The Catechetical Instructions of St. Thomas

Author: Aquinas



I. I am the Lord thy God, who brought thee out of the land of Egypt, out of the house of bondage. Thou shalt not have strange gods before Me. Thou shalt not make to thyself a graven thing, nor the likeness of any thing that is in heaven above, or in the earth beneath, nor of those things that are in the waters under the earth. Thou shalt not adore them, nor serve them. I am the Lord thy God, mighty, jealous, visiting the iniquity of the fathers upon the children, unto the third and fourth generation of them that hate Me; and showing mercy unto thousands of them that love Me, and keep My commandments.

II. Thou shalt not take the name of the Lord thy God in vain.

III. Remember that thou keep holy the Sabbath day.

IV. Honor thy father and thy mother.

V. Thou shalt not kill.

VI. Thou shalt not commit adultery.

VII. Thou shalt not steal.

VIII. Thou shalt not bear false witness against thy neighbor.

IX. Thou shalt not covet thy neighbor's wife.

X. Thou shalt not covet thy neighbor's house, nor his field, nor his servant, nor his handmaid, nor his ox, nor his ass, nor anything that is his.[1]


1. Exod., xx. 2-17, and Deut., v. 6-21.

THE FIRST COMMANDMENT: "Thou Shalt Not Have Strange Gods Before Me."

The entire law of Christ depends upon charity. And charity depends on two precepts, one of which concerns loving God and the other concerns loving our neighbor.

Now God, in delivering the law to Moses, gave him Ten Commandments written upon two tablets of stone. Three of these Commandments that were written on the first tablet referred to the love of God; and the seven Commandments written on the other tablet related to the love of our neighbor. The whole law, therefore, is founded on these two precepts.[1]

The First Commandment which relates to the love of God is: "Thou shalt not have strange gods." For an understanding of this Commandment, one must know how of old it was violated. Some worshipped demons. "All the gods of the Gentiles are devils."[2] This is the greatest and most detestable of all sins. Even now there are many who transgress this Commandment: all such as practise divinations and fortune-telling. Such things, according to St. Augustine, cannot be done without some kind of pact with the devil. "I would not that you should be made partakers with devils."[3]

Some worshipped the heavenly bodies, believing the stars to be gods: "They have imagined the sun and the moon to be the gods that rule the world."[4] For this reason Moses forbade the Jews to raise their eyes, or adore the sun and moon and stars: "Keep therefore your souls carefully . . . lest perhaps lifting up thy eyes to heaven, thou see the sun and the moon, and all the stars of heaven, and being deceived by error thou adore and serve them, which the Lord thy God created for the service of all the nations."[5] The astrologers sin against this Commandment in that they say that these bodies are the rulers of souls, when in truth they were made for the use of man whose sole ruler is God.

Others worshipped the lower elements: "They imagined the fire or the wind to be gods."[6] Into this error also fall those who wrongly use the things of this earth and love them too much: "Or covetous person (who is a server of idols)."[7]

Some men have erred in worshipping their ancestors. This arose from three causes.

(1) From Their Carnal Nature.--"For a father being afflicted with a bitter grief, made to himself the image of his son who was quickly taken away; and him who then had died as a man, he began now to worship as a god, and appointed him rites and sacrifices among his servants."[8]

(2) Because of Flattery.--Thus being unable to worship certain men in their presence, they, bowing down, honored them in their absence by making statues of them and worshipping one for the other: "Whom they had a mind to honor . . . they made an image . . . that they might honor as present him that was absent."[9] Of such also are those men who love and honor other men more than God: "He that loveth his father and mother more than Me, is not worthy of Me."[10] "Put your trust not in princes; in the children of man, in whom there is no salvation."[11]

(3) From Presumption.--Some because of their presumption made themselves be called gods; such, for example, was Nabuchodonosor (Judith, iii. 13). "Thy heart is lifted up and thou hast said: I am God."[12] Such are also those who believe more in their own pleasures than in the precepts of God. They worship themselves as gods, for by seeking the pleasures of the flesh, they worship their own bodies instead of God: "Their god is their belly."[13] We must, therefore, avoid all these things.


"Thou shalt not have strange gods before Me." As we have already said, the First Commandment forbids us to worship other than the one God. We shall now consider five reasons for this.

God's Dignity.--The first reason is the dignity of God which, were it belittled-in any way, would be an injury to God. We see something similar to this in the customs of men. Reverence is due to every degree of dignity. Thus, a traitor to the king is he who robs him of what he ought to maintain. Such, too, is the conduct of some towards God: "They changed the glory of the incorruptible God into the likeness of the image of a corruptible man."[14] This is highly displeasing to God: "I will not give My glory to another, nor My praise to graven things."[15] For it must be known that the dignity of God consists in His omniscience, since the name of God, Deus, is from "seeing," and this is one of the signs of divinity: "Show the things that are to come hereafter, and we shall know that ye are gods."[16] "All things are naked and open to His eyes."[17] But this dignity of God is denied Him by practitioners of divination, and of them it is said: "Should not the people seek of their God, for the living and the dead?"[18]

God's Bounty.--We receive every good from God; and this also is of the dignity of God, that He is the maker and giver of all good things: "When Thou openest Thy hand, they shall all be filled with good."[13] And this is implied in the name of God, namely, Deus, which is said to be distributor, that is, "dator" of all things, because He fills all things with His goodness. You are, indeed, ungrateful if you do not appreciate what you have received from Him, and, furthermore, you make for yourself another god; just as the sons of Israel made an idol after they had been brought out of Egypt: "I will go after my lovers."[20] One does this also when one puts too much trust in someone other than God, and this occurs when one seeks help from another: "Blessed is the man whose hope is in the name of the Lord."[21] Thus, the Apostle says: "Now that you have known God . . . how turn you again to the weak and needy elements? . . . You observe days and months and times and years."[22]

The Strength of Our Promise.--The third reason is taken from our solemn promise. For we have renounced the devil, and we have promised fidelity to God alone. This is a promise which we cannot break: "A man making void the law of Moses dieth without mercy under two or three witnesses. How much more think ye he deserveth punishment who hath trodden under foot the Son of God, and hath esteemed the blood of the testament unclean, by which he was sanctified, and hath offered an affront to the Spirit of grace!"[23] "Whilst her husband liveth, she shall be called an adulteress, if she be with another man."[24] Woe, then, to the sinner who enters the land by two ways, and who "halts between two sides."[25]

Against Service of the Devil.--The fourth reason is because of the great burden imposed by service to the devil: "You shall serve strange gods day and night, who will give you no rest."[26] The devil is not satisfied with leading to one sin, but tries to lead on to others: "Whosoever sins shall be a slave of sin."[27] It is, therefore, not easy for one to escape from the habit of sin. Thus, St. Gregory says: "The sin which is not remitted by penance soon draws man into another sin."[28] The very opposite of all this is true of service to God; for His Commandments are not a heavy burden: "My yoke is sweet and My burden light."[29] A person is considered to have done enough if he does for God as much as what he has done for the sake of sin: "For as you have yielded your members to serve uncleanness and iniquity, unto iniquity; so now yield your members to serve justice unto sanctification."[30] But on the contrary, it is written of those who serve the devil: "We wearied ourselves in the way of iniquity and destruction, and have walked through hard ways."[31] And again: "They have labored to commit iniquity."[32]

Greatness of the Reward.--The fifth reason is taken from the greatness of the reward or prize. In no law are such rewards promised as in the law of Christ. Rivers flowing with milk and honey are promised to the Mohammedans, to the Jews the land of promise, but to Christians the glory of the Angels: "They shall be as the Angels of God in heaven."[33] It was with this in mind that St. Peter asked: "Lord, to whom shall we go? Thou hast the words of eternal life."[34]

(For "Questions for Discussion" see Chapter 6.)


1. "The Decalogue is the summary and epitome of the entire law of God," is the opinion of St. Augustine (Quest. cxl super Exod., lib. ii). "Although the Lord had spoken many things, yet He gave only two tablets of stone to Moses. . . . If carefully examined and well understood, it will be found that on them depend whatever else is commanded by God. Again, these ten commandments are reducible to two, the love of God and our neighbor, on which 'depend the whole law and the prophets' " ("Roman Catechism," "The Decalogue," Chapter I, 1).

2. Ps. xcv. 5

3. I Cor., x. 20.

4. Wis., xiii. 2.

5. Deut., iv. 15, 19.

6. Wis., xiii. 2.

7. Eph., v. 5.

8. Wis., xiv. 15.

9. "Ibid.," 17.

10. Matt., x. 37.

11. Ps. cxlv. 3.

12. Ezech., xxviii. 2.

13. Phil., iii. 19.

14. Rom., i. 23.

15. Isa., xlii. 8.

16. "Ibid.," xli. 23.

17. Heb., iv. 13.

18. Isa., viii. 19.

19. Ps. ciii. 28.

20. Osee, ii. 5.

21. Ps. xxxix. 5.

22. Gal., iv. 9, 10.

23. Heb., x. 28-29.

24. Rom., vii. 3.

25. III Kings, xviii. 21.

26. Jerem., xvi. 13.

27. John, viii.

28. "Super Ezech.," xi.

29. Matt., xi. 30.

30. Rom., vi. 19.

31. Wis., v. 7.

32. Jerem., ix. 5.

33. Matt., xxii, 30.

34. John, vi. 69. "The faithful should continually remember these words, 'I am the Lord thy God.' They will learn from these words that their Lawgiver is none other than their Creator, by whom they were made and are preserved. . . . 'Who brought thee out of the land of Egypt, out of the house of bondage' appear at first to relate solely to the Jews liberated from the bondage of Egypt. But if we ponder on the meaning of the salvation of the entire human race, these words will be seen to apply still more specifically to all Christians who are liberated by God, not from the bondage ot Egypt, but from the bondage of sin and 'the powers of darkness, and are translated into the kingdom of His beloved Son' (Col., i. 13). . . . And when it is said, 'Thou shalt not have strange gods before Me,' it is the same as to say: 'Thou shalt worship Me who am the true God, thou shalt not worship strange gods.' . . . It should be accurately taught that the veneration and invocation of the Angels, of the Saints, and of the blessed souls who enjoy the glory of heaven--and, moreover, the honor which the Catholic Church has always paid even to the bodies and ashes of the Saints- -are not forbidden by this Commandment" ("Roman Catechism," "First Commandment," 1, 2, 5, 8).

SECOND COMMANDMENT: "Thou Shalt Not Take the Name of the Lord Thy God in Vain."

This is the Second Commandment of the law. Just as there is but one God whom we must worship, so there is only one God whom we should reverence in a special manner. This, first of all, has reference to the name of God. "Thou shalt not take the name of the Lord thy God in vain."[1]


"In vain" has a threefold meaning. Sometimes it is said of that which is false: "They have spoken vain things every one to his neighbor."[2] One, therefore, takes the name of God in vain when one uses it to confirm that which is not true: "Love not a false oath."[3] "Thou shalt not live because thou hast spoken a lie in the name of the Lord."[4] Any one so doing does injury to God, to himself, and to all men.

It is an insult to God because, when you swear by God, it is nothing other than to call Him to witness; and when you swear falsely, you either believe God to be ignorant of the truth and thus place ignorance in God, whereas "all things are naked and open to His eyes,"[5] or you think that God loves a lie, whereas He hates it: "Thou wilt destroy all that speak a lie."[6] Or, again, you detract from His power, as if He were not able to punish a lie.

Likewise, such a one does an injury to himself, for he binds himself to the judgment of God. It is the same thing to say, "By God this is so," as to say, "May God punish me if it is not so!"

He, finally, does an injury to other men. For there can be no lasting society unless men believe one another. Matters that are doubtful may be confirmed by oaths: "An oath in confirmation puts an end to all controversy."[7] Therefore, he who violates this precept does injury to God, is cruel to himself, and harmful to other men.

