QUESTION 71: OF VICE AND SIN CONSIDERED IN THEMSELVES
We have in the next place to consider vice and sin: about which six
points have to be considered: (1) Vice and sin considered in themselves;
(2) their distinction; (3) their comparison with one another; (4) the
subject of sin; (5) the cause of sin; (6) the effect of sin.
Under the first head there are six points of inquiry:
(1) Whether vice is contrary to virtue?
(2) Whether vice is contrary to nature?
(3) Which is worse, a vice or a vicious act?
(4) Whether a vicious act is compatible with virtue?
(5) Whether every sin includes action?
(6) Of the definition of sin proposed by Augustine (Contra Faust. xxii):
"Sin is a word, deed, or desire against the eternal law."
Article 1: Whether vice is contrary to virtue?
Objection 1: It would seem that vice is not contrary to virtue. For one thing
has one contrary, as proved in Metaph. x, text. 17. Now sin and malice
are contrary to virtue. Therefore vice is not contrary to it: since vice
applies also to undue disposition of bodily members or of any things
Objection 2: Further, virtue denotes a certain perfection of power. But vice
does not denote anything relative to power. Therefore vice is not
contrary to virtue.
Objection 3: Further, Cicero (De Quaest. Tusc. iv) says that "virtue is the
soul's health." Now sickness or disease, rather than vice, is opposed to
health. Therefore vice is not contrary to virtue.
On the contrary, Augustine says (De Perfect. Justit. ii) that "vice is a
quality in respect of which the soul is evil." But "virtue is a quality
which makes its subject good," as was shown above (Question , Articles ,4).
Therefore vice is contrary to virtue.
I answer that, Two things may be considered in virtue---the essence of
virtue, and that to which virtue is ordained. In the essence of virtue we
may consider something directly, and we may consider something
consequently. Virtue implies "directly" a disposition whereby the subject
is well disposed according to the mode of its nature: wherefore the
Philosopher says (Phys. vii, text. 17) that "virtue is a disposition of a
perfect thing to that which is best; and by perfect I mean that which is
disposed according to its nature." That which virtue implies
"consequently" is that it is a kind of goodness: because the goodness of
a thing consists in its being well disposed according to the mode of its
nature. That to which virtue is directed is a good act, as was shown
above (Question , Article ).
Accordingly three things are found to be contrary to virtue. One of
these is "sin," which is opposed to virtue in respect of that to which
virtue is ordained: since, properly speaking, sin denotes an inordinate
act; even as an act of virtue is an ordinate and due act: in respect of
that which virtue implies consequently, viz. that it is a kind of
goodness, the contrary of virtue is "malice": while in respect of that
which belongs to the essence of virtue directly, its contrary is "vice":
because the vice of a thing seems to consist in its not being disposed in
a way befitting its nature: hence Augustine says (De Lib. Arb. iii):
"Whatever is lacking for a thing's natural perfection may be called a
Reply to Objection 1: These three things are contrary to virtue, but not in the
same respect: for sin is opposed to virtue, according as the latter is
productive of a good work; malice, according as virtue is a kind of
goodness; while vice is opposed to virtue properly as such.
Reply to Objection 2: Virtue implies not only perfection of power, the principle
of action; but also the due disposition of its subject. The reason for
this is because a thing operates according as it is in act: so that a
thing needs to be well disposed if it has to produce a good work. It is
in this respect that vice is contrary to virtue.
Reply to Objection 3: As Cicero says (De Quaest. Tusc. iv), "disease and sickness
are vicious qualities," for in speaking of the body "he calls it" disease
"when the whole body is infected," for instance, with fever or the like;
he calls it sickness "when the disease is attended with weakness"; and
vice "when the parts of the body are not well compacted together." And
although at times there may be disease in the body without sickness, for
instance, when a man has a hidden complaint without being hindered
outwardly from his wonted occupations; "yet, in the soul," as he says,
"these two things are indistinguishable, except in thought." For whenever
a man is ill-disposed inwardly, through some inordinate affection, he is
rendered thereby unfit for fulfilling his duties: since "a tree is known
by its fruit," i.e. man by his works, according to Mt. 12:33. But "vice
of the soul," as Cicero says (De Quaest. Tusc. iv), "is a habit or
affection of the soul discordant and inconsistent with itself through
life": and this is to be found even without disease and sickness, e.g.
when a man sins from weakness or passion. Consequently vice is of wider
extent than sickness or disease; even as virtue extends to more things
than health; for health itself is reckoned a kind of virtue (Phys. vii,
text. 17). Consequently vice is reckoned as contrary to virtue, more
fittingly than sickness or disease.
