These things supposed,

I answer. It is not lawful to expose one's own life for the life of another equal considered precisely in itself, or looking precisely at life and life; for that would be to love one's neighbor not as oneself, but more than oneself, which is against the order of charity. More probably, however, it is lawful out of a motive of Christian virtue.

Proof. this second part from the words of Christ, John., XV, 13: Greater love than this no one has, than that he lay down his life for his friends; which can be understood generally also of bodily welfare, as Chrysostom understood it, book II de Sacerd. Besides, it is lawful to prefer the good of virtue to the good of the body, where necessity so requires.

From this probable opinion many theologians infer that, if two men are in extreme necessity, one may give to the other the only bread he has; in flight from enemies he may give up his horse, though he cannot flee on foot; with plague raging, he may serve the sick; in shipwreck, he may yield the plank which he could occupy, or already has occupied: provided however he has not yet begun to use it; for in this case, says Sylvius, to yield the plank would be to throw oneself into the sea, which seems to belong to the killing of oneself, which is never lawful.]