Summa Th. II-II EN Qu.83 a.7
Objection: 1. It would seem that we ought not to pray for others. In praying we ought to conform to the pattern given by our Lord. Now in the Lord's Prayer we make petitions for ourselves, not for others; thus we say: "Give us this day our daily bread," etc. Therefore we should not pray for others.
2. Further, prayer is offered that it may be heard. Now one of the conditions required for prayer that it may be heard is that one pray for oneself, wherefore Augustine in commenting on Jn 16,23, "If you ask the Father anything in My name He will give it you," says (Tract. cii): "Everyone is heard when he prays for himself, not when he prays for all; wherefore He does not say simply 'He will give it,' but 'He will give it you. '" Therefore it would seem that we ought not to pray for others, but only for ourselves.
3. Further, we are forbidden to pray for others, if they are wicked, according to Jr 7,16, "Therefore do not then pray for this people . . . and do not withstand Me, for I will not hear thee." On the other hand we are not bound to pray for the good, since they are heard when they pray for themselves. Therefore it would seem that we ought not to pray for others.
On the contrary It is written (Jc 5,16): "Pray one for another, that you may be saved."
I answer that As stated above (Article ), when we pray we ought to ask for what we ought to desire. Now we ought to desire good things not only for ourselves, but also for others: for this is essential to the love which we owe to our neighbor, as stated above (Question , Articles ,12; Question , Article ; Question , Article ). Therefore charity requires us to pray for others. Hence Chrysostom says (Hom. xiv in Matth.) [*Opus Imperfectum, falsely ascribed to St. John Chrysostom]: "Necessity binds us to pray for ourselves, fraternal charity urges us to pray for others: and the prayer that fraternal charity proffers is sweeter to God than that which is the outcome of necessity."
Reply to Objection: 1. As Cyprian says (De orat. Dom.), "We say 'Our Father' and not 'My Father,' 'Give us' and not 'Give me,' because the Master of unity did not wish us to pray privately, that is for ourselves alone, for He wished each one to pray for all, even as He Himself bore all in one."
2. It is a condition of prayer that one pray for oneself: not as though it were necessary in order that prayer be meritorious, but as being necessary in order that prayer may not fail in its effect of impetration. For it sometimes happens that we pray for another with piety and perseverance, and ask for things relating to his salvation, and yet it is not granted on account of some obstacle on the part of the person we are praying for, according to Jr 15,1, "If Moses and Samuel shall stand before Me, My soul is not towards this people." And yet the prayer will be meritorious for the person who prays thus out of charity, according to Ps 34,13, "My prayer shall be turned into my bosom, i.e. though it profit them not, I am not deprived of my reward," as the gloss expounds it.
3. We ought to pray even for sinners, that they may be converted, and for the just that they may persevere and advance in holiness. Yet those who pray are heard not for all sinners but for some: since they are heard for the predestined, but not for those who are foreknown to death; even as the correction whereby we correct the brethren, has an effect in the predestined but not in the reprobate, according to Qo 7,14, "No man can correct whom God hath despised." Hence it is written (1Jn 5,16): "He that knoweth his brother to sin a sin which is not to death, let him ask, and life shall be given to him, who sinneth not to death." Now just as the benefit of correction must not be refused to any man so long as he lives here below, because we cannot distinguish the predestined from the reprobate, as Augustine says (De Correp. et Grat. xv), so too no man should be denied the help of prayer.We ought also to pray for the just for three reasons: First, because the prayers of a multitude are more easily heard, wherefore a gloss on Rm 15,30, "Help me in your prayers," says: "The Apostle rightly tells the lesser brethren to pray for him, for many lesser ones, if they be united together in one mind, become great, and it is impossible for the prayers of a multitude not to obtain" that which is possible to be obtained by prayer. Secondly, that many may thank God for the graces conferred on the just, which graces conduce to the profit of many, according to the Apostle (2Co 1,11). Thirdly, that the more perfect may not wax proud, seeing that they find that they need the prayers of the less perfect.
Objection: 1. It would seem that we ought not to pray for our enemies. According to Rm 15,4, "what things soever were written, were written for our learning." Now Holy Writ contains many imprecations against enemies; thus it is written (Ps 6,11): "Let all my enemies be ashamed and be . . . troubled, let them be ashamed and be troubled very speedily [*Vulg.: 'Let them be turned back and be ashamed.']." Therefore we too should pray against rather than for our enemies.
