Summa Theologica, by St. Thomas Aquinas, , at sacred-texts.com
We must now consider the sin of blasphemy, which is opposed to the confession of faith; and (1) blasphemy in general, (2) that blasphemy which is called the sin against the Holy Ghost.
Under the first head there are four points of inquiry:
(1) Whether blasphemy is opposed to the confession of faith?
(2) Whether blasphemy is always a mortal sin?
(3) Whether blasphemy is the most grievous sin?
(4) Whether blasphemy is in the damned?
Objection 1: It would seem that blasphemy is not opposed to the confession of faith. Because to blaspheme is to utter an affront or insult against the Creator. Now this pertains to ill-will against God rather than to unbelief. Therefore blasphemy is not opposed to the confession of faith.
Objection 2: Further, on Eph. 4:31, "Let blasphemy . . . be put away from you," a gloss says, "that which is committed against God or the saints." But confession of faith, seemingly, is not about other things than those pertaining to God, Who is the object of faith. Therefore blasphemy is not always opposed to the confession of faith.
Objection 3: Further, according to some, there are three kinds of blasphemy. The first of these is when something unfitting is affirmed of God; the second is when something fitting is denied of Him; and the third, when something proper to God is ascribed to a creature, so that, seemingly, blasphemy is not only about God, but also about His creatures. Now the object of faith is God. Therefore blasphemy is not opposed to confession of faith.
On the contrary, The Apostle says (1 Tim. 1:12, 13): "I . . . before was a blasphemer and a persecutor," and afterwards, "I did it ignorantly in" my "unbelief." Hence it seems that blasphemy pertains to unbelief.
I answer that, The word blasphemy seems to denote the disparagement of some surpassing goodness, especially that of God. Now God, as Dionysius says (Div. Nom. i), is the very essence of true goodness. Hence whatever befits God, pertains to His goodness, and whatever does not befit Him, is far removed from the perfection of goodness which is His Essence. Consequently whoever either denies anything befitting God, or affirms anything unbefitting Him, disparages the Divine goodness.
Now this may happen in two ways. In the first way it may happen merely in respect of the opinion in the intellect; in the second way this opinion is united to a certain detestation in the affections, even as, on the other hand, faith in God is perfected by love of Him. Accordingly this disparagement of the Divine goodness is either in the intellect alone, or in the affections also. If it is in thought only, it is blasphemy of the heart, whereas if it betrays itself outwardly in speech it is blasphemy is opposed to confession of faith.
Reply to Objection 1: He that speaks against God, with the intention of reviling Him, disparages the Divine goodness, not only in respect of the falsehood in his intellect, but also by reason of the wickedness of his will, whereby he detests and strives to hinder the honor due to God, and this is perfect blasphemy.
Reply to Objection 2: Even as God is praised in His saints, in so far as praise is given to the works which God does in His saints, so does blasphemy against the saints, redound, as a consequence, against God.
Reply to Objection 3: Properly speaking, the sin of blasphemy is not in this way divided into three species: since to affirm unfitting things, or to deny fitting things of God, differ merely as affirmation and negation. For this diversity does not cause distinct species of habits, since the falsehood of affirmations and negations is made known by the same knowledge, and it is the same ignorance which errs in either way, since negatives are proved by affirmatives, according to Poster. i, 25. Again to ascribe to creatures things that are proper to God, seems to amount to the same as affirming something unfitting of Him, since whatever is proper to God is God Himself: and to ascribe to a creature, that which is proper to God, is to assert that God is the same as a creature.
Objection 1: It would seem that blasphemy is not always a mortal sin. Because a gloss on the words, "Now lay you also all away," etc. (Col. 3:8) says: "After prohibiting greater crimes he forbids lesser sins": and yet among the latter he includes blasphemy. Therefore blasphemy is comprised among the lesser, i.e. venial, sins.
Objection 2: Further, every mortal sin is opposed to one of the precepts of the decalogue. But, seemingly, blasphemy is not contrary to any of them. Therefore blasphemy is not a mortal sin.
Objection 3: Further, sins committed without deliberation, are not mortal: hence first movements are not mortal sins, because they precede the deliberation of the reason, as was shown above (FS, Q, AA,10). Now blasphemy sometimes occurs without deliberation of the reason. Therefore it is not always a mortal sin.
On the contrary, It is written (Lev. 24:16): "He that blasphemeth the name of the Lord, dying let him die." Now the death punishment is not inflicted except for a mortal sin. Therefore blasphemy is a mortal sin.
I answer that, As stated above (FS, Q, A), a mortal sin is one whereby a man is severed from the first principle of spiritual life, which principle is the charity of God. Therefore whatever things are contrary to charity, are mortal sins in respect of their genus. Now blasphemy, as to its genus, is opposed to Divine charity, because, as stated above (A), it disparages the Divine goodness, which is the object of charity. Consequently blasphemy is a mortal sin, by reason of its genus.
Reply to Objection 1: This gloss is not to be understood as meaning that all the sins which follow, are mortal, but that whereas all those mentioned previously are more grievous sins, some of those mentioned afterwards are less grievous; and yet among the latter some more grievous sins are included.
Reply to Objection 2: Since, as stated above (A), blasphemy is contrary to the confession of faith, its prohibition is comprised under the prohibition of unbelief, expressed by the words: "I am the Lord thy God," etc. (Ex. 20:1). Or else, it is forbidden by the words: "Thou shalt not take the name of . . . God in vain" (Ex. 20:7). Because he who asserts something false about God, takes His name in vain even more than he who uses the name of God in confirmation of a falsehood.