Article 2: Whether vice is contrary to nature?
Objection 1: It would seem that vice is not contrary to nature. Because vice is contrary to virtue, as stated above (Article ). Now virtue is in us, not by nature but by infusion or habituation, as stated above (Question , Articles ,2,3). Therefore vice is not contrary to nature.
Objection 2: Further, it is impossible to become habituated to that which is
contrary to nature: thus "a stone never becomes habituated to upward
movement" (Ethic. ii, 1). But some men become habituated to vice.
Therefore vice is not contrary to nature.
Objection 3: Further, anything contrary to a nature, is not found in the
greater number of individuals possessed of that nature. Now vice is found
in the greater number of men; for it is written (Mt. 7:13): "Broad is the
way that leadeth to destruction, and many there are who go in thereat."
Therefore vice is not contrary to nature.
Objection 4: Further, sin is compared to vice, as act to habit, as stated
above (Article ). Now sin is defined as "a word, deed, or desire, contrary to
the Law of God," as Augustine shows (Contra Faust. xxii, 27). But the Law
of God is above nature. Therefore we should say that vice is contrary to
the Law, rather than to nature.
On the contrary, Augustine says (De Lib. Arb. iii, 13): "Every vice,
simply because it is a vice, is contrary to nature."
I answer that, As stated above (Article ), vice is contrary to virtue. Now
the virtue of a thing consists in its being well disposed in a manner
befitting its nature, as stated above (Article ). Hence the vice of any thing
consists in its being disposed in a manner not befitting its nature, and
for this reason is that thing "vituperated," which word is derived from
"vice" according to Augustine (De Lib. Arb. iii, 14).
But it must be observed that the nature of a thing is chiefly the form
from which that thing derives its species. Now man derives his species
from his rational soul: and consequently whatever is contrary to the
order of reason is, properly speaking, contrary to the nature of man, as
man; while whatever is in accord with reason, is in accord with the
nature of man, as man. Now "man's good is to be in accord with reason,
and his evil is to be against reason," as Dionysius states (Div. Nom.
iv). Therefore human virtue, which makes a man good, and his work good,
is in accord with man's nature, for as much as it accords with his
reason: while vice is contrary to man's nature, in so far as it is
contrary to the order of reason.
Reply to Objection 1: Although the virtues are not caused by nature as regards
their perfection of being, yet they incline us to that which accords with
reason, i.e. with the order of reason. For Cicero says (De Inv. Rhet. ii)
that "virtue is a habit in accord with reason, like a second nature": and
it is in this sense that virtue is said to be in accord with nature, and
on the other hand that vice is contrary to nature.
Reply to Objection 2: The Philosopher is speaking there of a thing being against
nature, in so far as "being against nature" is contrary to "being from
nature": and not in so far as "being against nature" is contrary to
"being in accord with nature," in which latter sense virtues are said to
be in accord with nature, in as much as they incline us to that which is
suitable to nature.
Reply to Objection 3: There is a twofold nature in man, rational nature, and the
sensitive nature. And since it is through the operation of his senses
that man accomplishes acts of reason, hence there are more who follow the
inclinations of the sensitive nature, than who follow the order of
reason: because more reach the beginning of a business than achieve its
completion. Now the presence of vices and sins in man is owing to the
fact that he follows the inclination of his sensitive nature against the
order of his reason.
Reply to Objection 4: Whatever is irregular in a work of art, is unnatural to the
art which produced that work. Now the eternal law is compared to the
order of human reason, as art to a work of art. Therefore it amounts to
the same that vice and sin are against the order of human reason, and
that they are contrary to the eternal law. Hence Augustine says (De Lib.
Arb. iii, 6) that "every nature, as such, is from God; and is a vicious
nature, in so far as it fails from the Divine art whereby it was made."
Article 3: Whether vice is worse than a vicious act?
Objection 1: It would seem that vice, i.e. a bad habit, is worse than a sin,
i.e. a bad act. For, as the more lasting a good is, the better it is, so
the longer an evil lasts, the worse it is. Now a vicious habit is more
lasting than vicious acts, that pass forthwith. Therefore a vicious habit
is worse than a vicious act.
Objection 2: Further, several evils are more to be shunned than one. But a bad
habit is virtually the cause of many bad acts. Therefore a vicious habit
is worse than a vicious act.
Objection 3: Further, a cause is more potent than its effect. But a habit
produces its actions both as to their goodness and as to their badness.
Therefore a habit is more potent than its act, both in goodness and in
On the contrary, A man is justly punished for a vicious act; but not for
a vicious habit, so long as no act ensues. Therefore a vicious action is
worse than a vicious habit.