2. Further, to be revenged on one's enemies is harmful to them. But holy men seek vengeance of their enemies according to Apoc. 6:10, "How long . . . dost Thou not . . . revenge our blood on them that dwell on earth?" Wherefore they rejoice in being revenged on their enemies, according to Ps 57,11, "The just shall rejoice when he shall see the revenge." Therefore we should not pray for our enemies, but against them.
3. Further, man's deed should not be contrary to his prayer. Now sometimes men lawfully attack their enemies, else all wars would be unlawful, which is opposed to what we have said above (Question , Article ). Therefore we should not pray for our enemies.
On the contrary It is written (Mt 5,44): "Pray for them that persecute and calumniate you."
I answer that To pray for another is an act of charity, as stated above (Article ). Wherefore we are bound to pray for our enemies in the same manner as we are bound to love them. Now it was explained above in the treatise on charity (Question , Articles ,9), how we are bound to love our enemies, namely, that we must love in them their nature, not their sin. and that to love our enemies in general is a matter of precept, while to love them in the individual is not a matter of precept, except in the preparedness of the mind, so that a man must be prepared to love his enemy even in the individual and to help him in a case of necessity, or if his enemy should beg his forgiveness. But to love one's enemies absolutely in the individual, and to assist them, is an act of perfection.In like manner it is a matter of obligation that we should not exclude our enemies from the general prayers which we offer up for others: but it is a matter of perfection, and not of obligation, to pray for them individually, except in certain special cases.
Reply to Objection: 1. The imprecations contained in Holy Writ may be understood in four ways. First, according to the custom of the prophets "to foretell the future under the veil of an imprecation," as Augustine states [*De Serm. Dom. in Monte i, 21]. Secondly, in the sense that certain temporal evils are sometimes inflicted by God on the wicked for their correction. Thirdly, because they are understood to be pronounced, not against the men themselves, but against the kingdom of sin, with the purpose, to wit, of destroying sin by the correction of men. Fourthly, by way of conformity of our will to the Divine justice with regard to the damnation of those who are obstinate in sin.
2. As Augustine states in the same book (De Serm. Dom. in Monte i, 22), "the martyrs' vengeance is the overthrow of the kingdom of sin, because they suffered so much while it reigned": or as he says again (Questions. Vet. et Nov. Test. lxviii), "their prayer for vengeance is expressed not in words but in their minds, even as the blood of Abel cried from the earth." They rejoice in vengeance not for its own sake, but for the sake of Divine justice.
3. It is lawful to attack one's enemies, that they may be restrained from sin: and this is for their own good and for the good of others. Consequently it is even lawful in praying to ask that temporal evils be inflicted on our enemies in order that they may mend their ways. Thus prayer and deed will not be contrary to one another.
Objection: 1. It would seem that the seven petitions of the Lord's Prayer are not fittingly assigned. It is useless to ask for that to be hallowed which is always holy. But the name of God is always holy, according to Lc 1,49, "Holy is His name." Again, His kingdom is everlasting, according to Ps 144,13, "Thy kingdom is a kingdom of all ages." Again, God's will is always fulfilled, according to Isa 46:10, "All My will shall be done." Therefore it is useless to ask for "the name of God to be hallowed," for "His kingdom to come," and for "His will to be done."
2. Further, one must withdraw from evil before attaining good. Therefore it seems unfitting for the petitions relating to the attainment of good to be set forth before those relating to the removal of evil.
3. Further, one asks for a thing that it may be given to one. Now the chief gift of God is the Holy Ghost, and those gifts that we receive through Him. Therefore the petitions seem to be unfittingly assigned, since they do not correspond to the gifts of the Holy Ghost.
4. Further, according to Luke, only five petitions are mentioned in the Lord's Prayer, as appears from the eleventh chapter. Therefore it was superfluous for Matthew to mention seven.
5. Further, it seems useless to seek to win the benevolence of one who forestalls us by his benevolence. Now God forestalls us by His benevolence, since "He first hath loved us" (1Jn 4,19). Therefore it is useless to preface the petitions with the words our "Father Who art in heaven," which seem to indicate a desire to win God's benevolence.
On the contrary The authority of Christ, who composed this prayer, suffices.