Sometimes "vain" signifies useless: "The Lord knoweth the thoughts of men, that they are vain."[8] God's name, therefore, is taken in vain when it is used to confirm vain things.

In the Old Law it was forbidden to swear falsely: "Thou shalt not take the name of the Lord thy God in vain."[9] And Christ forbade the taking of oaths except in case of necessity: "You have heard that it was said to them of old: Thou shalt not forswear thyself. . . . But I say to you not to swear at all."[10] And the reason for this is that in no part of our body are we so weak as in the tongue, for "the tongue no man can tame."[11] And thus even in light matter one can perjure himself. "Let your speech be: Yea, yea; No, no. But I say to you not to swear at all."[12]

Note well that an oath is like medicine, which is never taken continually but only in times of necessity. Hence, the Lord adds: "And that which is over and above these is evil."[13] "Let not the mouth be accustomed to swearing, for in it there are many falls. And let not the name of God be usual in thy mouth, and meddle not with the names of saints. For thou shalt not escape free from them."[14]

Sometimes "in vain" means sin or injustice: "O ye sons of men, how long will you be dull of heart? Why do you love vanity?"[15] Therefore, he who swears to commit a sin, takes the name of his God in vain. Justice consists in doing good and avoiding evil. Therefore, if you take an oath to steal or commit some crime of this sort, you sin against justice. And although you must not keep this oath, you are still guilty of perjury. Herod did this against John.[16] It is likewise against justice when one swears not to do some good act, as not to enter a church or a religious community. And although this oath, too, is not binding, yet, despite this, the person himself is a perjuror.


One cannot, therefore, swear to a falsehood, or without good reason, or in any way against justice: "And thou shalt swear: As the Lord liveth, in truth, and in judgment and in justice."[17]

Sometimes "vain" also means foolish: "All men are vain, in whom there is not the knowledge of God."[18] Accordingly, he who takes the name of God foolishly, by blasphemy, takes the name of God in vain: "And he that blasphemeth the name of the Lord, dying let him die."[19]


"Thou shalt not take the name of the Lord thy God in vain." However, the name of God may be taken for six purposes. First, to confirm something that is said, as in an oath. In this we show God alone is the first Truth, and also we show due reverence to God. For this reason it was commanded in the Old Law that one must not swear except by God.[20] They who swore otherwise violated this order: "By the name of strange gods you shall not swear."[21] Although at times one swears by creatures, nevertheless, it must be known that such is the same as swearing by God. When you swear by your soul or your head, it is as if you bind yourself to be punished by God. Thus: "But I call God to witness upon my soul."[22] And when you swear by the Gospel, you swear by God who gave the Gospel. But they sin who swear either by God or by the Gospel for any trivial reason.

The second purpose is that of sanctification. Thus, Baptism sanctifies, for as St. Paul says: "But you are washed, but you are sanctified, but you are justified in the name of our Lord Jesus Christ, and the Spirit of God."[23] Baptism, however, does not have power except through the invocation of the Trinity: "But Thou, O Lord, art among us, and Thy name is called upon by us."[24]

The third purpose is the expulsion of our adversary; hence, before Baptism we renounce the devil: "Only let Thy name be called upon us; take away our reproach.[25] Wherefore, if one return to his sins, the name of God has been taken in vain.

Fourthly, God's name is taken in order to confess it: "How then shall they call on Him, in whom they have not believed?"[26] And again: "Whosoever shall call upon the name of the Lord, shall be saved."[27] First of all, we confess by word of mouth that we may show forth the glory of God: "And every one that calleth upon My name, I have created him for My glory."[28] Accordingly, if one says anything against the glory of God, he takes the name of God in vain. Secondly, we confess God's name by our works, when our very actions show forth God's glory: "That they may see your good works, and may glorify your Father who is in heaven."[29] "Through you the name of God is blasphemed among the Gentiles."[30]

Fifthly it is taken for our defense: "The name of the Lord is a strong tower; the just runneth to it and shall be exalted."[31] "In My name they shall cast out devils."[32] "There is no other name under heaven given to men, whereby we must be saved.[33]

Lastly, it is taken in order to make our works complete. Thus says the Apostle: "All whatsoever you do in word or work, do all in the name of the Lord Jesus Christ."[34] The reason is because "our help is in the name of the Lord."[35] Sometimes it happens that one begins a work imprudently by starting with a vow, for instance, and then not completing either the work or the vow. And this again is taking God's name in vain. "If thou hast vowed anything to God, defer not to pay it."[36] "Vow and pay to the Lord your God; all ye that are round about Him bring presents."[37] "For an unfaithful and foolish promise displeaseth Him."[38]

(For "Questions for Discussion" see Chapter 6.)


1. "He who requires that honor be paid Him, also demands that we speak of Him with reverence, and He forbids the contrary. . . . There are those who are so blinded by darkness of error as not to fear to blaspheme His name, whom the Angels glorify. Men are not deterred by this Commandment from shamelessly and daringly outraging His divine majesty every day, or rather every hour and moment of the day. Who does not know that every assertion is accompanied with an oath and teems with curses and imprecations? To such lengths has this impiety been carried that one scarcely buys or sells, or transacts ordinary business of any sort, without having recourse to swearing, and who, even in matters the most unimportant and trivial, does not profane the most holy name of God thousands of times" ("Roman Catechism," "Second Commandment," 2). See also teaching of St. Thomas in "Summa Theol.," II-II, Q. lxxxix, art. 3, 5, 6.

2. Ps. xi. 3.

3. Zach, viii. 17.

4. "Ibid.," xiii. 3.

5. Heb., iv. 13.

6. Ps. v. 7.

7. Heb., vi. 16.

8. Ps. xciii. 11.

9. Deut., v. 11.

10. Matt., v. 33-34.

11. James, iii. 8.

12. Matt., v. 34, 37. "It cannot be stated that these words condemn oaths universally and under all circumstances, since the Apostles and Our Lord Himself made frequent use of oaths (Deut., vi. 13; Ps. lxii. 12; II Cor., i. 23; Philem., 8; Apoc., x. 6). The object of the Lord was rather to reprove the perverse opinion of the Jews, which was to the effect that the only thing to be avoided in an oath was a lie. . . . For oaths have been instituted on account of human frailty. They bespeak the inconstancy of him who takes it or the stubbornness of him who refuses to believe without it. However, an oath can be justified by necessity. When Our Lord says, 'Let your speech be: Yea, yea; No, no,' He evidently forbids the habit of swearing in familiar conversation and on trivial matters" ("Roman Catechism," "loc. cit.," 19).

13. Matt., v. 37.

14. Ecclus., xxiii. 9, 10.

15. Ps. iv. 3.

16. Mark, vi.

17. Jerem., iv. 2. Although to constitute an oath it is sufficient to call God to witness, yet to make a holy and just oath many other conditions are required. . . . The words [of Jeremias, cited above] briefly sum up all the conditions that constitute the perfection of an oath, namely, truth, judgment, justice ("Roman Catechism., "loc. cit.," 11).

18. Wis., xiii. 1.

19. Levit., xxiv. 16.

20. Deut., vi. 13.

21. Exod., xxiii. 13.

22. Cor., i. 23.

23. I Cor., vi. 11.

24. Jerem., xiv. 9.

25. Isa., iv. 1.

26. Rom., x. 14.

27. "Ibid.," 13.

28. Isa., xliii. 7.

29. Matt., v. 16.

30. Rom., ii. 24.

31. Prov., xviii. 10.

32. Mark, xvi. 17.

33. Acts, iv. 12.

34. Col., iii. 17.

35. Ps. cxxiii. 8.

36. Eccles., v. 3.

37. Ps. lxxv. 12.

38. Eccles., v. 3.

THE THIRD COMMANDMENT: "Remember that You Keep Holy the Sabbath Day."

This is the Third Commandment of the law, and very suitably is it so. For we are first commanded to adore God in our hearts, and the Commandment is to worship one God: "Thou shalt not have strange gods before Me." In the Second Commandment we are told to reverence God by word: "Thou shalt not take the name of the Lord thy God in vain." The Third commands us to reverence God by act. It is: "Remember that thou keep holy the Sabbath day."[1] God wished that a certain day be set aside on which men direct their minds to the service of the Lord.


There are five reasons for this Commandment. The first reason was to put aside error, for the Holy Spirit saw that in the future some men would say that the world had always existed. "In the last days there shall come deceitful scoffers, walking after their own lusts, saying: Where is His promise or His coming? For since the time that the fathers slept, all things continue as they were from the beginning of creation. For this they are willfully ignorant of, that the heavens were before, and the earth out of water, and through water, created by the word of God."[2] God, therefore, wished that one day should be set aside in memory of the fact that He created all things in six days, and that on the seventh day He rested from the creation of new creatures. This is why the Lord placed this Commandment in the law, saying: "Remember that thou keep holy the Sabbath day."

The Jews kept holy the Sabbath in memory of the first creation; but Christ at His coming brought about a new creation. For by the first creation an earthly man was created, and by the second a heavenly man was formed: "For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but a new creature."[3] This new creation is through grace, which came by the Resurrection: "That as Christ is risen from the dead by the glory of the Father, so we also may walk in newness of life. For if we have been planted together in the likeness of His death, so shall we also be in the likeness of His resurrection."[4] And thus, because the Resurrection took place on Sunday, we celebrate that day, even as the Jews observed the Sabbath on account of the first creation.[5]

The second reason for this Commandment is to instruct us in our faith in the Redeemer. For the flesh of Christ was not corrupted in the sepulchre, and thus it is said: "Moreover My flesh also shall rest in hope."[6] "Nor wilt Thou give Thy holy one to see corruption."[7] Wherefore, God wished that the Sabbath should be observed, and that just as the sacrifices of the Old Law signified the death of Christ, so should the quiet of the Sabbath signify the rest of His body in the sepulchre. But we do not now observe these sacrifices, because with the advent of the reality and the truth, figures of it must cease, just as the darkness is dispelled with the rising of the sun. Nevertheless, we keep the Saturdays in veneration of the Blessed Virgin, in whom remained a firm faith on that Saturday while Christ was dead.

The third reason is that this Commandment was given to strengthen and foreshadow the fulfillment of the promise of rest. For rest indeed was promised to us: "And it shall come to pass on that day, that when God shall give thee rest from thy labor, and from thy vexation, and from the hard bondage, wherewith thou didst serve before."[8] "My people shall sit in the beauty of peace, and in the tabernacle of confidence, and in wealthy rest."[9]

We hope for rest from three things: from the labors of the present life, from the struggles of temptations, and from the servitude of the devil. Christ promised this rest to all those who will come to Him: "Come to Me, all ye that labor and are burdened, and I will refresh you. Take up My yoke upon you, and learn of Me, because I am meek and humble of heart; and you shall find rest to your souls. For My yoke is sweet and My burden light."[10]

However, the Lord, as we know, worked for six days and on the seventh He rested, because it is necessary to do a perfect work: "Behold with your eyes how I have labored a little, and have found much rest to Myself."[11] For the period of eternity exceeds the present time incomparably more than a thousand years exceeds one day.