I answer that, A habit stands midway between power and act. Now it is
evident that both in good and in evil, act precedes power, as stated in
Metaph. ix, 19. For it is better to do well than to be able to do well,
and in like manner, it is more blameworthy to do evil, than to be able to
do evil: whence it also follows that both in goodness and in badness,
habit stands midway between power and act, so that, to wit, even as a
good or evil habit stands above the corresponding power in goodness or in
badness, so does it stand below the corresponding act. This is also made
clear from the fact that a habit is not called good or bad, save in so
far as it induces to a good or bad act: wherefore a habit is called good
or bad by reason of the goodness or badness of its act: so that an act
surpasses its habit in goodness or badness, since "the cause of a thing
being such, is yet more so."
Reply to Objection 1: Nothing hinders one thing from standing above another
simply, and below it in some respect. Now a thing is deemed above another
simply if it surpasses it in a point which is proper to both; while it is
deemed above it in a certain respect, if it surpasses it in something
which is accidental to both. Now it has been shown from the very nature
of act and habit, that act surpasses habit both in goodness and in
badness. Whereas the fact that habit is more lasting than act, is
accidental to them, and is due to the fact that they are both found in a
nature such that it cannot always be in action, and whose action consists
in a transient movement. Consequently act simply excels in goodness and
badness, but habit excels in a certain respect.
Reply to Objection 2: A habit is several acts, not simply, but in a certain
respect, i.e. virtually. Wherefore this does not prove that habit
precedes act simply, both in goodness and in badness.
Reply to Objection 3: Habit causes act by way of efficient causality: but act
causes habit, by way of final causality, in respect of which we consider
the nature of good and evil. Consequently act surpasses habit both in
goodness and in badness.
Article 4: Whether sin is compatible with virtue?
Objection 1: It would seem that a vicious act, i.e. sin, is incompatible with
virtue. For contraries cannot be together in the same subject. Now sin
is, in some way, contrary to virtue, as stated above (Article ). Therefore
sin is incompatible with virtue.
Objection 2: Further, sin is worse than vice, i.e. evil act than evil habit.
But vice cannot be in the same subject with virtue: neither, therefore,
Objection 3: Further, sin occurs in natural things, even as in voluntary
matters (Phys. ii, text. 82). Now sin never happens in natural things,
except through some corruption of the natural power; thus monsters are
due to corruption of some elemental force in the seed, as stated in Phys.
ii. Therefore no sin occurs in voluntary matters, except through the
corruption of some virtue in the soul: so that sin and virtue cannot be
together in the same subject.
On the contrary, The Philosopher says (Ethic. ii, 2,3) that "virtue is
engendered and corrupted by contrary causes." Now one virtuous act does
not cause a virtue, as stated above (Question , Article ): and, consequently, one
sinful act does not corrupt virtue. Therefore they can be together in the
I answer that, Sin is compared to virtue, as evil act to good habit.
Now the position of a habit in the soul is not the same as that of a form
in a natural thing. For the form of a natural thing produces, of
necessity, an operation befitting itself; wherefore a natural form is
incompatible with the act of a contrary form: thus heat is incompatible
with the act of cooling, and lightness with downward movement (except
perhaps violence be used by some extrinsic mover): whereas the habit that
resides in the soul, does not, of necessity, produce its operation, but
is used by man when he wills. Consequently man, while possessing a habit,
may either fail to use the habit, or produce a contrary act; and so a man
having a virtue may produce an act of sin. And this sinful act, so long
as there is but one, cannot corrupt virtue, if we compare the act to the
virtue itself as a habit: since, just as habit is not engendered by one
act, so neither is it destroyed by one act as stated above (Question , Article , ad 2). But if we compare the sinful act to the cause of the virtues, then
it is possible for some virtues to be destroyed by one sinful act. For
every mortal sin is contrary to charity, which is the root of all the
infused virtues, as virtues; and consequently, charity being banished by
one act of mortal sin, it follows that all the infused virtues are
expelled "as virtues." And I say on account of faith and hope, whose
habits remain unquickened after mortal sin, so that they are no longer
virtues. On the other hand, since venial sin is neither contrary to
charity, nor banishes it, as a consequence, neither does it expel the
other virtues. As to the acquired virtues, they are not destroyed by one
act of any kind of sin.
Accordingly, mortal sin is incompatible with the infused virtues, but is
consistent with acquired virtue: while venial sin is compatible with
virtues, whether infused or acquired.