I answer that The Lord's Prayer is most perfect, because, as Augustine says (ad Probam Ep. cxxx, 12), "if we pray rightly and fittingly, we can say nothing else but what is contained in this prayer of our Lord." For since prayer interprets our desires, as it were, before God, then alone is it right to ask for something in our prayers when it is right that we should desire it. Now in the Lord's Prayer not only do we ask for all that we may rightly desire, but also in the order wherein we ought to desire them, so that this prayer not only teaches us to ask, but also directs all our affections. Thus it is evident that the first thing to be the object of our desire is the end, and afterwards whatever is directed to the end. Now our end is God towards Whom our affections tend in two ways: first, by our willing the glory of God, secondly, by willing to enjoy His glory. The first belongs to the love whereby we love God in Himself, while the second belongs to the love whereby we love ourselves in God. Wherefore the first petition is expressed thus: "Hallowed be Thy name," and the second thus: "Thy kingdom come," by which we ask to come to the glory of His kingdom.To this same end a thing directs us in two ways: in one way, by its very nature, in another way, accidentally. Of its very nature the good which is useful for an end directs us to that end. Now a thing is useful in two ways to that end which is beatitude: in one way, directly and principally, according to the merit whereby we merit beatitude by obeying God, and in this respect we ask: "Thy will be done on earth as it is in heaven"; in another way instrumentally, and as it were helping us to merit, and in this respect we say: "Give us this day our daily bread," whether we understand this of the sacramental Bread, the daily use of which is profitable to man, and in which all the other sacraments are contained, or of the bread of the body, so that it denotes all sufficiency of food, as Augustine says (ad Probam, Ep. cxxx, 11), since the Eucharist is the chief sacrament, and bread is the chief food: thus in the Gospel of Matthew we read, "supersubstantial," i.e. "principal," as Jerome expounds it.We are directed to beatitude accidentally by the removal of obstacles. Now there are three obstacles to our attainment of beatitude. First, there is sin, which directly excludes a man from the kingdom, according to 1Co 6,9-10, "Neither fornicators, nor idolaters, etc., shall possess the kingdom of God"; and to this refer the words, "Forgive us our trespasses." Secondly, there is temptation which hinders us from keeping God's will, and to this we refer when we say: "And lead us not into temptation," whereby we do not ask not to be tempted, but not to be conquered by temptation, which is to be led into temptation. Thirdly, there is the present penal state which is a kind of obstacle to a sufficiency of life, and to this we refer in the words, "Deliver us from evil."
Reply to Objection: 1. As Augustine says (De Serm. Dom. in Monte ii, 5), when we say, "Hallowed be Thy name, we do not mean that God's name is not holy, but we ask that men may treat it as a holy thing," and this pertains to the diffusion of God's glory among men. When we say, "Thy kingdom come, we do not imply that God is not reigning now," but "we excite in ourselves the desire for that kingdom, that it may come to us, and that we may reign therein," as Augustine says (ad Probam, Ep. cxxx, 11). The words, "Thy will be done rightly signify, 'May Thy commandments be obeyed' on earth as in heaven, i.e. by men as well as by angels" (De Serm. Dom. in Monte ii, 6). Hence these three petitions will be perfectly fulfilled in the life to come; while the other four, according to Augustine (Enchiridion cxv), belong to the needs of the present life
2. Since prayer is the interpreter of desire, the order of the petitions corresponds with the order, not of execution, but of desire or intention, where the end precedes the things that are directed to the end, and attainment of good precedes removal of evil.
3. Augustine (De Serm. Dom. in Monte ii, 11) adapts the seven petitions to the gifts and beatitudes. He says: "If it is fear God whereby blessed are the poor in spirit, let us ask that God's name be hallowed among men with a chaste fear. If it is piety whereby blessed are the meek, let us ask that His kingdom may come, so that we become meek and no longer resist Him. If it is knowledge whereby blessed are they that mourn, let us pray that His will be done, for thus we shall mourn no more. If it is fortitude whereby blessed ere they that hunger, let us pray that our daily bread be given to us. If it is counsel whereby blessed are the merciful, let us forgive the trespasses of others that our own may be forgiven. If it is understanding whereby blessed are the pure in heart, let us pray lest we have a double heart by seeking after worldly things which ere the occasion of our temptations. If it is wisdom whereby blessed are the peacemakers for they shall be called the children of God, let us pray to be delivered from evil: for if we be delivered we shall by that very fact become the free children of God."