Fourthly, this Commandment was given for the increase of our love: "For the corruptible body is a load upon the soul."[12] And man always tends downwards towards earthly things unless he takes means to raise himself above them. It is indeed necessary to have a certain time for this; in fact, some do this continually: "I will bless the Lord at all times, His praise shall ever be in my mouth."[13] And again: "Pray without ceasing."[14] These shall enjoy the everlasting Sabbath. There are others who do this (i.e., excite love for God) during a certain portion of the day: "Seven times a day I have given praise to Thee."[15] And some, in order to avoid being entirely apart from God, find it necessary to have a fixed day, lest they become too lukewarm in their love of God: "If you call the Sabbath delightful . . . then shalt thou be delighted in the Lord."[16] Again: "Then shalt thou abound in delights of the Almighty, and shalt lift up thy face to God."[17] And accordingly this day is not set aside for the sole exercise of games, but to praise and pray to the Lord God. Wherefore, St. Augustine says that it is a lesser evil to plough than to play on this day.[18]

Lastly, we are given this Commandment in order to exercise works of kindliness to those who are subject to us. For some are so cruel to themselves and to others that they labor ceaselessly all on account of money. This is true especially of the Jews, who are most avaricious. "Observe the day of the Sabbath to sanctify it . . . that thy man-servant and thy maid-servant may rest, even as thyself."[19] This Commandment, therefore, was given for all these reasons.


"Remember that you keep holy (sanctify) the Sabbath day." We have already said that, as the Jews celebrated the Sabbath, so do we Christians observe the Sunday and all principal feasts. Let us now see in what way we should keep these days. We ought to know that God did not say to "keep" the Sabbath, but to remember to keep it holy. The word "holy" may be taken in two ways. Sometimes "holy" (sanctified) is the same as pure: "But you are washed, but you are sanctified"[20] (that is, made holy). Then again at times "holy" is said of a thing consecrated to the worship of God, as, for instance, a place, a season, vestments, and the holy vessels. Therefore, in these two ways we ought to celebrate the feasts, that is, both purely and by giving ourselves over to divine service.

We shall consider two things regarding this Commandment. First, what should be avoided on a feast day, and secondly, what we should do. We ought to avoid three things. The first is servile work.

Avoidance of Servile Work.--"Neither do ye any work; sanctify the Sabbath day."[21] And so also it is said in the Law: "You shall do no servile work therein."[22] Now, servile work is bodily work; whereas "free work" (i.e., non-servile work) is done by the mind, for instance, the exercise of the intellect and such like. And one cannot be servilely bound to do this kind of work.

When Servile Work Is Lawful.--We ought to know, however, that servile work can be done on the Sabbath for four reasons. The first reason is necessity. Wherefore, the Lord excused the disciples plucking the ears of corn on the Sabbath, as we read in St. Matthew (xii. 3-5). The second reason is when the work is done for the service of the Church; as we see in the same Gospel how the priests did all things necessary in the Temple on the Sabbath day. The third reason is for the good of our neighbor; for on the Sabbath the Saviour cured one having a withered hand, and He refuted the Jews who reprimanded Him, by citing the example of the sheep in a pit ("ibid."). And the fourth reason is the authority of our superiors. Thus, God commanded the Jews to circumcise on the Sabbath.[13]

Avoidance of Sin and Negligence on the Sabbath.--Another thing to be avoided on the Sabbath is sin: "Take heed to your souls, and carry no burdens on the Sabbath day."[24] This weight and burden on the soul is sin: "My iniquities as a heavy burden are become heavy upon me."[25] Now, sin is a servile work because "whosoever committeth sin is the servant of sin."[26] Therefore, when it is said, "You shall do no servile work therein,"[27] it can be understood of sin. Thus, one violates this commandment as often as one commits sin on the Sabbath; and so both by working and by sin God is offended.[28] "The Sabbaths and other festivals I will not abide." And why? "Because your assemblies are wicked. My soul hateth your new moon[29] and your solemnities; they are become troublesome to me."[30]

Another thing to avoid on the Sabbath is idleness: "For idleness hath taught much evil."[31] St. Jerome says: "Always do some good work, and the devil will always find you occupied."[32] Hence, it is not good for one to keep only the principal feasts, if on the others one would remain idle. "The King's honor loveth judgment,"[33] that is to say, discretion. Wherefore, we read that certain of the Jews were in hiding, and their enemies fell upon them; but they, believing that they were not able to defend themselves on the Sabbath, were overcome and killed.[34] The same thing happens to many who are idle on the feast days: "The enemies have seen her, and have mocked at her Sabbaths."[35] But all such should do as those Jews did, of whom it is said: "Whosoever shall come up against us to fight on the Sabbath day, we will fight against him."[36]


"Remember that thou keep holy the Sabbath day." We have already said that man must keep the feast days holy; and that "holy" is considered in two ways, namely, "pure" and "consecrated to God." Moreover, we have indicated what things we should abstain from on these days. Now it must be shown with what we should occupy ourselves, and they are three in number.

The Offering of Sacrifice.--The first is the offering of sacrifices.[37] In the Book of Numbers (xxviii) it is written how God ordered that on each day there be offered one lamb in the morning and another in the evening, but on the Sabbath day the number should be doubled. And this showed that on the Sabbath we should offer sacrifice to God from all that we possess: "All things are Thine; and we have given Thee what we received from Thy hand."[38] We should offer, first of all, our soul to God, being sorry for our sins: "A sacrifice to God is an afflicted spirit;"[39] and also pray for His blessings: "Let my prayer be directed as incense in Thy sight."[40] Feast days were instituted for that spiritual joy which is the effect of prayer. Therefore, on such days our prayers should be multiplied.

Secondly, we should offer our body, by mortifying it with fasting:[41] "I beseech you therefore, brethren, by the mercy of God, that you present your bodies a living sacrifice,"[42] and also by praising God: "The sacrifice of praise shall honor Me."[43] And thus on these days our hymns should be more numerous. Thirdly, we should sacrifice our possessions by giving alms: "And do not forget to do good, and to impart; for by such sacrifice God's favor is obtained."[44] And this alms ought to be more than on other days because the Sabbath is a day of common joys: "Send portions to them that have not prepared for themselves, because it is the holy day of the Lord."[45]

Hearing of God's Word.--Our second duty on the Sabbath is to be eager to hear the word of God. This the Jews did daily: "The voices of the prophets which are read every Sabbath."[46] Therefore Christians, whose justice should be more perfect, ought to come together on the Sabbath to hear sermons and participate in the services of the Church! "He that is God, heareth the words of God."[47] We likewise ought to speak with profit to others: "Let no evil speech proceed from your mouth; but that which is good unto sanctification."[48] These two practices are good for the soul of the sinner, because they change his heart for the better: "Are not My words as a fire, saith the Lord, and as a hammer that breaketh the rock in pieces?"[49] The opposite effect is had on those, even the perfect, who neither speak nor hear profitable things: "Evil communications corrupt good manners. Awake, ye just, and sin not."[50] "Thy words have I hidden in my heart."[51] God's word enlightens the ignorant: "Thy word is a lamp to my feet."[52] It inflames the lukewarm: "The word of the Lord inflamed him."[53]


The contemplation of divine things may be exercised on the Sabbath. However, this is for the more perfect.[54] "O taste, and see that the Lord is sweet,"[55] and this is because of the quiet of the soul. For just as the tired body desires rest, so also does the soul. But the soul's proper rest is in God: "Be Thou unto me a God, a protector, and a house of refuge."[56] "There remaineth therefore a day of rest for the people of God. For he that is entered into his rest, the same also hath rested from his works, as God did from His."[57] When I go into my house, I shall repose myself with her" (i.e., Wisdom).[58]

However, before the soul arrives at this rest, three other rests must precede. The first is the rest from the turmoil of sin: "But the wicked are like the raging sea which cannot rest."[59] The second rest is from the passions of the flesh, because "the flesh lusteth against the spirit, and the spirit against the flesh."[60] The third is rest from the occupations of the world: "Martha, Martha, thou art careful and art troubled about many things."[61]


And then after all these things the soul rests peacefully in God: "If thou call the Sabbath delightful . . . then shalt thou be delighted in the Lord,"[63] The Saints gave up everything to possess this rest, "for it is a pearl of great price which a man having found, hid it, and for joy thereof goeth and selleth all that he hath, and buyeth that field."[64] This rest in truth is eternal life and heavenly joy: "This is my rest for ever and ever; here will I dwell, for I have chosen it."[65] And to this rest may the Lord bring us all!

(For "Questions for Discussion" see Chapter 6.)


1. St. Thomas also treats of this Commandment in the "Summa Theologica," I- ll Q. cii, art. 4, 10; "ibid.," II-II, Q. cxxii, art. 4.

2. II Peter, iii. 3-5.

3. Gal., vi. 15.

4. Rom., vi. 4-5.

5. "The Apostles, therefore, resolved to consecrate the first of the seven days of the week to the divine worship, and they called it 'the Lord's Day.' St. John makes mention of 'the Lord's Day' in the Apocalypse (i. 10), and St. Paul commands collections to be made 'on the first day of the week' (I Cor., xvi. 2). . . . From all this we learn that even then the Lord's Day was kept holy in the Church. . . . The Church of God has thought it well to transfer the celebration and observance of the Sabbath to Sunday. On that day light first shone on the world when the Lord arose on that day, and the gate of eternal life was thrown open to us and we were called out of darkness into light. . . . We also learn from the Holy Scriptures that the first day of the week was held sacred for other reasons, viz., on that day the creation began, and on that day the Holy Ghost descended upon the Apostles" ("Roman Catechism." Third Commandment, 7, 18).

6. Ps. xv. 9.

7. "Ibid.," 10.

8. Isa., xiv. 3.

9. "Ibid.," xxxii. 18.

10. Matt., xi. 28-30.

11. Ecclus., li. 35.

12. Wis., ix. 15.

13. Ps. xxxiii. 2.

14. I Thess., v. 17.

15. Ps. cxviii. 164.

16. Isa., lviii. 13-14.

17. Job xxii. 26.

18. This is a reference to the great public spectacles and games.

19. Deut., v. 12-14.

20. I Cor., vi. 11.

21. Jerem., xvii. 22.

22. Levit., xxiii. 25.

23. John, vii. 22-23.

24. Jerem., xviii. 21.

25. Ps. xxxvii. 5.

26. John, viii. 34.

27. Levit., iii. 25.

28. St. Thomas' comparison of sin and servile work follows from the words: "Whosoever committeth sin is the servant of sin," quoted above. This does not mean that commission of sin on the Sabbath changes the species of the sin or gravely increases its malice.

29. This refers to the celebration and special sacrifices offered on the first day of the month. The Lord here is displeased not with the external ritual itself, but with the lack of proper internal dispositions on the part of the Jews.

30. Isa., i. 13.

31. Ecclus., xxxiii. 29.

32. "Ep. ad Rusticum."

33. Ps. xcviii. 4.

34. I Mach, ii. 31-38.

35. Lam., i. 7.

36. I Mach., ii. 41.

37. For the Catholic, of course, the great Sacrifice is that of the Mass. And we are bound to assist at Mass on Sundays and Holydays of obligation unless we are excused for serious reason. "The pastor should not omit to teach the faithful what words and actions they should perform on the festival days. These are: to go to church and there with true piety and devotion assist at the celebration of the Holy Sacrifice of the Mass; and to approach frequently the Sacraments of the Church which were instituted for our salvatlon" ("Roman Catechism," "Third Commandment," 25).

38. I Paral., xxix. 14.

39. Ps. l. 19.

40. Ps. cxl. 2.

41. St. Thomas here refers not to the "fast of affliction" ("jejunium afflictionis") but to the "fast of joy" ("iejunium exultationis"), which is a joyful lifting of the mind to higher things and proceeds from the Holy Ghost who is the spirit of liberty (cfr. "Summa Theol.," III, Q. cxlvii, art. 5).

42 Rom., xii. 1.

43. Ps. xlix. 23.

44. Heb., xiii. 16.

45. II Esdras, viii. 10.

46. Acts, xiii. 27.

47. John, viii. 47.

48. Eph., iv. 29.

49. Jerem., xxiii. 29.

50. I Cor., xv. 33.

51. Ps. cxviii. 11.

52. "Ibid.," 105.