Reply to Objection 3: There are two ways in which blasphemy may occur unawares and without deliberation. In the first way, by a man failing to advert to the blasphemous nature of his words, and this may happen through his being moved suddenly by passion so as to break out into words suggested by his imagination, without heeding to the meaning of those words: this is a venial sin, and is not a blasphemy properly so called. In the second way, by adverting to the meaning of his words, and to their blasphemous nature: in which case he is not excused from mortal sin, even as neither is he who, in a sudden movement of anger, kills one who is sitting beside him.
Objection 1: It would seem that the sin of blasphemy is not the greatest sin. For, according to Augustine (Enchiridion xii), a thing is said to be evil because it does harm. Now the sin of murder, since it destroys a man's life, does more harm than the sin of blasphemy, which can do no harm to God. Therefore the sin of murder is more grievous than that of blasphemy.
Objection 2: Further, a perjurer calls upon God to witness to a falsehood, and thus seems to assert that God is false. But not every blasphemer goes so far as to say that God is false. Therefore perjury is a more grievous sin than blasphemy.
Objection 3: Further, on Ps. 74:6, "Lift not up your horn on high," a gloss says: "To excuse oneself for sin is the greatest sin of all." Therefore blasphemy is not the greatest sin.
On the contrary, On Is. 18:2, "To a terrible people," etc. a gloss says: "In comparison with blasphemy, every sin is slight."
I answer that, As stated above (A), blasphemy is opposed to the confession of faith, so that it contains the gravity of unbelief: while the sin is aggravated if the will's detestation is added thereto, and yet more, if it breaks out into words, even as love and confession add to the praise of faith.
Therefore, since, as stated above (Q, A), unbelief is the greatest of sins in respect of its genus, it follows that blasphemy also is a very great sin, through belonging to the same genus as unbelief and being an aggravated form of that sin.
Reply to Objection 1: If we compare murder and blasphemy as regards the objects of those sins, it is clear that blasphemy, which is a sin committed directly against God, is more grave than murder, which is a sin against one's neighbor. On the other hand, if we compare them in respect of the harm wrought by them, murder is the graver sin, for murder does more harm to one's neighbor, than blasphemy does to God. Since, however, the gravity of a sin depends on the intention of the evil will, rather than on the effect of the deed, as was shown above (FS, Q, A), it follows that, as the blasphemer intends to do harm to God's honor, absolutely speaking, he sins more grievously that the murderer. Nevertheless murder takes precedence, as to punishment, among sins committed against our neighbor.
Reply to Objection 2: A gloss on the words, "Let . . . blasphemy be put away from you" (Eph. 4:31) says: "Blasphemy is worse than perjury." The reason is that the perjurer does not say or think something false about God, as the blasphemer does: but he calls God to witness to a falsehood, not that he deems God a false witness, but in the hope, as it were, that God will not testify to the matter by some evident sign.
Reply to Objection 3: To excuse oneself for sin is a circumstance that aggravates every sin, even blasphemy itself: and it is called the most grievous sin, for as much as it makes every sin more grievous.
Objection 1: It would seem that the damned do not blaspheme. Because some wicked men are deterred from blaspheming now, on account of the fear of future punishment. But the damned are undergoing these punishments, so that they abhor them yet more. Therefore, much more are they restrained from blaspheming.
Objection 2: Further, since blasphemy is a most grievous sin, it is most demeritorious. Now in the life to come there is no state of meriting or demeriting. Therefore there will be no place for blasphemy.
Objection 3: Further, it is written (Eccles. 11:3) that "the tree . . . in what place soever it shall fall, there shall it be": whence it clearly follows that, after this life, man acquires neither merit nor sin, which he did not already possess in this life. Now many will be damned who were not blasphemous in this life. Neither, therefore, will they blaspheme in the life to come.
On the contrary, It is written (Apoc. 16:9): "The men were scorched with great heat, and they blasphemed the name of God, Who hath power over these plagues," and a gloss on these words says that "those who are in hell, though aware that they are deservedly punished, will nevertheless complain that God is so powerful as to torture them thus." Now this would be blasphemy in their present state: and consequently it will also be in their future state.
I answer that, As stated above (AA,3), detestation of the Divine goodness is a necessary condition of blasphemy. Now those who are in hell retain their wicked will which is turned away from God's justice, since they love the things for which they are punished, would wish to use them if they could, and hate the punishments inflicted on them for those same sins. They regret indeed the sins which they have committed, not because they hate them, but because they are punished for them. Accordingly this detestation of the Divine justice is, in them, the interior blasphemy of the heart: and it is credible that after the resurrection they will blaspheme God with the tongue, even as the saints will praise Him with their voices.
Reply to Objection 1: In the present life men are deterred from blasphemy through fear of punishment which they think they can escape: whereas, in hell, the damned have no hope of escape, so that, in despair, they are borne towards whatever their wicked will suggests to them.
Reply to Objection 2: Merit and demerit belong to the state of a wayfarer, wherefore good is meritorious in them, while evil is demeritorious. In the blessed, on the other hand, good is not meritorious, but is part of their blissful reward, and, in like manner, in the damned, evil is not demeritorious, but is part of the punishment of damnation.
Reply to Objection 3: Whoever dies in mortal sin, bears with him a will that detests the Divine justice with regard to a certain thing, and in this respect there can be blasphemy in him.