4. According to Augustine (Enchiridion cxvi), "Luke included not seven but five petitions in the Lord's Prayer, for by omitting it, he shows that the third petition is a kind of repetition of the two that precede, and thus helps us to understand it"; because, to wit, the will of God tends chiefly to this---that we come to the knowledge of His holiness and to reign together with Him. Again the last petition mentioned by Matthew, "Deliver us from evil," is omitted by Luke, so that each one may know himself to be delivered from evil if he be not led into temptation.
5. Prayer is offered up to God, not that we may bend Him, but that we may excite in ourselves the confidence to ask: which confidence is excited in us chiefly by the consideration of His charity in our regard, whereby he wills our good---wherefore we say: "Our Father"; and of His excellence, whereby He is able to fulfil it---wherefore we say: "Who art in heaven."
Objection: 1. It would seem that prayer is not proper to the rational creature. Asking and receiving apparently belong to the same subject. But receiving is becoming also to uncreated Persons, viz. the Son and Holy Ghost. Therefore it is competent to them to pray: for the Son said (Jn 14,16): "I will ask My [Vulg.: 'the'] Father," and the Apostle says of the Holy Ghost (Rm 8,26): "The Spirit . . . asketh for us."
2. Angels are above rational creatures, since they are intellectual substances. Now prayer is becoming to the angels, wherefore we read in the Ps 96,7: "Adore Him, all you His angels." Therefore prayer is not proper to the rational creature.
3. Further, the same subject is fitted to pray as is fitted to call upon God, since this consists chiefly in prayer. But dumb animals are fitted to call upon God, according to Ps 146,9, "Who giveth to beasts their food and to the young ravens that call upon Him." Therefore prayer is not proper to the rational creatures.
On the contrary Prayer is an act of reason, as stated above (Article ). But the rational creature is so called from his reason. Therefore prayer is proper to the rational creature.
I answer that As stated above (Article ) prayer is an act of reason, and consists in beseeching a superior; just as command is an act of reason, whereby an inferior is directed to something. Accordingly prayer is properly competent to one to whom it is competent to have reason, and a superior whom he may beseech. Now nothing is above the Divine Persons; and dumb animals are devoid of reason. Therefore prayer is unbecoming both the Divine Persons and dumb animals, and it is proper to the rational creature.
Reply to Objection: 1. Receiving belongs to the Divine Persons in respect of their nature, whereas prayer belongs to one who receives through grace. The Son is said to ask or pray in respect of His assumed, i.e. His human, nature and not in respect of His Godhead: and the Holy Ghost is said to ask, because He makes us ask.
2. As stated in the FP, Question , Article , intellect and reason are not distinct powers in us: but they differ as the perfect from the imperfect. Hence intellectual creatures which are the angels are distinct from rational creatures, and sometimes are included under them. In this sense prayer is said to be proper to the rational creature.
3. The young ravens are said to call upon God, on account of the natural desire whereby all things, each in its own way, desire to attain the Divine goodness. Thus too dumb animals are said to obey God, on account of the natural instinct whereby they are moved by God.
Objection: 1. It would seem that the saints in heaven do not pray for us. A man's action is more meritorious for himself than for others. But the saints in heaven do not merit for themselves, neither do they pray for themselves, since they are already established in the term. Neither therefore do they pray for us.
2. Further, the saints conform their will to God perfectly, so that they will only what God wills. Now what God wills is always fulfilled. Therefore it would be useless for the saints to pray for us.
3. Further, just as the saints in heaven are above, so are those in Purgatory, for they can no longer sin. Now those in Purgatory do not pray for us, on the contrary we pray for them. Therefore neither do the saints in heaven pray for us.
4. Further, if the saints in heaven pray for us, the prayers of the higher saints would be more efficacious; and so we ought not to implore the help of the lower saints' prayers but only of those of the higher saints.
5. Further, the soul of Peter is not Peter. If therefore the souls of the saints pray for us, so long as they are separated from their bodies, we ought not to call upon Saint Peter, but on his soul, to pray for us: yet the Church does the contrary. The saints therefore do not pray for us, at least before the resurrection.
On the contrary It is written (2M 2M 15,14): "This is . . . he that prayeth much for the people, and for all the holy city, Jeremias the prophet of God."