Reply to Objection 1: Sin is contrary to virtue, not by reason of itself, but by
reason of its act. Hence sin is incompatible with the act, but not with
the habit, of virtue.
Reply to Objection 2: Vice is directly contrary to virtue, even as sin to
virtuous act: and so vice excludes virtue, just as sin excludes acts of
Reply to Objection 3: The natural powers act of necessity, and hence so long as
the power is unimpaired, no sin can be found in the act. On the other
hand, the virtues of the soul do not produce their acts of necessity;
hence the comparison fails.
Article 5: Whether every sin includes an action?
Objection 1: It would seem that every sin includes an action. For as merit is
compared with virtue, even so is sin compared with vice. Now there can be
no merit without an action. Neither, therefore, can there be sin without
Objection 2: Further, Augustine says (De Lib. Arb. iii, 18) [*Cf. De Vera
Relig. xiv.]: So "true is it that every sin is voluntary, that, unless
it be voluntary, it is no sin at all." Now nothing can be voluntary, save
through an act of the will. Therefore every sin implies an act.
Objection 3: Further, if sin could be without act, it would follow that a man
sins as soon as he ceases doing what he ought. Now he who never does
something that he ought to do, ceases continually doing what he ought.
Therefore it would follow that he sins continually; and this is untrue.
Therefore there is no sin without an act.
On the contrary, It is written (James 4:17): "To him . . . who knoweth
to do good, and doth it not, to him it is a sin." Now "not to do" does
not imply an act. Therefore sin can be without act.
I answer that, The reason for urging this question has reference to the
sin of omission, about which there have been various opinions. For some
say that in every sin of omission there is some act, either interior or
exterior---interior, as when a man wills "not to go to church," when he
is bound to go---exterior, as when a man, at the very hour that he is
bound to go to church (or even before), occupies himself in such a way
that he is hindered from going. This seems, in a way, to amount to the
same as the first, for whoever wills one thing that is incompatible with
this other, wills, consequently, to go without this other: unless,
perchance, it does not occur to him, that what he wishes to do, will
hinder him from that which he is bound to do, in which case he might be
deemed guilty of negligence. On the other hand, others say, that a sin of
omission does not necessarily suppose an act: for the mere fact of not
doing what one is bound to do is a sin.
Now each of these opinions has some truth in it. For if in the sin of
omission we look merely at that in which the essence of the sin consists,
the sin of omission will be sometimes with an interior act, as when a man
wills "not to go to church": while sometimes it will be without any act
at all, whether interior or exterior, as when a man, at the time that he
is bound to go to church, does not think of going or not going to church.
If, however, in the sin of omission, we consider also the causes, or
occasions of the omission, then the sin of omission must of necessity
include some act. For there is no sin of omission, unless we omit what we
can do or not do: and that we turn aside so as not to do what we can do
or not do, must needs be due to some cause or occasion, either united
with the omission or preceding it. Now if this cause be not in man's
power, the omission will not be sinful, as when anyone omits going to
church on account of sickness: but if the cause or occasion be subject to
the will, the omission is sinful; and such cause, in so far as it is
voluntary, must needs always include some act, at least the interior act
of the will: which act sometimes bears directly on the omission, as when
a man wills "not to go to church," because it is too much trouble; and in
this case this act, of its very nature, belongs to the omission, because
the volition of any sin whatever, pertains, of itself, to that sin,
since voluntariness is essential to sin. Sometimes, however, the act of
the will bears directly on something else which hinders man from doing
what he ought, whether this something else be united with the omission,
as when a man wills to play at the time he ought to go to church---or,
precede the omission, as when a man wills to sit up late at night, the
result being that he does not go to church in the morning. In this case
the act, interior or exterior, is accidental to the omission, since the
omission follows outside the intention, and that which is outside the
intention is said to be accidental (Phys. ii, text. 49,50). Wherefore it
is evident that then the sin of omission has indeed an act united with,
or preceding the omission, but that this act is accidental to the sin of
Now in judging about things, we must be guided by that which is proper
to them, and not by that which is accidental: and consequently it is
truer to say that a sin can be without any act; else the circumstantial
acts and occasions would be essential to other actual sins.
Reply to Objection 1: More things are required for good than for evil, since
"good results from a whole and entire cause, whereas evil results from
each single defect," as Dionysius states (Div. Nom. iv): so that sin may
arise from a man doing what he ought not, or by his not doing what he
ought; while there can be no merit, unless a man do willingly what he
ought to do: wherefore there can be no merit without act, whereas there
can be sin without act.
