§ II. On Internal Causes

The general internal cause of every sin is disordered love of self, according to Augustine's saying: "Two loves have therefore made two cities: namely, love of self even to contempt of God made the earthly city, but love of God even to contempt of self made the heavenly city."¹ This disordered love manifests itself by a threefold concupiscence: namely, the concupiscence of the flesh, by which man is inclined to the pleasure of taste and touch; the concupiscence of the eyes, by which he is inclined to riches and temporal goods; the pride of life, by which he is enticed to the undue honors of his estimated excellence (St. Thomas, I-II, q. 77, aa. 4 and 5).

Specifically and practically, culpable ignorance, concupiscence, slothfulness, and malice are assigned as internal causes of sin.

¹ De civitate Dei, bk. 14, c. 28.

I. Culpable ignorance; which can be a cause of sin to the extent that man, if he had expelled the ignorance, would have abstained from the depraved act. To this cause also belongs defect of consideration, which is a certain actual culpable ignorance, concerning which the prophet Jeremiah says: "With desolation the whole land is made desolate, because there is no one who reflects in the heart."¹

¹ Jer. 12:11.

II. Concupiscence - by which here is understood every passion or motion of the sensitive appetite - is the cause of sin according to these words of St. James: "Each one is tempted by his own concupiscence, drawn away and enticed. Then concupiscence, when it has conceived, brings forth sin."¹ Sins which are perpetrated from concupiscence are called sins of weakness (St. Thomas, I-II, q. 77, a. 3). Such commonly are self-pollutions, morose delectations, drunkenness, hatred of neighbor, blasphemies, which nevertheless by others are also uttered from malice (St. Alphonsus, VI, 463).

¹ James 1:14.

III. Slothfulness, i.e., lack of zeal and affection toward those things which concern the salvation of the soul. From slothfulness commonly arise neglects of Mass, of the abstinence to be observed, etc.

IV. Malice, i.e., the depravity of the will by which someone sins even if vehement passion does not incite him to sin. Among sins from malice are counted hatred of God, hindering the good which priests and other good men promote; likewise, commonly, sins against the Holy Spirit, and those which are said to cry to heaven.

Finally, note that one actual sin is sometimes the cause of other sins: first, indirectly, when God, in order to punish sin, permits that someone fall into sin, whether light or grave. Of this both the doctrine of the Saints and especially St. Paul in the Epistle to the Romans is witness: "On account of this," i.e., on account of the sin of neglecting the glorification of God, "God handed them," that is, the ancient philosophers, "over to passions of shame."¹ In another way, directly, sin is the cause of sin, namely by force both of an increased inclination toward sins of the same species and of the connection which exists among depraved acts of diverse species. Thus - the examples are legion - thus Cain first sinned by envy against his brother, then by hatred, then by homicide, and finally despaired of the mercy of God... Thus also Judas first sinned by avarice, then handed over Jesus Christ, and finally brought death upon himself (St. Alphonsus, Sermoni compendiati, Twenty-Second Sunday after Pentecost). To this, moreover, those sins especially are to be referred which are called capital, because from them as from heads other sins naturally arise. Of these there will be a specific discussion later.

¹ Rom. 1:26.