I answer that As Jerome says (Cont. Vigilant. 6), the error of Vigilantius consisted in saying that "while we live, we can pray one for another; but that after we are dead, none of our prayers for others can be heard, seeing that not even the martyrs' prayers are granted when they pray for their blood to be avenged." But this is absolutely false, because, since prayers offered for others proceed from charity, as stated above (Articles ,8), the greater the charity of the saints in heaven, the more they pray for wayfarers, since the latter can be helped by prayers: and the more closely they are united to God, the more are their prayers efficacious: for the Divine order is such that lower beings receive an overflow of the excellence of the higher, even as the air receives the brightness of the sun. Wherefore it is said of Christ (He 7,25): "Going to God by His own power . . . to make intercession for us" [*Vulg.: 'He is able to save for ever them that come to God by Him, always living to make intercession for us.']. Hence Jerome says (Cont. Vigilant. 6): "If the apostles and martyrs while yet in the body and having to be solicitous for themselves, can pray for others, how much more now that they have the crown of victory and triumph."
Reply to Objection: 1. The saints in heaven, since they are blessed, have no lack of bliss, save that of the body's glory, and for this they pray. But they pray for us who lack the ultimate perfection of bliss: and their prayers are efficacious in impetrating through their previous merits and through God's acceptance.
2. The saints impetrate what ever God wishes to take place through their prayers: and they pray for that which they deem will be granted through their prayers according to God's will.
3. Those who are in Purgatory though they are above us on account of their impeccability, yet they are below us as to the pains which they suffer: and in this respect they are not in a condition to pray, but rather in a condition that requires us to pray for them.
4. It is God's will that inferior beings should be helped by all those that are above them, wherefore we ought to pray not only to the higher but also to the lower saints; else we should have to implore the mercy of God alone. Nevertheless it happens sometime that prayers addressed to a saint of lower degree are more efficacious, either because he is implored with greater devotion, or because God wishes to make known his sanctity.
5. It is because the saints while living merited to pray for us, that we invoke them under the names by which they were known in this life, and by which they are better known to us: and also in order to indicate our belief in the resurrection, according to the saying of Ex 3,6, "I am the God of Abraham," etc.
Objection: 1. It would seem that prayer ought not to be vocal. As stated above (Article ), prayer is addressed chiefly to God. Now God knows the language of the heart. Therefore it is useless to employ vocal prayer.
2. Further, prayer should lift man's mind to God, as stated above (Article , ad 2). But words, like other sensible objects, prevent man from ascending to God by contemplation. Therefore we should not use words in our prayers.
3. Further, prayer should be offered to God in secret, according to Mt 6,6, "But thou, when thou shalt pray, enter into thy chamber, and having shut the door, pray to thy Father in secret." But prayer loses its secrecy by being expressed vocally. Therefore prayer should not be vocal.
On the contrary It is written (Ps 141,2): "I cried to the Lord with my voice, with my voice I made supplication to the Lord."
I answer that Prayer is twofold, common and individual. Common prayer is that which is offered to God by the ministers of the Church representing the body of the faithful: wherefore such like prayer should come to the knowledge of the whole people for whom it is offered: and this would not be possible unless it were vocal prayer. Therefore it is reasonably ordained that the ministers of the Church should say these prayers even in a loud voice, so that they may come to the knowledge of all.On the other hand individual prayer is that which is offered by any single person, whether he pray for himself or for others; and it is not essential to such a prayer as this that it be vocal. And yet the voice is employed in such like prayers for three reasons. First, in order to excite interior devotion, whereby the mind of the person praying is raised to God, because by means of external signs, whether of words or of deeds, the human mind is moved as regards apprehension, and consequently also as regards the affections. Hence Augustine says (ad Probam. Ep. cxxx, 9) that "by means of words and other signs we arouse ourselves more effectively to an increase of holy desires." Hence then alone should we use words and such like signs when they help to excite the mind internally. But if they distract or in any way impede the mind we should abstain from them; and this happens chiefly to those whose mind is sufficiently prepared for devotion without having recourse to those signs. Wherefore the Psalmist (Ps 26,8) said: "My heart hath said to Thee: 'My face hath sought Thee,'" and we read of Anna (1R 1,13) that "she spoke in her heart." Secondly, the voice is used in praying as though to pay a debt, so that man may serve God with all that he has from God, that is to say, not only with his mind, but also with his body: and this applies to prayer considered especially as satisfactory. Hence it is written (Os 14,3): "Take away all iniquity, and receive the good: and we will render the calves of our lips." Thirdly, we have recourse to vocal prayer, through a certain overflow from the soul into the body, through excess of feeling, according to Ps 15,9, "My heart hath been glad, and my tongue hath rejoiced."
