law. Therefore man is not guarded by an
angel.

Obj. 2: Further, a strong guard makes a weaker one superfluous. But
men are guarded by God, according to Ps. 120:4: "He shall neither
slumber nor sleep, that keepeth Israel." Therefore man does not need
to be guarded by an angel.

Obj. 3: Further, the loss of the guarded redounds to the negligence
of the guardian; hence it was said to a certain one: "Keep this man;
and if he shall slip away, thy life shall be for his life" (3 Kings
20:39). Now many perish daily through falling into sin; whom the
angels could help by visible appearance, or by miracles, or in some
such-like way. The angels would therefore be negligent if men are
given to their guardianship. But that is clearly false. Therefore
the angels are not the guardians of men.

_On the contrary,_ It is written (Ps. 90:11): "He hath given His
angels charge over thee, to keep thee in all thy ways."

_I answer that,_ According to the plan of Divine Providence, we find
that in all things the movable and variable are moved and regulated
by the immovable and invariable; as all corporeal things by immovable
spiritual substances, and the inferior bodies by the superior which
are invariable in substance. We ourselves also are regulated as
regards conclusions, about which we may have various opinions, by the
principles which we hold in an invariable manner. It is moreover
manifest that as regards things to be done human knowledge and
affection can vary and fail from good in many ways; and so it was
necessary that angels should be deputed for the guardianship of men,
in order to regulate them and move them to good.

Reply Obj. 1: By free-will man can avoid evil to a certain degree,
but not in any sufficient degree; forasmuch as he is weak in
affection towards good on account of the manifold passions of the
soul. Likewise universal natural knowledge of the law, which by
nature belongs to man, to a certain degree directs man to good, but
not in a sufficient degree; because in the application of the
universal principles of law to particular actions man happens to be
deficient in many ways. Hence it is written (Wis. 9:14): "The
thoughts of mortal men are fearful, and our counsels uncertain."
Thus man needs to be guarded by the angels.

Reply Obj. 2: Two things are required for a good action; first, that
the affection be inclined to good, which is effected in us by the
habit of mortal virtue. Secondly, that reason should dis