Sin by New Advent Encyclopedia

The subject is treated under these heads:

  • Nature of sin
  • Division
  • Mortal sin
  • Venial sin
  • Permission and remedies
  • The sense of sin

Nature of sin

Since sin is a moral evil, it is necessary in the first place to determine what is meant by evil, and in particular by moralevil. Evil is defined by St. Thomas (De malo, 2:2) as a privation of form or order or due measure. In the physical order a thing is good in proportion as it possesses being. God alone is essentially being, and He alone is essentially and perfectlygood. Everything else possesses but a limited being, and, in so far as it possesses being, it is good. When it has its due proportion of form and order and measure it is, in its own order and degree, good. (See GOOD.) Evil implies a deficiency in perfection, hence it cannot exist in God who is essentially and by nature good; it is found only in finite beings which, because of their origin from nothing, are subject to the privation of form or order or measure due them, and, through the opposition they encounter, are liable to an increase or decrease of the perfection they have: "for evil, in a large sense, may be described as the sum of opposition, which experience shows to exist in the universe, to the desires and needs of individuals; whence arises, among human beings at least, the suffering in which life abounds" (see EVIL).

According to the nature of the perfection which it limits, evil is metaphysical, physical, or moral. Metaphysical evil is notevil properly so called; it is but the negation of a greater good, or the limitation of finite beings by other finite beings. Physical evil deprives the subject affected by it of some natural good, and is adverse to the well-being of the subject, as pain and suffering. Moral evil is found only in intelligent beings; it deprives them of some moral good. Here we have to deal with moral evil only. This may be defined as a privation of conformity to right reason and to the law of God. Since the morality of a human act consists in its agreement or non-agreement with right reason and the eternal law, an act isgood or evil in the moral order according as it involves this agreement or non-agreement. When the intelligent creature,knowing God and His law, deliberately refuses to obey, moral evil results.

Sin is nothing else than a morally bad act (St. Thomas, "De malo", 7:3), an act not in accord with reason informed by the Divine law. God has endowed us with reason and free-will, and a sense of responsibility; He has made us subject to His law, which is known to us by the dictates of conscience, and our acts must conform with these dictates, otherwise we sin (Romans 14:23). In every sinful act two things must be considered, the substance of the act and the want of rectitude or conformity (St. Thomas, I-II:72:1). The act is something positive. The sinner intends here and now to actin some determined matter, inordinately electing that particular good in defiance of God's law and the dictates of rightreason. The deformity is not directly intended, nor is it involved in the act so far as this is physical, but in the act as coming from the will which has power over its acts and is capable of choosing this or that particular good contained within the scope of its adequate object, i.e. universal good (St. Thomas, "De malo", Q. 3, a. 2, ad 2um). God, the firstcause of all reality, is the cause of the physical act as such, the free-will of the deformity (St. Thomas I-II:89:2; "De malo", 3:2). The evil act adequately considered has for its cause the free-will defectively electing some mutable good in place of the eternal good, God, and thus deviating from its true last end.

In every sin a privation of due order or conformity to the moral law is found, but sin is not a pure, or entire privation of all moral good (St. Thomas, "De malo", 2:9; I-II:73:2). There is a twofold privation; one entire which leaves nothing of its opposite, as for instance, darkness which leaves no light; another, not entire, which leaves something of the good to which it is opposed, as for instance, disease which does not entirely destroy the even balance of the bodily functionsnecessary for health. A pure or entire privation of good could occur in a moral act only on the supposition that the willcould incline to evil as such for an object. This is impossible because evil as such is not contained within the scope of the adequate object of the will, which is good. The sinner's intention terminates at some object in which there is a participation of God's goodness, and this object is directly intended by him. The privation of due order, or the deformity, is not directly intended, but is accepted in as much as the sinner's desire tends to an object in which this want of conformity is involved, so that sin is not a pure privation, but a human act deprived of its due rectitude. From the defect arises the evil of the act, from the fact that it is voluntary, its imputability.

Division of sin

As regards the principle from which it proceeds sin is original or actual. The will of Adam acting as head of the human race for the conservation or loss of original justice is the cause and source of original sin. Actual sin is committed by a free personal act of the individual will. It is divided into sins of commission and omission. A sin of commission is a positive act contrary to some prohibitory precept; a sin of omission is a failure to do what is commanded. A sin ofomission, however, requires a positive act whereby one wills to omit the fulfilling of a precept, or at least wills something incompatible with its fulfillment (I-II:72:5). As regards their malice, sins are distinguished into sins ofignorance, passion or infirmity, and malice; as regards the activities involved, into sins of thought, word, or deed(cordis, oris, operis); as regards their gravity, into mortal and venial. This last named division is indeed the most important of all and it calls for special treatment. But before taking up the details, it will be useful to indicate some further distinctions which occur in theology or in general usage.

Material and formal sin

This distinction is based upon the difference between the objective elements (object itself, circumstances) and the subjective (advertence to the sinfulness of the act). An action which, as a matter of fact, is contrary to the Divine lawbut is not known to be such by the agent constitutes a material sin; whereas formal sin is committed when the agent freely transgresses the law as shown him by his conscience, whether such law really exists or is only thought to exist by him who acts. Thus, a person who takes the property of another while believing it to be his own commits a materialsin; but the sin would be formal if he took the property in the belief that it belonged to another, whether his belief were correct or not.