53. Ps. civ. 19.

54. "The spiritual Sabbath consists in a holy and mystical rest wherein, the carnal man (vetus homo, Rom., vi. 4) being buried with Christ, the new man is renewed to life and carefully applies himself to exercise the spirit of Christian piety" ("Roman Calechism," "Third Commandment," 15).

55. Ps. xxxiii. 9.

56. Ps. xxx. 3.

57. Heb., iv. 9-10.

58. Wis., viii. 16.

59. Isa., lvii. 20.

60. Gal., v. 17.

61. Luke, x. 41.

62. "The heavenly Sabbalh, as St. Cyril observes on the words of St. Paul, 'There remaineth therefore a day of rest for the people of God' (Eph., v. 8), is that life in which, living with Christ, we shall experience all joy and all sin will be wiped away ("In Joan.," lib. 4). And in this vision of God the souls of the saints shall obtain every good" ("Roman Catechism," "loc. cit.," 16).

63. Isa., lviii. 13-14.

64. Matt., xiii. 44-46.

65. Ps. cxxxi. 14.

THE FOURTH COMMANDMENT: "Honor thy father and thy mother, that thou mayest be long-lived upon the land which the Lord thy God will give thee."[1]

Perfection for man consists in the love of God and of neighbor. Now, the three Commandments which were written on the first tablet pertain to the love of God; for the love of neighbor there were the seven Commandments on the second tablet. But we must "love, not in word nor in tongue, but in deed and in truth."[2] For a man to love thus, he must do two things, namely, avoid evil and do good. Certain of the Commandments prescribe good acts, while others forbid evil deeds. And we must also know that to avoid evil is in our power; but we are incapable of doing good to everyone. Thus, St. Augustine says that we should love all, but we are not bound to do good to all. But among those to whom we are bound to do good are those in some way united to us. Thus, "if any man have not care of his own and especially of those of his house, he hath denied the faith."[3] Now, amongst all our relatives there are none closer than our father and mother. "We ought to love God first," says St. Ambrose, "then our father and mother." Hence, God has given us the Commandment: "Honor thy father and thy mother."[4]

The Philosopher also gives another reason for this honor to parents, in that we cannot make an equal return to our parents for the great benefits they have granted to us; and, therefore, an offended parent has the right to send his son away, but the son has no such right.[5] Parents, indeed, give their children three things. The first is that they brought them into being: "Honor thy father, and forget not the groanings of thy mother; remember that thou hadst not been born but through them."[6] Secondly, they furnished nourishment and the support necessary for life. For a child comes naked into the world, as Job relates (i. 24), but he is provided for by his parents. The third is instruction: "We have had fathers of our flesh for instructors."[7] "Hast thou children? Instruct them."[8]

Parents, therefore, should give instruction without delay to their children, because "a young man according to his way, even when he is old will not depart from it."[9] And again: "It is good for a man when he hath borne the yoke from his youth."[10] Now, the instruction which Tobias gave his son (Tob., iv) was this: to fear the Lord and to abstain from sin. This is indeed contrary to those parents who approve of the misdeeds of their children. Children, therefore, receive from their parents birth, nourishment, and instruction.


Now, because we owe our birth to our parents, we ought to honor them more than any other superiors, because from such we receive only temporal things: "He that feareth the Lord honoreth his parents, and will serve them as his masters that brought him into the world. Honor thy father in work and word and all patience, that a blessing may come upon thee from him."[11] And in doing this you shall also honor thyself, because "the glory of a man is from honor of his father, and a father without honor is the disgrace of his son."[12]

Again, since we receive nourishment from our parents in our childhood, we must support them in their old age: "Son, support the old age of thy father, and grieve him not in his life. And if his understanding fail, have patience with him; and despise him not when thou art in thy strength. . . . Of what an evil fame is he that forsaketh his father! And he is cursed of God that angereth his mother."[13] For the humiliation of those who act contrary to this, Cassiodorus relates how young storks, when the parents have lost their feathers by approaching old age and are unable to find suitable food, make the parent storks comfortable with their own feathers, and bring back food for their worn-out bodies. Thus, by this affectionate exchange the young ones repay the parents for what they received when they were young."[14]

We must obey our parents, for they have instructed us. "Children, obey your parents in all things."[15] This excepts, of course, those things which are contrary to God. St. Jerome says that the only loyalty in such cases is to be cruel:[16] "If any man hate not his father and mother . . . he cannot be My disciple."[17] This is to say that God is in the truest sense our Father: "Is not He thy Father who hath possessed thee, and hath made thee, and created thee?"[18]


"Honor thy father and thy mother." Among all the Commandments, this one only has the additional words: "that thou mayest be long-lived upon the land." The reason for this is lest it be thought that there is no reward for those who honor their parents, seeing that it is a natural obligation. Hence it must be known that five most desirable rewards are promised those who honor their parents.

Grace and Glory.--The first reward is grace for the present life, and glory in the life to come, which surely are greatly to be desired: "Honor thy father . . . that a blessing may come upon thee from God, and His blessing may remain in the latter end."[19] The very opposite comes upon those who dishonor their parents; indeed, they are cursed in the law by God.[20] It is also written: "He that is unjust in that which is little, is unjust also in that which is greater."[21] But this our natural life is as nothing compared with the life of grace. And so, therefore, if you do not acknowledge the blessing of the natural life which you owe to your parents, then you are unworthy of the life of grace, which is greater, and all the more so for the life of glory, which is the greatest of all blessings.

A Long Life.--The second reward is a long life: "That thou mayest be long- lived upon the land." For "he that honoreth his father shall enjoy a long life."[22] Now, that is a long life which is a full life, and it is not observed in time but in activity, as the Philosopher observes. Life, however, is full inasmuch as it is a life of virtue; so a man who is virtuous and holy enjoys a long life even if in body he dies young: "Being perfect in a short space, he fulfilled a long time; for his soul pleased God."[23] Thus, for example, he is a good merchant who does as much business in one day as another would do in a year. And note well that it sometimes happens that a long life may lead up to a spiritual as well as a bodily death, as was the case with Judas. Therefore, the reward for keeping this Commandment is a long life for the body. But the very opposite, namely, death is the fate of those who dishonor their parents. We receive our life from them; and just as the soldiers owe fealty to the king, and lose their rights in case of any treachery, so also they who dishonor their parents deserve to forfeit their lives: "The eye that mocketh at his father and that despiseth the labor of his mother in bearing him, let the ravens pick it out, and the young eagles eat it."[24] Here "the ravens" signify officials of kings and princes, who in turn are the "young eagles." But if it happens that such are not bodily punished, they nevertheless cannot escape death of the soul. It is not well, therefore, for a father to give too much power to his children: "Give not to son or wife, brother or friend, power over thee while thou livest; and give not thy estate to another, lest thou repent."[25]

The third reward is to have in turn grateful and pleasing children. For a father naturally treasures his children, but the contrary is not always the case: "He that honoreth his father shall have joy in his own children."[26] Again: "With what measure you mete, it shall be measured to you again."[27] The fourth reward is a praiseworthy reputation: "For the glory of a man is from the honor of his father."[28] And again: "Of what an evil fame is he that forsaketh his father?"[29] A fifth reward is riches: "The father's blessing establisheth the houses of his children, but the mother's curse rooteth up the foundation."[30]


"Honor thy father and thy mother." A man is called father not only by reason of generation, but also for other reasons, and to each of these there is due a certain reverence. Thus, the Apostles and the Saints are called fathers because of their doctrine and their exemplification of faith: "For if you have ten thousands instructors in Christ, yet not many fathers. For in Christ Jesus, by the gospel, I have begotten you."[31] And again: "Let us now praise men of renown and our fathers in their generation."[32] However, let us praise them not in word only, but by imitating them; and we do this if nothing is found in us contrary to what we praise in them.

Our superiors in the Church are also called fathers; and they too are to be respected as the ministers of God: "Remember your prelates, . . . whose faith follow, considering the end of their conversation."[33] And again: "He that heareth you, heareth Me; and he that despiseth you, despiseth Me."[34] We honor them by showing them obedience: "Obey your prelates, and be subject to them."[35] And also by paying them tithes: "Honor the Lord with thy substance, and give Him of the first of thy fruits."[36]

Rulers and kings are called fathers: "Father, if the prophet had bid thee do some great thing, surely thou shouldst have done it."[37] We call them fathers because their whole care is the good of their people. And we honor them by being subject to them: "Let every soul be subject to higher powers."[38] We should be subject to them not merely through fear, but through love; and not merely because it is reasonable, but because of the dictates of our conscience. Because "there is no power but from God."[39] And so to all such we must render what we owe them: "Tribute, to whom tribute is due; custom, to whom custom; fear, to whom fear; honor, to whom honor."[40] And again: "My son, fear the Lord and the king."[41]

Our benefactors also are called fathers: "Be merciful to the fatherless as a father."[42] He, too, is like a father [who gives his bond] of whom it is said: "Forget not the kindness of thy surety."[43] On the other hand, the thankless shall receive a punishment such as is written: "The hope of the unthankful shall melt away as the winter's ice."[44] Old men also are called fathers: "Ask thy father, and he will declare to thee; thy elders and they will tell thee."[45] And again: "Rise up before the hoary head, and honor the person of the aged man."[46] "In the company of great men take not upon thee to speak; and when the ancients are present, speak not much."[47] "Hear in silence, and for thy reverence good grace shall come to thee."[48] Now, all these fathers must be honored, because they all resemble to some degree our Father who is in heaven; and of all of them it is said: "He that despiseth you, despiseth Me."[49]

(For "Questions for Discussion" see Chapter 6.)


1. Exod., xx. 12; Deut., v. 16.

2. I John, iii. 18.

3. I Tim., v. 8.

4. St. Thomas also treats of the Fourth Commandment in "Summa Theol.," II- II, QQ. cxxii, ci.

5. Aristotle, "Ethics."

6. Ecclus., vii. 29-30.

7. Heb., xii. 9.

8. Ecclus., vii. 25.

9. Prov. xxii. 6.

10. Lam., iii. 27.

11. Ecclus. iii. 10.

12. "Ibid.," 13.

13. "Ibid.," 14, 15, 18.

14. Epist., lib. II.

15. Col., iii. 20.

16. "Ad Heliod."

17. Luke, xiv. 26.

18. Deut., xxxii. 6.

19. Ecclus., iii. 9-10.

20. Deut., xxvii. 16.

21. Luke, xvi. 10.

22. Ecclus., iii. 7.

23. Wis., iv. 13.

24. Prov., xxx. 17.

25. Ecclus., xxxiii. 20.

26. "Ibid.," iii. 6.

27. Matt., vii. 2.

28. Ecclus., iii. 13.

29. "Ibid.," 18.

30. "Ibid.," 11.

31. I Cor., iv. 15.

32. Ecclus., xliv. 1.

33. Heb., xiii. 7.

34. Luke, x. 16.

35. Heb., xiii. 17.

36. Prov., iii. 9.

37. IV Kings, v. 13.

38. Rom., xiii. 1.

39. "Ibid.," 7

40. "Ibid."

41. Prov., xxiv. 21.

42. Ecclus., iv. 10.

43. "Ibid.," xxix. 19.

44. Wis., xvi. 29.

45. Deut., xxxii. 7.

46. Lev., xix. 32.

47. Ecclus., xxxii. 13.

48. "Ibid.," 9.

49. Luke, x. 16.



In the divine law which tells us we must love God and our neighbor, it is commanded that we not only do good but also avoid evil. The greatest evil that can be done to one's neighbor is to take his life. This is prohibited in the Commandment: "Thou shalt not kill."[1]

Killing of Animals Is Lawful.--In connection with this Commandment there are three errors. Some have said that it is not permitted to kill even brute animals. But this is false, because it is not a sin to use that which is subordinate to the power of man. It is in the natural order that plants be the nourishment of animals, certain animals nourish others, and all for the nourishment of man: "Even the green herbs have I delivered them all to you."[2] The Philosopher says that hunting is like a just war.[3] And St. Paul says: "Whatsoever is sold in the shambles eat; asking no questions for conscience' sake."[4] Therefore, the sense of the Commandment is: "Thou shalt not kill men."

