Reply to Objection 1: A guardian may be assigned to a man for two reasons: first, inasmuch as a man is an individual, and thus to one man one guardian is due; and sometimes several are appointed to guard one. Secondly, inasmuch as a man is part of a community, and thus one man is appointed as guardian of a whole community; to whom it belongs to provide what concerns one man in his relation to the whole community, such as external works, which are sources of strength or weakness to others. But angel guardians are given to men also as regards invisible and occult things, concerning the salvation of each one in his own regard. Hence individual angels are appointed to guard individual men.
Reply to Objection 2: As above stated (Q[112], A[3], ad 4), all the angels of the first hierarchy are, as to some things, enlightened by God directly; but as to other things, only the superior are directly enlightened by God, and these reveal them to the inferior. And the same also applies to the inferior orders: for a lower angel is enlightened in some respects by one of the highest, and in other respects by the one immediately above him. Thus it is possible that some one angel enlightens a man immediately, and yet has other angels beneath him whom he enlightens.
Reply to Objection 3: Although men are equal in nature, still inequality exists among them, according as Divine Providence orders some to the greater, and others to the lesser things, according to Sir. 33:11 , 12 : "With much knowledge the Lord hath divided them, and diversified their ways: some of them hath He blessed and exalted, and some of them hath He cursed and brought low." Thus it is a greater office to guard one man than another.
Whether to guard men belongs only to the lowest order of angels?
Objection 1: It would seem that the guardianship of men does not belong only to the lowest order of the angels. For Chrysostom says that the text ( Mat. 18:10 ), "Their angels in heaven," etc. is to be understood not of any angels but of the highest. Therefore the superior angels guard men.
Objection 2: Further, the Apostle says that angels "are sent to minister for them who shall receive the inheritance of salvation" ( Heb. 1:14 ); and thus it seems that the mission of the angels is directed to the guardianship of men. But five orders are sent in external ministry (Q[112], A[4]). Therefore all the angels of the five orders are deputed to the guardianship of men.
Objection 3: Further, for the guardianship of men it seems especially necessary to coerce the demons, which belongs most of all to the Powers, according to Gregory (Hom. xxxiv in Evang.); and to work miracles, which belongs to the Virtues. Therefore these orders are also deputed to the work of guardianship, and not only the lowest order.
On the contrary, In the Psalm (90) the guardianship of men is attributed to the angels; who belong to the lowest order, according to Dionysius (Coel. Hier. v, ix).
I answer that, As above stated (A[2]), man is guarded in two ways; in one way by particular guardianship, according as to each man an angel is appointed to guard him; and such guardianship belongs to the lowest order of the angels, whose place it is, according to Gregory, to announce the "lesser things"; for it seems to be the least of the angelic offices to procure what concerns the salvation of only one man. The other kind of guardianship is universal, multiplied according to the different orders. For the more universal an agent is, the higher it is. Thus the guardianship of the human race belongs to the order of "Principalities," or perhaps to the "Archangels," whom we call the angel princes. Hence, Michael, whom we call an archangel, is also styled "one of the princes" ( Dan. 10:13 ). Moreover all corporeal creatures are guarded by the "Virtues"; and likewise the demons by the "Powers," and the good spirits by the "Principalities," according to Gregory's opinion (Hom. xxxiv in Ev.).
Reply to Objection 1: Chrysostom can be taken to mean the highest in the lowest order of angels; for, as Dionysius says (Coel. Hier. x) in each order there are first, middle, and last. It is, however, probable that the greater angels are deputed to keep those chosen by God for the higher degree of glory.
Reply to Objection 2: Not all the angels who are sent have guardianship of individual men; but some orders have a universal guardianship, greater or less, as above explained.
Reply to Objection 3: Even inferior angels exercise the office of the superior, as they share in their gifts, and they are executors of the superiors' power; and in this way all the angels of the lowest order can coerce the demons, and work miracles.
Whether angels are appointed to the guardianship of all men?
Objection 1: It would seem that angels are not appointed to the guardianship of all men. For it is written of Christ ( Phil. 2:7 ) that "He was made in the likeness of men, and in habit found as a man." If therefore angels are appointed to the guardianship of all men, Christ also would have had an angel guardian. But this is unseemly, for Christ is greater than all the angels. Therefore angels are not appointed to the guardianship of all men.
Objection 2: Further, Adam was the first of all men. But it was not fitting that he should have an angel guardian, at least in the state of innocence: for then he was not beset by any dangers. Therefore angels are not appointed to the guardianship of all men.
Objection 3: Further, angels are appointed to the guardianship of men, that they may take them by the hand and guide them to eternal life, encourage them to good works, and protect them against the assaults of the demons. But men who are foreknown to damnation, never attain to eternal life. Infidels, also, though at times they perform good works, do not perform them well, for they have not a right intention: for "faith directs the intention" as Augustine says (Enarr. ii in Ps. 31 ). Moreover, the coming of Antichrist will be "according to the working of Satan," as it is written ( 2 Thess. 2:9 ). Therefore angels are not deputed to the guardianship of all men.
On the contrary, is the authority of Jerome quoted above (A[2]), for he says that "each soul has an angel appointed to guard it."
I answer that, Man while in this state of life, is, as it were, on a road by which he should journey towards heaven. On this road man is threatened by many dangers both from within and from without, according to Ps. 159:4: "In this way wherein I walked, they have hidden a snare for me." And therefore as guardians are appointed for men who have to pass by an unsafe road, so an angel guardian is assigned to each man as long as he is a wayfarer. When, however, he arrives at the end of life he no longer has a guardian angel; but in the kingdom he will have an angel to reign with him, in hell a demon to punish him.
Reply to Objection 1: Christ as man was guided immediately by the Word of God: wherefore He needed not be guarded by an angel. Again as regards His soul, He was a comprehensor, although in regard to His passible body, He was a wayfarer. In this latter respect it was right that He should have not a guardian angel as superior to Him, but a ministering angel as inferior to Him. Whence it is written ( Mat. 4:11 ) that "angels came and ministered to Him."
Reply to Objection 2: In the state of innocence man was not threatened by any peril from within: because within him all was well ordered, as we have said above (Q[95], AA[1],3). But peril threatened from without on account of the snares of the demons; as was proved by the event. For this reason he needed a guardian angel.
Reply to Objection 3: Just as the foreknown, the infidels, and even Anti-christ, are not deprived of the interior help of natural reason; so neither are they deprived of that exterior help granted by God to the whole human race---namely the guardianship of the angels. And although the help which they receive therefrom does not result in their deserving eternal life by good works, it does nevertheless conduce to their being protected from certain evils which would hurt both themselves and others. For even the demons are held off by the good angels, lest they hurt as much as they would. In like manner Antichrist will not do as much harm as he would wish.
Whether an angel is appointed to guard a man from his birth?
Objection 1: It would seem that an angel is not appointed to guard a man from his birth. For angels are "sent to minister for them who shall receive the inheritance of salvation," as the Apostle says ( Heb. 1:14 ). But men begin to receive the inheritance of salvation, when they are baptized. Therefore an angel is appointed to guard a man from the time of his baptism, not of his birth.
Objection 2: Further, men are guarded by angels in as far as angels enlighten and instruct them. But children are not capable of instruction as soon as they are born, for they have not the use of reason. Therefore angels are not appointed to guard children as soon as they are born.
Objection 3: Further, a child has a rational soul for some time before birth, just as well as after. But it does not appear that an angel is appointed to guard a child before its birth, for they are not then admitted to the sacraments of the Church. Therefore angels are not appointed to guard men from the moment of their birth.