Article II: On Passion as a Cause of Sin on the Part of the Sensitive Appetite — On Sins of Infirmity

St. Thomas, I-II, q. 77; q. 9, a. 2; De Malo, q. 3, a. 9, 10, 11.

467. On the part of the sensitive appetite the cause of sin is passion, by which man is moved toward a sensible good or is drawn back from a sensible evil, against the good or order of reason. But since passions are certain sicknesses of the soul, which weaken and impede the use of reason and of the will, the sins which proceed from them are commonly called sins of infirmity (Rom. VII, 23; James I, 14).

468. Passion cannot directly draw or move the will, but only indirectly. And indeed:

1. on the part of the subject, by a certain subtraction, by distracting power from the will: for since all the powers proceed from the soul as from one root, it follows a) that the intense exercise of one potency diminishes the force of acting in the others, and b) that man, while he attends vehemently to one thing, is less attentive to other things. Hence the more intensely the sensitive appetite acts, the more remiss the force of the will becomes, or the motion of the will is impeded;¹

¹ The argument concludes for the present state, for powers which need organs, because these, in the present state, lose their powers by exercise; it is not valid for powers which exercise themselves without an organ.

2. by contrariety, on the part of the object or good which reason apprehends, by inclining toward a good contrary to reason: a) for to a man in passion that appears good which does not appear so to him when existing outside passion, just as to one loving or angry there appears a good which does not appear to one who is quiet, and thus passion often tends into an object contrary to reason; moreover b) passion imports a vehement apprehension of the imagination, which reason needs in its exercise, and by which in the case it is inclined especially to consider and approve the object of passion and to judge it good. Hence it happens that the judgment of reason, and consequently the will, often follow passion and act otherwise than if passion were not present;²

² How passion can incline to sinning notwithstanding an opposed universal moral knowledge, St. Thomas indicates, a. 2, ad 4: "He who has knowledge in the universal, on account of passion is impeded lest he be able to take under that universal (proposition), and to arrive at the conclusion; but he takes under another universal, which the inclination of passion suggests, and under it concludes. Hence the Philosopher says, in VII Ethics, that the syllogism of the incontinent man has four propositions, two universal: of which one is of reason, for instance, that no fornication is to be committed, the other is of passion, for instance, that delight is to be pursued. Passion, therefore, binds reason lest it take and conclude under the first; hence while it lasts, it takes and concludes under the second." Cf. De Malo q. 3, a. 9, ad 7.

3. by bodily change, sometimes so transmuting the body that the imagination depends solely on the disposition of the body and is no longer ruled by reason; in this case it totally binds the cognition of reason and impedes its deliberation and use, and consequently sin: thus many, on account of the abundance of love and anger, have been turned into insanity.

469. Inordinate love of self is the cause of every sin. - For to love someone is to will good for him; but by sin someone inordinately wills good for himself; hence sin proceeds from this, that one inordinately loves himself.

But the good which man inordinately seeks for himself is threefold:

a) delectable goods according to touch or the sense of the flesh, which pertain to the conservation of the individual and of the species, and the inordinate appetite for these is the concupiscence of the flesh or natural concupiscence;

b) delectable goods according to the apprehension of the imagination, such as monies, external goods, splendor, pomp, adornment of garments, etc., and the inordinate appetite for these is the concupiscence of the eyes or the cupidity of those things which outwardly appear to the senses and, thus known, please;

c) finally, the inordinate appetite for a difficult or arduous good, and therefore an excellent one, is called pride of life, which is the appetite of excellence.

These three are the cause of all sins (I John II, 16); to these also can be reduced all passions which are the cause of sin: to the first two, all passions of the concupiscible appetite; to the third, all passions of the irascible appetite.

470. Principles. I. Passion which totally binds the use of reason impedes deliberation and liberty and therefore excuses from sin, unless it has been voluntarily contracted in its cause, for example, from drunkenness.

III. Consequent passion, as being voluntary and free, in no way excuses nor diminishes, but either is a sign of the magnitude of the sin, if it proceeds from it by redundancy, or increases it, if it is directly chosen and excited in order to sin more intensely; as was said in the treatise On Human Acts, n. 180.³

³ No concomitant passion is given, because no passion is related to an act of the will without influence.