The Execution of Criminals.--Some have held that the killing of man is prohibited altogether. They believe that judges in the civil courts are murderers, who condemn men to death according to the laws. Against this St. Augustine says that God by this Commandment does not take away from Himself the right to kill. Thus, we read: "I will kill and I will make to live."[5] It is, therefore, lawful for a judge to kill according to a mandate from God, since in this God operates, and every law is a command of God: "By Me kings reign, and lawgivers decree just things."[6] And again: "For if thou dost that which is evil, fear; for he beareth not the sword in vain. Because he is God's minister."[7] To Moses also it was said: "Wizards thou shalt not suffer to live."[8] And thus that which is lawful to God is lawful for His ministers when they act by His mandate. It is evident that God who is the Author of laws, has every right to inflict death on account of sin. For "the wages of sin is death."[9] Neither does His minister sin in inflicting that punishment. The sense, therefore, of "Thou shalt not kill" is that one shall not kill by one's own authority.[10]

Suicide is Prohibited.--There are those who held that although this Commandment forbids one to kill another, yet it is lawful to kill oneself. Thus, there are the examples of Samson (Judges, xvi) and Cato and certain virgins who threw themselves into the flames, as St. Augustine relates in "The City of God."[11] But he also explains this in the words: "He who kills himself, certainly kills a man."[12] If it is not lawful to kill except by the authority of God, then it is not lawful to kill oneself except either upon the authority of God or instructed by the Holy Ghost, as was the case of Samson. Therefore, "thou shalt not kill."[13]

Other Meanings of "To Kill."--It ought to be known that to kill a man may happen in several ways. Firstly, by one's own hand: "Your hands are full of blood."[14] This is not only against charity, which tells us to love our neighbor as ourself: "No murderer hath eternal life abiding in himself."[15] But also it is against nature, for "every beast loveth its like."[16] And so it is said: "He that striketh a man with a will to kill him, shall be put to death."[17] He who does this is more cruel than the wolf, of which Aristotle says that one wolf will not eat of the flesh of another wolf.[18]

Secondly, one kills another by word of mouth. This is done by giving counsel to anyone against another by provocation, accusation, or detraction: "The sons of men whose teeth are weapons and arrows, and their tongue a sharp sword."[19] Thirdly, by lending aid, as it is written: "My son, walk not thou with them . . . for their feet run to evil, and they make haste to shed blood."[20] Fourthly, by consent: "They are worthy of death, not only they that do them, but they also that consent to them that do them."[21] Lastly, one kills another by giving a partial consent when the act could be completely prevented: "Deliver them that are led to death;"[22] or, if one can prevent it, yet does not do so through negligence or avarice. Thus, St. Ambrose says: "Give food to him that is dying of hunger; if you do not, you are his murderer."

We have already considered the killing of the body, but some kill the soul also by drawing it away from the life of grace, namely, by inducing it to commit mortal sin: "He was a murderer from the beginning,"[23] that is, in so far as he drew men into sin. Others, however, slay both body and soul. This is possible in two ways: first, by the murder of one with child, whereby the child is killed both in body and soul; and, secondly, by commiting suicide.


Why We Are Forbidden to Be Angry.--In the Gospel of St. Matthew (chapter V) Christ taught that our justice should be greater than the justice of the Old Law. This means that Christians should observe the Commandments of the law more perfectly than the Jews observed them. The reason is that greater effort deserves a better reward: "He who soweth sparingly, shall also reap sparingly."[24] The Old Law promised a temporary and earthly reward: "If you be willing and will hearken to Me, you shall eat the good things of the land."[25] But in the New Law heavenly and eternal things are promised. Therefore, justice, which is the observance of the Commandments, should be more generous because a greater reward is expected.

The Lord mentioned this Commandment in particular among the others when He said: "You have heard that it was said to them of old: Thou shalt not kill. . . . But I say to you that anyone who is angry with his brother, shall be in danger of the judgment."[26] By this is meant the penalty which the law prescribes: "If any man kill his neighbor on set purpose, and by lying in wait for him; thou shalt take him away from My altar, that he may die."[27]

Ways of Avoiding Anger.--Now, there are five ways to avoid being angry. The first is that one be not quickly provoked to anger: "Let every man be swift to hear, but slow to speak and slow to anger."[28] The reason is that anger is a sin, and is punished by God. But is all anger contrary to virtue? There are two opinions about this. The Stoics said that the wise man is free from all passions; even more, they maintained that true virtue consisted in perfect quiet of soul. The Peripatetics, on the other hand, held that the wise man is subject to anger, but in a moderate degree. This is the more accurate opinion. It is proved firstly by authority, in that the Gospel shows us that these passions were attributed to Christ, in whom was the full fountainhead of wisdom. Then, secondly, it is proved from reason. If all the passions were opposed to virtue, then there would be some powers of the soul which would be without good purpose; indeed, they would be positively harmful to man, since they would have no acts in keeping with them. Thus, the irascible and concupiscible powers would be given to man to no purpose. It must, therefore, be concluded that sometimes anger is virtuous, and sometimes it is not.

Three Considerations of Anger.--We see this if we consider anger in three different ways. First, as it exists solely in the judgment of reason, without any perturbation of soul; and this is more properly not anger but judgment. Thus, the Lord punishing the wicked is said to be angry: "I will bear the wrath of the Lord because I have sinned against Him."[29]

Secondly, anger is considered as a passion. This is in the sensitive appetite, and is twofold. Sometimes it is ordered by reason or it is restrained within proper limits by reason, as when one is angry because it is justly fitting to be angry and within proper limits. This is an act of virtue and is called righteous anger. Thus, the Philosopher says that meekness is in no way opposed to anger. This kind of anger then is not a sin.

There is a third kind of anger which overthrows the judgment of reason and is always sinful, sometimes mortally and sometimes venially. And whether it is one or the other will depend on that object to which the anger incites, which is sometimes mortal, sometimes venial. This may be mortal in two ways: either in its genus or by reason of the circumstances. For example, murder would seem to be a mortal sin in its genus, because it is directly opposite to a divine Commandment. Thus, consent to murder is a mortal sin in its genus, because if the act is a mortal sin, then the consent to the act will be also a mortal sin. Sometimes, however, the act itself is mortal in its genus, but, nevertheless, the impulse is not mortal, because it is without consent. This is the same as if one is moved by the impulse of concupiscence to fornication, and yet does not consent; one does not commit a sin. The same holds true of anger. For anger is really the impulse to avenge an injury which one has suffered. Now, if this impulse of the passion is so great that reason is weakened, then it is a mortal sin; if, however, reason is not so perverted by the passion as to give its full consent, then it will be a venial sin. On the other hand, if up to the moment of consent, the reason is not perverted by the passion, and consent is given without this perversion of reason, then there is no mortal sin. "Whosoever is angry with his brother, shall be in danger of the judgment," must be understood of that impulse of passion tending to do injury to the extent that reason is perverted--and this impulse, inasmuch as it is consented to, is a mortal sin.

Why We Should Not Get Angry Easily.--The second reason why we should not be easily provoked to anger is because every man loves liberty and hates restraint. But he who is filled with anger is not master of himself: "Who can bear the violence of one provoked?"[30] And again: "A stone is heavy, and sand weighty, but the anger of a fool is heavier than both."[31]

One should also take care that one does not remain angry over long: "Be ye angry, and sin not."[32] And: "Let not the sun go down upon your anger."[33] The reason for this is given in the Gospel by Our Lord: "Be at agreement with thy adversary betimes whilst thou art in the way with him; lest perhaps the adversary deliver thee to the judge, and the judge deliver thee to the officer, and thou be cast into prison. Amen, I say to thee, thou shalt not go out from hence till thou repay the last farthing."[34]

We should beware lest our anger grow in intensity, having its beginning in the heart, and finally leading on to hatred. For there is this difference between anger and hatred, that anger is sudden, but hatred is long-lived and, thus, is a mortal sin: "Whosoever hateth his brother is a murderer."[35] And the reason is because he kills both himself (by destroying charity) and another. Thus, St. Augustine in his "Rule" says: "Let there be no quarrels among you; or if they do arise, then let them end quickly, lest anger should grow into hatred, the mote becomes a beam, and the soul becomes a murderer."[36] Again: "A passionate man stirreth up strifes."[37] "Cursed be their fury, because it was stubborn, and their wrath, because it was cruel."[38]

We must take care lest our wrath explode in angry words: "A fool immediately showeth his anger."[39] Now, angry words are twofold in effect; either they injure another, or they express one's own pride in oneself. Our Lord has reference to the first when He said: "And whosoever shall say to his brother: 'Thou fool,' shall be in danger of hell fire."[40] And He has reference to the latter in the words: "And he that shall say: 'Raca,' shall be in danger of the council."[41] Moreover: "A mild answer breaketh wrath, but a harsh word stirreth up fury."[42]

Finally, we must beware lest anger provoke us to deeds. In all our dealings we should observe two things, namely, justice and mercy; but anger hinders us in both: "For the anger of a man worketh not the justice of God."[43] For such a one may indeed be willing but his anger prevents him. A certain philosopher once said to a man who had offended him: "I would punish you, were I not angry." "Anger hath no mercy, nor fury when it breaketh forth."[45] And: "In their fury they slew a man."[46]

It is for all this that Christ taught us not only to beware of murder but also of anger. The good physician removes the external symptoms of a malady; and, furthermore, he even removes the very root of the illness, so that there will be no relapse. So also the Lord wishes us to avoid the beginnings of sins; and anger is thus to be avoided because it is the beginning of murder.

(For "Questions for Discussion" see Chapter 6.)


1. St. Thomas also treats of this Commandment in "Summa Theol.," II-II, Q. lxix. art. 2, 3; Q. cxii, art. 6. "The Lord points out (Matt., v. 21) the twofold force of this Commandment. The one is prohihitory and forbids us to kill; the other is mandatory and commands us to cultivate charity, peace, and friendship towards our enemies, to have peace with all men, and finally to suffer all things with patience" ("Roman Catechism," "Fifth Commandment," 2).

2. Gen., ix. 3

3. Aristotle, "Politics," I.

4. I Cor., x. 25.

5. Deut., xxxii. 39.

6. Prov., viii. 15.

7. Rom., xiii. 4.

8. Exod., xxii. 18.

9. Rom. vi. 23.

10. Killing in a just war and killing by accident are among the other exceptions to this Commandment. The soldier is guiltless who in a just war takes the life of an enemy, provided that he is not actuated by motives of ambition or cruelty, but by a pure desire to serve the interests of his country. . . . Again, death caused, not by intent or design, but by accident, is not murder" ("Roman Catechism," "loc. cit.," 5-6).

11. Book I, xxvii.

12. "Ibid."

13.--"It is not lawful to take one-s own life. No man possesses such power over his own life as to be free to put himself to death. We find that the Commandment does not say, 'Thou shalt not kill another,' but simply, 'Thou shalt not kill' " ("Roman Catechism," "loc. cit.," 10).

14. Isa., i. 15.

15. John, iii. 15.

16. Ecclus., xiii. 19.

17. Exod., xxi. 12.

18. "De Animal.," IV.