Reply to Objection: 1. Vocal prayer is employed, not in order to tell God something He does not know, but in order to lift up the mind of the person praying or of other persons to God.
2. Words about other matters distract the mind and hinder the devotion of those who pray: but words signifying some object of devotion lift up the mind, especially one that is less devout.
3. As Chrysostom says [*Hom. xiii in the Opus Imperfectum falsely ascribed to St. John Chrysostom], "Our Lord forbids one to pray in presence of others in order that one may be seen by others. Hence when you pray, do nothing strange to draw men's attention, either by shouting so as to be heard by others, or by openly striking the heart, or extending the hands, so as to be seen by many. And yet, "according to Augustine (De Serm. Dom. in Monte ii, 3), "it is not wrong to be seen by men, but to do this or that in order to be seen by men."
Objection: 1. It would seem that attention is a necessary condition of prayer. It is written (Jn 4,24): "God is a spirit, and they that adore Him must adore Him in spirit and in truth." But prayer is not in spirit unless it be attentive. Therefore attention is a necessary condition of prayer.
2. Further, prayer is "the ascent of the mind to God" [*Damascene, De Fide Orth. iii, 24]. But the mind does not ascend to God if the prayer is inattentive. Therefore attention is a necessary condition of prayer.
3. Further, it is a necessary condition of prayer that it should be altogether sinless. Now if a man allows his mind to wander while praying he is not free of sin, for he seems to make light of God; even as if he were to speak to another man without attending to what he was saying. Hence Basil says [*De Constit. Monach. i] that the "Divine assistance is to be implored, not lightly, nor with a mind wandering hither and thither: because he that prays thus not only will not obtain what he asks, nay rather will he provoke God to anger." Therefore it would seem a necessary condition of prayer that it should be attentive.
On the contrary Even holy men sometimes suffer from a wandering of the mind when they pray, according to Ps 39,13, "My heart hath forsaken me."
I answer that This question applies chiefly to vocal prayer. Accordingly we must observe that a thing is necessary in two ways. First, a thing is necessary because thereby the end is better obtained: and thus attention is absolutely necessary for prayer. Secondly, a thing is said to be necessary when without it something cannot obtain its effect. Now the effect of prayer is threefold. The first is an effect which is common to all acts quickened by charity, and this is merit. In order to realize this effect, it is not necessary that prayer should be attentive throughout; because the force of the original intention with which one sets about praying renders the whole prayer meritorious, as is the case with other meritorious acts. The second effect of prayer is proper thereto, and consists in impetration: and again the original intention, to which God looks chiefly, suffices to obtain this effect. But if the original intention is lacking, prayer lacks both merit and impetration: because, as Gregory [*Hugh St. Victor, Expos. in Reg. S. Aug. iii] says, "God hears not the prayer of those who pay no attention to their prayer." The third effect of prayer is that which it produces at once; this is the spiritual refreshment of the mind, and for this effect attention is a necessary condition: wherefore it is written (1Co 14,14): "If I pray in a tongue . . . my understanding is without fruit."It must be observed, however, that there are three kinds of attention that can be brought to vocal prayer: one which attends to the words, lest we say them wrong, another which attends to the sense of the words, and a third, which attends to the end of prayer, namely, God, and to the thing we are praying for. That last kind of attention is most necessary, and even idiots are capable of it. Moreover this attention, whereby the mind is fixed on God, is sometimes so strong that the mind forgets all other things, as Hugh of St. Victor states [*De Modo Orandi ii].
Reply to Objection: 1. To pray in spirit and in truth is to set about praying through the instigation of the Spirit, even though afterwards the mind wander through weakness.
2. The human mind is unable to remain aloft for long on account of the weakness of nature, because human weakness weighs down the soul to the level of inferior things: and hence it is that when, while praying, the mind ascends to God by contemplation, of a sudden it wanders off through weakness.
