there can be sin in the will of every creature;
considering the condition of its nature.

Reply Obj. 1: In the angels there is no potentiality to natural
existence. Yet there is potentiality in their intellective part, as
regards their being inclined to this or the other object. In this
respect there can be evil in them.

Reply Obj. 2: The heavenly bodies have none but a natural operation.
Therefore as there can be no evil of corruption in their nature; so
neither can there be evil of disorder in their natural action. But
besides their natural action there is the action of free-will in the
angels, by reason of which evil may be in them.

Reply Obj. 3: It is natural for the angel to turn to God by the
movement of love, according as God is the principle of his natural
being. But for him to turn to God as the object of supernatural
beatitude, comes of infused love, from which he could be turned away
by sinning.

Reply Obj. 4: Mortal sin occurs in two ways in the act of free-will.
First, when something evil is chosen; as man sins by choosing
adultery, which is evil of itself. Such sin always comes of ignorance
or error; otherwise what is evil would never be chosen as good. The
adulterer errs in the particular, choosing this delight of an
inordinate act as something good to be performed now, from the
inclination of passion or of habit; even though he does not err in
his universal judgment, but retains a right opinion in this respect.
In this way there can be no sin in the angel; because there are no
passions in the angels to fetter reason or intellect, as is manifest
from what has been said above (Q. 59, A. 4); nor, again, could any
habit inclining to sin precede their first sin. In another way sin
comes of free-will by choosing something good in itself, but not
according to proper measure or rule; so that the defect which induces
sin is only on the part of the choice which is not properly
regulated, but not on the part of the thing chosen; as if one were to
pray, without heeding the order established by the Church. Such a sin
does not presuppose ignorance, but merely absence of consideration of
the things which ought to be considered. In this way the angel
sinned, by seeking his own good, from his own free-will,
insubordinately to the rule of the Divine will.
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SECOND ARTICLE [I, Q. 63, Art. 2]

Whether Only the Sin of Pride and Envy Can Exist in an Angel?

Objection 1: It would seem that t