19. Ps. lvi. 5.

20. Prov., i. 15-16.

21. Rom., i. 32.

22. Prov., xxiv. 11.

23. John, viii. 44.

24. II Cor., ix. 6.

25. Isa., i. 19.

26. Matt., v. 21-22.

27. Exod., xxi. 14. "The Gospel has taught us that it is unlawful even to be angry with anyone. . . . From these words [of Christ, cited above] it clearly follows that he who is angry with his brother is not free from sin, even though he does not display his wrath. So also he who gives indication of his anger sins grievously; and he who treats another with great harshness and hurls insults at him, sins even more grievously. This, however, is to be understood of cases in which no just cause of anger exists. God and His laws permit us to be angry when we correct the faults of those who are subject to us. But even in these cases the anger of a Christian should spring from stern duty and not from the impulse of passion, for we are temples of the Holy Ghost in which Jesus Christ may dwell" ("Roman Catechism," "loc cit.," 12).

28. James, i. 19.

29. Mic., vii. 9.

30. Prov., xxvii. 4.

31. "Ibid.," 3.

32. Ps. iv. 5.

33. Eph., iv. 26.

34. Matt., v. 25, 26.

35. I John, iii. 15.

36. "Epist.," cxi.

37. Prov., xv. 18.

38. Gen., xlix. 7.

39. Prov., xii. 16.

40. Matt., v. 22.

41. "Ibid."

42. Prov., xv. 1.

43. James, i. 20.

44. Prov., xxvii. 4.

45. Gen., xlix. 6.

THE SIXTH COMMANDMENT: "Thou Shalt Not Commit Adultery."

After the prohibition of murder, adultery is forbidden. This is fitting, since husband and wife are as one body. "They shall be," says the Lord, "two in one flesh."[1] Therefore, after an injury inflicted upon a man in his own person, none is so grave as that which is inflicted upon a person with whom one is joined.[2]

Adultery is forbidden both to the wife and the husband. We shall first consider the adultery of the wife, since in this seems to lie the greater sin, for a wife who commits adultery is guilty of three grave sins, which are implied in the following words: "So every woman that leaveth her husband, . . . first, she hath been unfaithful to the law of the Most High; and secondly, she hath offended against her husband; thirdly, she hath fornicated in adultery, and hath gotten her children of another man."

First, therefore, she has sinned by lack of faith, since she is unfaithful to the law wherein God has forbidden adultery. Moreover, she has spurned the ordinance of God: "What therefore God has joined together, let no man put asunder."[4] And also she has sinned against the institution or Sacrament. Because marriage is contracted before the eyes of the Church, and thereupon God is called, as it were, to witness a bond of fidelity which must be kept: "The Lord hath been witness between thee and the wife of thy youth whom thou hast despised."[5] Therefore, she has sinned against the law of God, against a precept of the Church and against a Sacrament of God.

Secondly, she sins by infidelity because she has betrayed her husband: "The wife hath not power of her own body: but the husband."[6] In fact, without the consent of the husband she cannot observe chastity. If adultery is committed, then, an act of treachery is perpetrated in that the wife gives herself to another, just as if a servant gave himself to another master: "She forsaketh the guide of her youth, and hath forgotten the covenant of her God."[7]

Thirdly, the adulteress commits the sin of theft in that she brings forth children from a man not her husband; and this is a most grave theft in that she expends her heredity upon children not her husband's. Let it be noted that such a one should encourage her children to enter religion, or upon such a walk of life that they do not succeed in the property of her husband. Therefore, an adulteress is guilty of sacrilege, treachery and theft.

Husbands, however, do not sin any less than wives, although they sometimes may salve themselves to the contrary. This is clear for three reasons. First, because of the equality which holds between husband and wife, for "the husband also hath not power of his own body, but the wife."[8] Therefore, as far as the rights of matrimony are concerned, one cannot act without the consent of the other. As an indication of this, God did not form woman from the foot or from the head, but from the rib of the man. Now, marriage was at no time a perfect state until the law of Christ came, because the Jew could have many wives, but a wife could not have many husbands; hence, equality did not exist.

The second reason is because strength is a special quality of the man, while the passion proper to the woman is concupiscence: "Ye husbands, likewise dwelling with them according to knowledge, giving honor to the female as to the weaker vessel."[9] Therefore, if you ask from your wife what you do not keep yourself, then you are unfaithful. The third reason is from the authority of the husband. For the husband is head of the wife, and as it is said: "Women may not speak in the church, . . . if they would learn anything, let them ask their husbands at home."[10] The husband is the teacher of his wife, and God, therefore, gave the Commandment to the husband. Now, as regards fulfillment of their duties, a priest who fails is more guilty than a layman, and a bishop more than a priest, because it is especially incumbent upon them to teach others. In like manner, the husband that commits adultery breaks faith by not obeying that which he ought.


Thus, God forbids adultery both to men and women. Now, it must be known that, although some believe that adultery is a sin, yet they do not believe that simple fornication is a mortal sin. Against them stand the words of St. Paul: "For fornicators and adulterers God will judge."[11] And: "Do not err: neither fornicators, . . . nor adulterers, nor the effeminate, nor liers with mankind shall possess the kingdom of God."[12] But one is not excluded from the kingdom of God except by mortal sin; therefore, fornication is a mortal sin.

But one might say that there is no reason why fornication should be a mortal sin, since the body of the wife is not given, as in adultery. I say, however, if the body of the wife is not given, nevertheless, there is given the body of Christ which was given to the husband when he was sanctified in Baptism. If, then, one must not betray his wife, with much more reason must he not be unfaithful to Christ: "Know you not that your bodies are the members of Christ? Shall I then take the members of Christ and make them the members of a harlot? God forbid!"[13] It is heretical to say that fornication is not a mortal sin.

Moreover, it must be known that the Commandment, "Thou shalt not commit adultery," not only forbids adultery but also every form of immodesty and impurity.[14] There are some who say that intercourse between married persons is not devoid of sin. But this is heretical, for the Apostle says: "Let marriage be honorable in all and the bed undefiled."[15] Not only is it devoid of sin, but for those in the state of grace it is meritorious for eternal life. Sometimes, however, it may be a venial sin, sometimes a mortal sin. When it is had with the intention of bringing forth offspring, it is an act of virtue. When it is had with the intent of rendering mutual comfort, it is an act of justice. When it is a cause of exciting lust, although within the limits of marriage, it is a venial sin; and when it goes beyond these limits, so as to intend intercourse with another if possible, it would be a mortal sin.

Adultery and fornication are forbidden for a number of reasons. First of all, because they destroy the soul: "He that is an adulterer, for the folly of his heart shall destroy his own soul."[16] It says: "for the folly of his heart," which is whenever the flesh dominates the spirit. Secondly, they deprive one of life; for one guilty of such should die according to the Law, as we read in Leviticus (xx. 10) and Deuteronomy (xxii. 22). Sometimes the guilty one is not punished now bodily, which is to his disadvantage since punishment of the body may be borne with patience and is conducive to the remission of sins; but nevertheless he shall be punished in the future life. Thirdly, these sins consume his substance, just as happened to the prodigal son in that "he wasted his substance living riotiously."[17] "Give not thy soul to harlots in any point; lest thou destroy thyself and thy inheritance."[18] Fourthly, they defile the offspring: "The children of adulterers shall not come to perfection, and the seed of the unlawful bed shall be rooted out. And if they live long they shall be nothing regarded, and their last old age shall be without honor."[19] And again: "Otherwise your children should be unclean; but now they are holy."[20] Thus, they are never honored in the Church, but if they be clerics their dishonor may go without shame. Fifthly, these sins take away one's honor, and this especially is applicable to women: "Every woman that is a harlot shall be trodden upon as dung in the way."[21] And of the husband it is said: "He gathereth to himself shame and dishonor, and his reproach shall not be blotted out."[22]

St. Gregory says that sins of the flesh are more shameful and less blameful than those of the spirit, and the reason is because they are common to the beasts: "Man when he was in honor did not understand; and he hath been compared to senseless beasts, and made like to them."[23]


1. Gen., ii. 24.

2. "The bond between husband and wife is one of the strictest union, and nothing can be more gratifying to both than to realize that they are objects of mutual and undivided affection. On the other hand, nothing inflicts greater anguish than to feel that the legitimate love which they owe to each other has been transferred elsewhere. This Commandment which prohibits adultery follows properly and in order that which protects human life against the hand of the murderer" ("Roman Catechism," "Sixth Commandment," 1). St. Thomas treats of this Commandment also in the "Summa Theol.," II-II, Q. cxxii, art. 6; Q. cliv.

3. Ecclus., xxiii. 32, 33.

4. Matt., xix. 6.

5. Mal., ii. 14.

6. Cor., vii. 4.

7. Prov., ii. 17-18.

8. I Cor., vii. 4.

9. I Peter, iii. 7.

10. I Cor., xiv. 34-35.

11. Heb., xiii. 4.

12. I Cor., vi. 9.

13. I Cor., vi. 15.

14. "By the prohibition of adultery, every kind of impurity and immodesty by which the body is defiled is also forbidden. Nay more, even every inward thought against chastity is forbidden by this Commandment. . . . You have heard that it was said to them of old: Thou shalt not commit adultery. But I say to you, that whcsoever shall look on a woman to lust after her, hath already committed adultery with her in his heart." ("Roman Catechism," "loc. cit.," 5).

15. Heb., xiii. 4.

16. Prov., vi. 32.

17. Luke, xv. 13.

18. Ecclus., ix. 6.

19. Wis., iii. 16-17.

20. I Cor., vii. 14.

21. Ecclus., ix. 10.

22. Prov., vi. 33.

23. Ps.xlviii. 21. "If the occasions of sin which we have just enumerated [viz., idleness, intemperance in eating and drinking, indulgence of the eyes, immodest dress, immodest conversation and reading] be carefully avoided, almost every excitement to lust will be removed. But the most efficacious means to subdue its violence are frequent use of confession and reception of the Holy Eucharist. Unceasing and devout prayer to God, accompanied by fasting and giving of alms, has the same salutary effect. Chastity is a gilt of God. To those who ask it aright, He does not deny it; nor does He allow us to be tempted beyond our strength" ("Roman Catechism," "loc. cit.," 12).


The Lord specifically forbids injury to our neighbor in the Commandments. Thus, "Thou shalt not kill" forbids us to injure our neighbor in his own person; "Thou shalt not commit adultery" forbids injury to the person to whom one is bound in marriage; and now the Commandment, "Thou shalt not steal," forbids us to injure our neighbor in his goods. This Commandment forbids any worldly goods whatsoever to be taken away wrongfully.[1]

Theft is committed in a number of ways. First, by taking stealthily: "If the goodman of the house knew at what hour the thief would come."[2] This is an act wholly blameworthy because it is a form of treachery. "Confusion . . . is upon the thief."[3]

Secondly, by taking with violence, and this is an even greater injury: "They have violently robbed the fatherless."[4] Among such that do such things are wicked kings and rulers: "Her princes are in the midst of her as roaring lions; her judges are evening wolves, they left nothing for the morning."[5] They act contrary to God's will who wishes a rule according to justice: "By Me kings reign and lawgivers decree just things."[6] Sometimes they do such things stealthily and sometimes with violence: "Thy princes are faithless companions of thieves, they all love bribes, they run after rewards."[7] At times they steal by enacting laws and enforcing them for profit only: "Woe to them that make wicked laws."[8] And St. Augustine says that every wrongful usurpation is theft when he asks: "What are thrones but forms of thievery?"[9]

Thirdly, theft is committed by not paying wages that are due: "The wages of him that hath been hired by thee shall not abide by thee until the morning."[10] This means that a man must pay every one his due, whether he be prince, prelate, or cleric, etc.: "Render therefore to all men their dues. Tribute, to whom tribute is due, custom, to whom custom."[11] Hence, we are bound to give a return to rulers who guard our safety.