Reply to Objection 2: The term "voluntary" is applied not only to that on which
the act of the will is brought to bear, but also to that which we have
the power to do or not to do, as stated in Ethic. iii, 5. Hence even not
to will may be called voluntary, in so far as man has it in his power to
will, and not to will.
Reply to Objection 3: The sin of omission is contrary to an affirmative precept
which binds always, but not for always. Hence, by omitting to act, a man
sins only for the time at which the affirmative precept binds him to act.
Article 6: Whether sin is fittingly defined as a word, deed, or desire contrary to the eternal law?
Objection 1: It would seem that sin is unfittingly defined by saying: "Sin is
a word, deed, or desire, contrary to the eternal law." Because "Word,"
"deed," and "desire" imply an act; whereas not every sin implies an act,
as stated above (Article ). Therefore this definition does not include every
Objection 2: Further, Augustine says (De Duab. Anim. xii): "Sin is the will to retain or obtain what justice forbids." Now will is comprised under desire, in so far as desire denotes any act of the appetite. Therefore it was enough to say: "Sin is a desire contrary to the eternal law," nor was there need to add "word" or "deed."
Objection 3: Further, sin apparently consists properly in aversion from the
end: because good and evil are measured chiefly with regard to the end as
explained above (Question , Article ; Question , Articles ,6; Question , Articles ,3): wherefore
Augustine (De Lib. Arb. i) defines sin in reference to the end, by saying
that "sin is nothing else than to neglect eternal things, and seek after
temporal things": and again he says (Qq. lxxxii, qu. 30) that "all human
wickedness consists in using what we should enjoy, and in enjoying what
we should use." Now the definition is question contains no mention of
aversion from our due end: therefore it is an insufficient definition of
Objection 4: Further, a thing is said to be forbidden, because it is contrary
to the law. Now not all sins are evil through being forbidden, but some
are forbidden because they are evil. Therefore sin in general should not
be defined as being against the law of God.
Objection 5: Further, a sin denotes a bad human act, as was explained above
(Article ). Now man's evil is to be against reason, as Dionysius states (Div.
Nom. iv). Therefore it would have been better to say that sin is against
reason than to say that it is contrary to the eternal law.
On the contrary, the authority of Augustine suffices (Contra Faust.
I answer that, As was shown above (Article ), sin is nothing else than a bad
human act. Now that an act is a human act is due to its being voluntary,
as stated above (Question , Article ), whether it be voluntary, as being elicited
by the will, e.g. to will or to choose, or as being commanded by the
will, e.g. the exterior actions of speech or operation. Again, a human
act is evil through lacking conformity with its due measure: and
conformity of measure in a thing depends on a rule, from which if that
thing depart, it is incommensurate. Now there are two rules of the human
will: one is proximate and homogeneous, viz. the human reason; the other
is the first rule, viz. the eternal law, which is God's reason, so to
speak. Accordingly Augustine (Contra Faust. xxii, 27) includes two things
in the definition of sin; one, pertaining to the substance of a human
act, and which is the matter, so to speak, of sin, when he says "word,"
"deed," or "desire"; the other, pertaining to the nature of evil, and
which is the form, as it were, of sin, when he says, "contrary to the
Reply to Objection 1: Affirmation and negation are reduced to one same genus:
e.g. in Divine things, begotten and unbegotten are reduced to the genus
"relation," as Augustine states (De Trin. v, 6,7): and so "word" and
"deed" denote equally what is said and what is not said, what is done and
what is not done.
Reply to Objection 2: The first cause of sin is in the will, which commands all
voluntary acts, in which alone is sin to be found: and hence it is that
Augustine sometimes defines sin in reference to the will alone. But
since external acts also pertain to the substance of sin, through being
evil of themselves, as stated, it was necessary in defining sin to
include something referring to external action.
Reply to Objection 3: The eternal law first and foremost directs man to his end,
and in consequence, makes man to be well disposed in regard to things
which are directed to the end: hence when he says, "contrary to the
eternal law," he includes aversion from the end and all other forms of
Reply to Objection 4: When it is said that not every sin is evil through being
forbidden, this must be understood of prohibition by positive law. If,
however, the prohibition be referred to the natural law, which is
contained primarily in the eternal law, but secondarily in the natural
code of the human reason, then every sin is evil through being
prohibited: since it is contrary to natural law, precisely because it is
Reply to Objection 5: The theologian considers sin chiefly as an offense against
God; and the moral philosopher, as something contrary to reason. Hence
Augustine defines sin with reference to its being "contrary to the
eternal law," more fittingly than with reference to its being contrary to
reason; the more so, as the eternal law directs us in many things that
surpass human reason, e.g. in matters of faith.