Man requires to be kept by the angels, for in the Providence of God the moveable and variable are governed by the immoveable and invariable. Men, indeed, are variable, and liable to fall into many errors through the application of universal principles to particular cases; they require, ¦ therefore, to be regulated by the invariable, that they may be guided according to knowledge, and follow after truth and goodness. And individual men are guarded by individual angels, because such guardianship forms part of the Divine plan concerning mankind. For Providence acts in a different way towards man, and towards perishable creatures: for man is imperishable, not only as regards the. species, which is common to the race, but in regard of the soul, which is the proper form of the individual. And because Divine Providence takes account chiefly of things which are durable, and of others as subordinated to them, It stands towards each individual man as towards an entire agent or species of perishable things. So, according to Gregory, different Orders of angels have charge of different genera of created things, and probably individual angels of the same Order have charge of different species; hence it is reasonable to suppose that different angels are deputed as guardians to individual men.
These Guardians belong to the lowest Order of angels; for among the angelic offices the care of a single individual is the least, and the more universal charges are distributed in an ascending scale among the higher Orders; for an agent is higher in proportion as it acts more universally. All men have angel guardians; for the journey of life is beset with many dangers, both from within and from without. And since this benefit is common to the human race it is given from the hour of birth; for nature begins with birth; while the gifts of grace which are given to Christians commence with baptism. Nor does a guardian angel ever wholly leave its charge, for Divine Providence never abandons anything wholly. If, therefore, a man appears to be in some measure deserted by his guardian angel, because it does not prevent his being subject to certain tribulations, or falling into sin, this must be attributed to the order of the Divine judgments. Nor if an angel leave a place does its influence thereby cease.
Angels do not, however, grieve over the ills which befall their charges, for grief, properly speaking, implies something contrary to the will; which cannot be with the angels. We may say, indeed, that nothing which happens is contrary to the will of the angels or of the Blessed, because they adhere constantly to the Will of God. Therefore, when there is said to be conflict between the angels, it is not the result of a discord of wills, but of the diversity of their gifts. For all desire to fulfil the Divine Will, which they consult accordingly; and this, called forth by their various merits and offices, is termed a battle among the angels. In such a manner should be explained what is said to Daniel, in the person of the angel Gabriel, about the Prince of the Kingdom of Persia.
- text taken from Compendium of the Summa Theologica of Saint Thomas Aquinas, by Bishop Berardus Bongiovanni