The fourth kind of theft is fraud in buying and selling: "Thou shalt not have divers weights in thy bag, a greater and a less."[12] And again: "Do not any unjust thing in judgment, in rule, in weight, or in measure."[13] All this is directed against the keepers of wine-shops who mix water with the wine. Usury is also forbidden: "Who shall dwell in Thy tabernacle, or who shall rest in Thy holy hill? . . . He that hath not put his money out to usury."[14] This is also against money-changers who commit many frauds, and against the sellers of cloth and other goods.

Fifthly, theft is committed by those who buy promotions to positions of temporal or spiritual honor. "The riches which he hath swallowed, he shall vomit up, and God shall draw them out of his belly,"[15] has reference to temporal position. Thus, all tyrants who hold a kingdom or province or land by force are thieves, and are held to restitution. Concerning spiritual dignities: "Amen, amen, I say to you, he that entereth not by the door into the sheepfold but climbeth up another way is a thief and a robber."[16] Therefore, they who commit simony are thieves.


"Thou shalt not steal." This Commandment, as has been said, forbids taking things wrongfully, and we can bring forth many reasons why it is given. The first is because of the gravity of this sin, which is likened to murder: "The bread of the needy is the life of the poor; he that defraudeth them thereof is a man of blood."[18] And again: "He that sheddeth blood and he that defraudeth the laborer of his hire are brothers."[19]

The second reason is the peculiar danger involved in theft, for no sin is so dangerous. After committing other sins a person may quickly repent, for instance, of murder when his anger cools, or of fornication when his passion subsides, and so on for others; but even if one repents of this sin, one does not easily make the necessary satisfaction for it. This is owing to the obligation of restitution and the duty to make up for what loss is incurred by the rightful owner. And all this is above and beyond the obligation to repent for the sin itself: "Woe to him that heapeth together that which is not his own, how long doth he load himself with thick clay!"[20] For thick clay is that from which one cannot easily extricate himself.[21]

The third reason is the uselessness of stolen goods in that they are of no spiritual value: "Treasures of wickedness shall profit nothing."[22] Wealth can indeed be useful for almsgiving and offering of sacrifices, for "the ransom of a man's life are his riches."[23] But it is said of stolen goods: "I am the Lord that love judgment, and hate robbery in a holocaust."[24]. And again: "He that offereth sacrifice of the goods of the poor is as one that sacrificeth the son in the presence of his father."[25]

The fourth reason is that the results of theft are peculiarly harmful to the thief in that they lead to his loss of other goods. It is not unlike the mixture of fire and straw: "Fire shall devour their tabernacles, who love to take bribes."[26] And it ought to be known that a thief may lose not only his own soul, but also the souls of his children, since they are bound to make restitution.

(For "Questions for Discussion" see Chapter 6.)


1. St. Thomas also treats of this Commandment in the "Summa Theol.," II-II, Q. cxxii, Art. 6.

2. Matt., xxiv. 43.

3. Ecclus., v. 17.

4. Job, xxiv. 9.

5. Soph., iii. 3.

6. Prov., viii. 15.

7. Isa., i. 23.

8. "Ibid.," x. 1.

9. "The City of God," IV, 4. "It must be seen that the word 'steal' is understood not only of the taking away of anything from its rightful owner privately and witbout his consent, but also the possession of that which belongs to another, contrary to his will, although not without his knowledge. Otherwise we would say that he who forbids theft does not also forbid robbery, which is accomplished by violence and injustice. . . . So robbery is a greater sin than theft, inasmuch as it not only deprives another of his property, but also offers violence and insult to him. Nor can it be a matter of surprise that the Commandment is expressed in the lighter word, 'steal,' instead of 'rob.' A good reason for this is that theft is more general and of wider extent than robbery" ("Roman Catechism," "Seventh Commandment," 3-4).

10. Lev., xix. 13.

11. Rom., xiii. 7.

12. Deut., xxv. 13.

13. Lev., xix. 35-36.

14. Ps. xiv. 1, 5.

15. Job, xx. 15.

16. John, x. 1.

18. Ecclus., xxxiv. 25.

19. "Ibid.," 27.

20. Hab., ii. 6.

21. "The possession of other men's property is called 'thick clay' by the prophet because it is difficult to emerge and disengage oneself from [ill- gotten goods]. . . . What shall we say of the obligation imposed by God on all of satisfying for the injury done? 'Without restitution,' says St. Augustine, 'the sin is not forgiven' " ("Roman Catechism," "loc. cit.," 8).

22. Prov., x. 2.

23. "Ibid.," xiii. 8.

24. Isa., lxi. 8.

25. Ecclus., xxxiv. 24.

26. Job, xv. 34.

THE EIGHTH COMMANDMENT: "Thou Shalt Not Bear False Witness Against Thy Neighbor."

The Lord has forbidden anyone to injure his neighbor by deed; now he forbids us to injure him by word. "Thou shalt not bear false witness against thy neighbor."[1] This may occur in two ways, either in a court of justice or in ordinary conversation.

In the court of justice it may happen in three ways, according to the three persons who may violate this Commandment in court.[2] The first person is the plaintiff who makes a false accusation: "Thou shalt not be a detractor nor a whisperer among the people."[3] And note well that it is not only wrong to speak falsely, but also to conceal the truth: "If thy brother shall offend against thee, go and rebuke him."[4] The second person is the witness who testifies by lying: "A false witness shall not be unpunished."[5] For this Commandment includes all the preceding ones, inasmuch as the false witness may himself be the murderer or the thief, etc. And such should be punished according to the law. "When after most diligent inquisition, they shall find that the false witness hath told a lie against his brother, they shall render to him as he meant to do to his brother. . . . Thou shalt not pity him, but shalt require life for life, eye for eye, tooth for tooth, hand for hand, foot for foot."[6] And again: "A man that beareth false witness against his neighbor is like a dart and a sword and a sharp arrow."[7] The third person is the judge who sins by giving an unjust sentence: "Thou shalt not . . . judge unjustly. Respect not the person of the poor, nor honor the countenance of the mighty. But judge thy neighbor according to justice."[8]


In ordinary conversation one may violate this Commandment in five ways. The first is by detraction: "Detractors, hateful to God."[9] "Hateful to God" here indicates that nothing is so dear to a man as his good name: "A good name is better than great riches."[10] But detractors take away this good name: "If a serpent bite in silence, he is no better that backbiteth secretly."[11] Therefore, if detractors do not restore this reputation, they cannot be saved.

Secondly, one may break this precept by listening to detractors willingly: "Hedge in thy ears with thorns, hear not a wicked tongue, and make doors and bars to thy mouth."[12] One should not listen deliberately to such things, but ought to turn away, showing a sad and stern countenance: "The north wind driveth away rain as doth a sad countenance a backbiting tongue."[13]

Thirdly, gossipers break this precept when they repeat whatever they hear: "Six things there are which the Lord hateth, and the seventh His soul detesteth . . . him that soweth discord among brethren."[14] Fourthly, those who speak honied words, the flatterers: "The sinner is praised in the desires of his soul, and the unjust man is blessed."[15] And again: "O My people, they that call thee blessed, the same shall deceive thee."[16]


The prohibition of this Commandment includes every form of falsehood: "Be not willing to make any manner of lie; for the custom thereof is no good."[17] There are four reasons for this. The first is that lying likens one to the devil, because a liar is as the son of the devil. Now, we know that a man's speech betrays from what region and country he comes from, thus: "Even thy speech doth discover thee."[18] Even so, some men are of the devil's kind, and are called sons of the devil because they are liars, since the devil is "a liar and the father of lies."[19] Thus, when the devil said, "No, you shall not die the death,"[20] he lied. But, on the contrary, others are the children of God, who is Truth, and they are those who speak the truth.

The second reason is that lying induces the ruin of society. Men live together in society, and this is soon rendered impossible if they do not speak the truth to one another. "Wherefore putting away Iying, speak ye the truth, every man with his neighbor; for we are members one of another."[21]

The third reason is that the liar loses his reputation for the truth. He who is accustomed to telling lies is not believed even when he speaks the truth: "What can be made clean by the unclean? And what truth can come from that which is false?"[22]

The fourth reason is because a liar kills his soul, for "the mouth that belieth killeth the soul."[23] And again: "Thou wilt destroy all that speak a lie."[24] Accordingly, it is clear that lying is a mortal sin; although it must be known that some lies may be venial.

It is a mortal sin, for instance, to lie in matters of faith. This concerns professors, prelates and preachers, and is the gravest of all other kinds of lies: "There shall be among you lying teachers, who shall bring in sects of perdition."[25] Then there are those who lie to wrong their neighbor: "Lie not to one another."[26] These two kinds of lies, therefore, are mortal sins.

There are some who lie for their own advantage, and this in a variety of ways. Sometimes it is out of humility. This may be the case in confession, about which St. Augustine says: "Just as one must avoid concealing what he has committed, so also he must not mention what he has not committed." "Hath God any need of your lie?"[27] And again: "There is one that humbleth himself wickedly, and his interior is full of deceit; and there is one that humbleth himself exceedingly with a great lowness."[28]

There are others who tell lies out of shame, namely, when one tells a falsehood believing that he is telling the truth, and on becoming aware of it he is ashamed to retract: "In no wise speak against the truth, but be ashamed of the lie of thy ignorance."[29] Other some lie for desired results as when they wish to gain or avoid something: "We have placed our hope in lies, and by falsehood we are protected."[30] And again: "He that trusteth in lies feedeth the winds."[31]

Finally, there are some who lie to benefit another, that is, when they wish to free someone from death, or danger, or some other loss. This must be avoided, as St. Augustine tells us: "Accept no person against thy own person, nor against thy soul a lie."[32] But others lie only out of vanity, and this, too, must never be done, lest the habit of such lead us to mortal sin: "For the bewitching of vanity obscureth good things."[33]

(For "Questions for Discussion" see Chapter 6.)


1. St. Thomas also treats of this Commandment in the "Summa Theol.," II-II, Q. cxxii, art. 6.

2. "The Commandment specially prohibits that species of false testimony which is given on oath in a court of justice. The witness swears by the Deity and thus pledges God's holy name for the truth of what he says, and this has very great weight and constitutes the strongest claim for credit. Such testimony, therefore, because it is dangerous, is particularly prohibited. When no legal exceptions can be taken against a sworn witness, and when he cannot be convicted of open dishonesty and malice, even the judge himself cannot reject his testimony. This is especially true since it is commanded by divine authority that 'in the mouth of two or three witnesses every word shall stand' " ("Roman Catechism," "Eighth Commandment," 3).

3. Lev., xix. 16.

4. Matt., xviii. 15.

5. Prov., xix. 5.

6. Deut., xix. 18-21.

7. Prov., xxv. 18.

8. Lev., xix. 15. "This Commandment prohibits deceit, lying, and perjury on the part of witnesses. The same prohibition also applies to plaintiffs, defendants, promoters, representatives, procurators, and advocates; in a word, all who take any part in lawsuits. . . . Finally, God forbids all testimony which may injure others or do them injustice, whether it be a matter of legal evidence or not" ("Roman Catechism," "loc. cit.," 6).

9. Rom., i. 30.

10. Prov., xxii. 1.

11. Eccles., x. 11.

12. Ecclus., xxviii. 28.

13. Prov., xxv. 23. "This Commandment not only forbids false testimony, but also the abominable sin of detraction. This is a moral pestilence which is the poisoned source of many and calamitous evils. . . . That we may see the nature of the sin of detraction more clearly, we must know that reputation is injured not only by calumniating the character. but also by exaggerating the faults of others. He who makes known the secret sin of any man at any time or place unnecessarily, or before persons who have no right to know, is also rightly regarded as a detractor and evil-speaker, if his revelation seriously injures the other's reputation" ("Roman Catechism," "loc. cit.," 9).