3. Purposely to allow one's mind to wander in prayer is sinful and hinders the prayer from having fruit. It is against this that Augustine says in his Rule (Ep. ccxi): "When you pray God with psalms and hymns, let your mind attend to that which your lips pronounce." But to wander in mind unintentionally does not deprive prayer of its fruit. Hence Basil says (De Constit. Monach. i): "If you are so truly weakened by sin that you are unable to pray attentively, strive as much as you can to curb yourself, and God will pardon you, seeing that you are unable to stand in His presence in a becoming manner, not through negligence but through frailty."
Objection: 1. It would seem that prayer should not be continual. It is written (Mt 6,7): "When you are praying, speak not much." Now one who prays a long time needs to speak much, especially if his be vocal prayer. Therefore prayer should not last a long time.
2. Further, prayer expresses the desire. Now a desire is all the holier according as it is centered on one thing, according to Ps 26,4, "One thing I have asked of the Lord, this will I seek after." Therefore the shorter prayer is, the more is it acceptable to God.
3. Further, it seems to be wrong to transgress the limits fixed by God, especially in matters concerning Divine worship, according to Ex 19,21: "Charge the people, lest they should have a mind to pass the limits to see the Lord, and a very great multitude of them should perish." But God has fixed for us the limits of prayer by instituting the Lord's Prayer (Mt 6). Therefore it is not right to prolong our prayer beyond its limits.
On the contrary On the contrary, It would seem that we ought to pray continually. For our Lord said (Lc 18,1): "We ought always to pray, and not to faint": and it is written (1Th 5,17): "Pray without ceasing."
I answer that We may speak about prayer in two ways: first, by considering it in itself; secondly, by considering it in its cause. The not cause of prayer is the desire of charity, from which prayer ought to arise: and this desire ought to be in us continually, either actually or virtually, for the virtue of this desire remains in whatever we do out of charity; and we ought to "do all things to the glory of God" (1Co 10,31). From this point of view prayer ought to be continual: wherefore Augustine says (ad Probam, Ep. cxxx, 9): "Faith, hope and charity are by themselves a prayer of continual longing." But prayer, considered in itself, cannot be continual, because we have to be busy about other works, and, as Augustine says (ad Probam. Ep. cxxx, 9), "we pray to God with our lips at certain intervals and seasons, in order to admonish ourselves by means of such like signs, to take note of the amount of our progress in that desire, and to arouse ourselves more eagerly to an increase thereof." Now the quantity of a thing should be commensurate with its end, for instance the quantity of the dose should be commensurate with health. And so it is becoming that prayer should last long enough to arouse the fervor of the interior desire: and when it exceeds this measure, so that it cannot be continued any longer without causing weariness, it should be discontinued. Wherefore Augustine says (ad Probam. Ep. cxxx): "It is said that the brethren in Egypt make frequent but very short prayers, rapid ejaculations, as it were, lest that vigilant and erect attention which is so necessary in prayer slacken and languish, through the strain being prolonged. By so doing they make it sufficiently clear not only that this attention must not be forced if we are unable to keep it up, but also that if we are able to continue, it should not be broken off too soon." And just as we must judge of this in private prayers by considering the attention of the person praying, so too, in public prayers we must judge of it by considering the devotion of the people.
Reply to Objection: 1. As Augustine says (ad Probam. Ep. cxxx), "to pray with many words is not the same as to pray long; to speak long is one thing, to be devout long is another. For it is written that our Lord passed the whole night in prayer, and that He 'prayed the longer' in order to set us an example." Further on he says: "When praying say little, yet pray much so long as your attention is fervent. For to say much in prayer is to discuss your need in too many words: whereas to pray much is to knock at the door of Him we pray, by the continuous and devout clamor of the heart. Indeed this business is frequently done with groans rather than with words, with tears rather than with speech."
2. Length of prayer consists, not in praying for many things, but in the affections persisting in the desire of one thing.
3. Our Lord instituted this prayer, not that we might use no other words when we pray, but that in our prayers we might have none but these things in view, no matter how we express them or think of them.
4. One may pray continually, either through having a continual desire, as stated above; or through praying at certain fixed times, though interruptedly; or by reason of the effect, whether in the person who prays---because he remains more devout even after praying, or in some other person---as when by his kindness a man incites another to pray for him, even after he himself has ceased praying.
Summa Th. II-II EN Qu.83 a.7