14. Prov., vi. 16, 19.

15. Ps. ix. 24

16. Isa., iii. 12. "Flatterers and sycophants are among those who violate this Commandment, for by fawning and insincere praise they gain the hearing and good will of those whose favor. money, and honors they seek" ("Roman Catechism," "loc. cit.," 11).

17. Ecclus, vii. 14.

18. Matt., xxvi. 73.

19. John, viii. 44.

20. Gen. iii. 4.

21. Eph., iv. 25.

22. Ecclus., xxxiv. 4.

23. Wis., i. 11.

24. Ps. v. 7.

25. II Peter, ii. 1.

26. Col., iii. 9.

27. Job, xiii. 7.

28. Ecclus., xix.

29. "Ibid.," iv. 30.

30. Isa., xxviii. 15.

31. Prov., x. 4.

32. Eccles., iv. 26.

33. Wis., iv. 12.

THE NINTH (TENTH) COMMANDMENT:[1] "Thou shalt Not Covet Thy Neighbor's Goods."

"Thou shalt not covet thy neighbor's goods." There is this difference between the divine and the human laws that human law judges only deeds and words, whereas the divine law judges also thoughts. The reason is because human laws are made by men who see things only exteriorly, but the divine law is from God, who sees both external things and the very interior of men. "Thou art the God of my heart."[2] And again: "Man seeth those things that appear, but the Lord beholdeth the heart."[3] Therefore, having considered those Commandments which concern words and deeds, we now treat of the Commandments about thoughts. For with God the intention is taken for the deed, and thus the words, "Thou shalt not covet," mean to include not only the taking by act, but also the intention to take. Therefore, it says: "Thou shalt not even covet thy neighbor's goods." There are a number of reasons for this.

The first reason for the Commandment is that man's desire has no limits, because desire itself is boundless. But he who is wise will aim at some particular end, for no one should have aimless desires: "A covetous man shall not be satisfied with money."[4] But the desires of man are never satisfied, because the heart of man is made for God. Thus, says St. Augustine: "Thou hast made us for Thee, O Lord, and our heart is restless until it rests in Thee."[5] Nothing, therefore, less than God can satisfy the human heart: "Who satisfieth thy desire with good things."[6]

The second reason is that covetousness destroys peace of heart, which is indeed highly delightful. The covetous man is ever solicitous to acquire what he lacks, and to hold that which he has: "The fullness of the rich will not suffer him to sleep."[7] "For where thy treasure is, there is thy heart also."[8] It was for this, says St. Gregory, that Christ compared riches to thorns.[9]

Thirdly, covetousness in a man of wealth renders his riches useless both to himself and to others, because he desires only to hold on to them: "Riches are not comely for a covetous man and a niggard."[10] The fourth reason is that it destroys the equality of justice: "Neither shalt thou take bribes, which even blind the wise, and pervert the words of the just."[11] And again: "He that loveth gold shall not be justified."[12] The fifth reason is that it destroys the love of God and neighbor, for says St. Augustine: "The more one loves, the less one covets," and also the more one covets, the less one loves. "Nor despise thy dear brother for the sake of gold."[13] And just as "No man can serve two masters," so neither can he serve "God and mammon."[14]

Finally, covetousness produces all kinds of wickedness. It is "the root of all evil," says St. Paul, and when this root is implanted in the heart it brings forth murder and theft and all kinds of evil. "They that will become rich, fall into temptation, and into the snare of the devil, and into many unprofitable and hurtful desires which drown men in destruction and perdition. For the desire of money is the root of all evil."[15] And note, furthermore, that covetousness is a mortal sin when one covets one's neighbor's goods without reason; and even if there be a reason, it is a venial sin.[16]


1. St. Thomas places the Tenth Commandment (in the present traditional enumeration) before the Ninth. The Tenth Commandment is wider in extension than the Ninth, which is specific. The "Roman Catechism" ("Ninth and Tenth Commandments" 1) treats both the Ninth and Tenth Commandments together, and remarks that "what is commanded in these two precepts amounts to this, that to observe the preceding Commandments we must be particularly careful not to covet. For he who does not covet, being content with what he has, will not desire what belongs to others, but will rejoice in their prosperity, giving glory to God."

2. Ps. lxxii. 26.

3. I Kings, xvi. 7.

4. Eccles., v. 9.

5. "Confessions," I.

6. Ps. cii. 5.

7. Eccles., v. 11.

8. Matt. vi. 21.

9. Luke viii. 14.

10. Ecclus., xiv. 3.

11. Exod., xxiii. 8.

12. Ecclus., xxxi. 5.

13. "Ibid.," vii. 20.

14. Matt., vi. 24.

15. I Tim., vi. 9, 10.

16. "Another reason for these two Commandments is that they clearly and in definite terms forbid some things not expressly prohibited in the Sixth and Seventh Commandments. The Seventh Commandment, for instance, forbids an unjust desire to take what belongs to another; but the Tenth Commandment further prohibits even to covet it in any way, even though it could be acquired justly and lawfully--if we foresee that by such acquisition our neighbor would suffer some loss. . . . Another reason why this sort of vicious desire is condemned is that it has for its object that which belongs to another, such as a house, maidservant, field, wife, ox, ass, and many other things, all of which the law of God forbids us to covet, simply because they belong to another. The desire for such things, when consented to, is criminal, and is numbered among the most grievous sins. When the mind, yielding to the impulse of evil desires, is pleased with evil or does not resist it, sin is necessarily committed" ("Roman Catechism," loc. cit.," 11).

THE TENTH (NINTH) COMMANDMENT: "Thou Shalt Not Covet Thy Neighbor's Wife."

St. John says in his first Epistle that "all that is in the world is the concupiscence of the flesh, the concupiscence of the eyes, and the pride of life."[1] Now, all that is desirable is included in these three, two of which are forbidden by the precept: "Thou shalt not covet thy neighbor's house."[2] Here "house," signifying height, refers to avarice, for "glory and wealth shall be in his house."[3] This means that he who desires the house, desires honors and riches. And thus after the precept forbidding desire for the house of one's neighbor comes the Commandment prohibiting concupiscence of the flesh: "Thou shalt not covet thy neighbor's wife."[4]

Because of the corruption which resulted from the Fall, none has been free from concupiscence except Christ and the glorious Virgin. And wherever there is concupiscence, there is either venial or mortal sin, provided that it is allowed to dominate the reason.[5] Hence the precept is not, let sin not be; for it is written: "I know that there dwelleth not in me [that is to say, in my flesh] that which is good."[6]

First of all, sin rules in the flesh when, by giving consent to it, concupiscence reigns in the heart. And, therefore, St. Paul adds "so as to obey the lusts thereof" to the words: "Let not sin reign in your mortal body."[7] Accordingly the Lord says: "Whosoever shall look on a woman to lust after her, hath already committed adultery with her in his heart."[8] For with God the intention is taken for the act.

Secondly, sin rules in the flesh when the concupiscence of our heart is expressed in words: "Out of the abundance of the heart the mouth speaketh."[9] And again: "Let no evil speech proceed from your mouth."[10] Therefore, one is not without sin who composes frivolous songs. Even the philosophers so thought, and poets who wrote amatory verses were sent into exile. Lastly, sin rules in the flesh when at the behest of desire the members are made to serve iniquity: "As you have yielded your members to serve uncleanness and iniquity unto iniquity."[11] These, therefore, are the progressive steps of concupiscence.


We must realize that the avoidance of concupiscence demands much labor, for it is based on something within us. It is as hard as trying to capture an enemy in one's own household. However, this desire can be overcome in four ways.

Firstly, by fleeing the external occasions such as, for instance, bad company; and in fact whatever may be an occasion for this sin: "Gaze not upon a maiden lest her beauty be a stumbling-block to thee. . . . Look not around about thee in the ways of the city, nor wander up and down in the streets thereof. Turn away thy face from a woman dressed up, and gaze not about upon another's beauty. For many have perished by the beauty of a woman, and hereby lust is enkindled as a fire."[12] And again: "Can a man hide fire in his bosom, and his garments not burn?"[13] And thus Lot was commanded to flee, "neither stay thou in all the country about."[14]

The second way is by not giving an opening to thoughts which of themselves are the occasion of lustful desires. And this must be done by mortification of the flesh: "I chastise my body, and bring it into subjection."[15] The third way is perseverance in prayer: "Unless the Lord build the house, they labor in vain who build it."[16] And also: "I knew that I could not otherwise be continent, except God gave it."[17] Again: "This kind is not cast out save by prayer and fasting."[18] All this is not unlike to a fight between two persons, one of whom you desire to win, the other to lose. You must sustain the one and withdraw all support from the other. So also between the spirit and the flesh there is a continual combat. Now, if you wish the spirit to win, you must assist it by prayer, and likewise you must resist the flesh by such means as fasting; for by fasting the flesh is weakened.

The fourth way is to keep oneself busy with wholesome occupations: "Idleness hath taught much evil."[19] Again: "This was the iniquity of Sodom thy sister, pride, fullness of bread, and abundance, and the idleness of her."[20] St. Jerome says: "Be always busy in doing something good, so that the devil may find you ever occupied." Now, study of the Scriptures is the best of all occupations, as St. Jerome tells us: "Love to study the Scriptures and you will not love the vices of the flesh."[21]


1. John, ii. 16.

2. The text of Exodus xx. 17, which contains the Ninth and Tenth Commandments, reads as follows: "Thou shalt not covet thy neighbor's house: neither shalt thou desire his wife, nor his servant, nor his hand-maid, nor his ox, nor his ass, nor anything that is his."

3. Ps. cxi. 3.

4. "He [the pastor] will show how these two Commandments are dissimilar; how one covetousness looks only to utility and interest (the tenth), the other to unlawful desire and criminal pleasure (the ninth). If one covets a field or house, he acts out of desire for gain or utility, while he who covets another man's wife yields to a desire for criminal pleasure rather than monetary gain" ("Roman Catechism," "loc. cit., 2).

5. "Concupiscence, the fuel of sin, which originated in sin, is always present in our fallen nature: from it we know that we are born in sin, and, therefore, we suppliantly fly to Him who alone can efface the sordid stains of sin" ("Roman Catechism," "loc. cit.," 5).

6. Rom., vii. 18.

7. "lbid.," vi. 12.

8. Matt., v. 28.

9. Matt., xii. 34.

10. Eph., iv. 29.

11. Rom., vi. 19.

12. Ecclus., ix. 5-9.

13. Prov., vi. 27.

14. Gen., xix. 17.

15. Cor., ix. 27.

16. Ps. cxxvi. 1.

17. Wis., viii. 21.

18. Matt., xvii. 20.

19. Ecclus., xxxiii. 29.

20. Ezech., xvi. 49.

21. "Ad Paulin."


These are the ten precepts to which Our Lord referred when He said: "If thou wilt enter into life, keep the commandments" (Matt., xix. 17). There are two main principles of all the Commandments, namely, love of God and love of neighbor. The man that loves God must necessarily do three things: (1) he must have no other God. And in support of this is the Commandment: "Thou shalt not have strange gods"; (2) he must give God all honor. And so it is commanded: "Thou shalt not take the name of God in vain"; (3) he must freely take his rest in God. Hence: "Remember that thou keep holy the Sabbath day."

But to love God worthily, one must first of all love one's neighbor. And so: "Honor thy father and mother." Then, one must avoid doing harm to one's neighbor in act. "Thou shalt not kill" refers to our neighbor's person; "Thou shalt not commit adultery" refers to the person united in marriage to our neighbor; "Thou shalt not steal" refers to our neighbor's external goods. We must also avoid injury to our neighbor both by word, "Thou shalt not bear false witness," and by thought, "Thou shalt not covet thy neighbor's goods" and "Thou shalt not covet thy neighbor's wife."

(For "Questions for Discussion" see Chapter.)