Internal sins

That sin may be committed not only by outward deeds but also by the inner activity of the mind apart from any external manifestation, is plain from the precept of the Decalogue: "Thou shalt not covet", and from Christ's rebuke of thescribes and pharisees whom he likens to "whited sepulchres... full of all filthiness" (Matthew 23:27). Hence the Council of Trent (Sess. XIV, c. v), in declaring that all mortal sins must be confessed, makes special mention of those that are most secret and that violate only the last two precepts of the Decalogue, adding that they "sometimes more grievously wound the soul and are more dangerous than sins which are openly committed". Three kinds of internal sin are usually distinguished:

  • delectatio morosa, i.e. the pleasure taken in a sinful thought or imagination even without desiring it;
  • gaudium, i.e. dwelling with complacency on sins already committed; and
  • desiderium, i.e. the desire for what is sinful.

An efficacious desire, i.e. one that includes the deliberate intention to realize or gratify the desire, has the same malice, mortal or venial, as the action which it has in view. An inefficacious desire is one that carries a condition, in such a way that the will is prepared to perform the action in case the condition were verified. When the condition is such as to eliminate all sinfulness from the action, the desire involves no sin: e.g. I would gladly eat meat on Friday, if I had adispensation; and in general this is the case whenever the action is forbidden by positive law only. When the action is contrary to natural law and yet is permissible in given circumstances or in a particular state of life, the desire, if it include those circumstances or that state as conditions, is not in itself sinful: e.g. I would kill so-and-so if I had to do it in self-defence. Usually, however, such desires are dangerous and therefore to be repressed. If, on the other hand, thecondition does not remove the sinfulness of the action, the desire is also sinful. This is clearly the case where theaction is intrinsically and absolutely evil, e.g. blasphemy: one cannot without committing sin, have the desire -- I wouldblaspheme God if it were not wrong; the condition is an impossible one and therefore does not affect the desire itself. The pleasure taken in a sinful thought (delectatio, gaudium) is, generally speaking, a sin of the same kind and gravity as the action which is thought of. Much, however, depends on the motive for which one thinks of sinful actions. The pleasure, e.g. which one may experience in studying the nature of murder or any other crime, in getting clear ideas on the subject, tracing its causes, determining the guilt etc., is not a sin; on the contrary, it is often both necessary and useful. The case is different of course where the pleasure means gratification in the sinful object or action itself. And it is evidently a sin when one boasts of his evil deeds, the more so because of the scandal that is given.

The capital sins or vices

According to St. Thomas (II-II:153:4) "a capital vice is that which has an exceedingly desirable end so that in his desire for it a man goes on to the commission of many sins all of which are said to originate in that vice as their chief source". It is not then the gravity of the vice in itself that makes it capital but rather the fact that it gives rise to many othersins. These are enumerated by St. Thomas (I-II:84:4) as vainglory (pride), avarice, gluttony, lust, sloth, envy, anger.St. Bonaventure (Brevil., III, ix) gives the same enumeration. Earlier writers had distinguished eight capital sins: so St. Cyprian (De mort., iv); Cassian (Institutes 5, Conferences 5); Columbanus ("Instr. de octo vitiis princip." in "Bibl. max. vet. patr.", XII, 23); Alcuin (De virtut. et vitiis, xxvii sqq.). The number seven, however, had been given by St. Gregory the Great (Lib. mor. in Job. XXXI, xvii), and it was retained by the foremost theologians of the Middle Ages.

It is to be noted that "sin" is not predicated univocally of all kinds of sin. "The division of sin into venial and mortal is not a division of genus into species which participate equally the nature of the genus, but the division of an analogue into things of which it is predicated primarily and secondarily" (St. Thomas, I-II:88:1, ad 1um). "Sin is not predicated univocally of all kinds of sin, but primarily of actual mortal sin ... and therefore it is not necessary that the definition ofsin in general should be verified except in that sin in which the nature of the genus is found perfectly. The definition ofsin may be verified in other sins in a certain sense" (St. Thomas, II, d. 33, Q. i, a. 2, ad 2um). Actual sin primarily consists in a voluntary act repugnant to the order of right reason. The act passes, but the soul of the sinner remains stained, deprived of grace, in a state of sin, until the disturbance of order has been restored by penance. This state is called habitual sin, macula peccati. reatus culpæ (I-II:87:6).

The division of sin into original and actual, mortal and venial, is not a division of genus into species because sin has not the same signification when applied to original and personal sin, mortal and venial. Mortal sin cuts us off entirely from our true last end; venial sin only impedes us in its attainment. Actual personal sin is voluntary by a proper act of thewill. Original sin is voluntary not by a personal voluntary act of ours, but by an act of the will of Adam. Original and actual sin are distinguished by the manner in which they are voluntary (ex parte actus); mortal and venial sin by the way in which they affect our relation to God (ex parte deordinationis). Since a voluntary act and its disorder are of theessence of sin, it is impossible that sin should be a generic term in respect to original and actual, mortal and venial sin. The true nature of sin is found perfectly only in a personal mortal sin, in other sins imperfectly, so that sin is predicated primarily of actual sin, only secondarily of the others. Therefore we shall consider: first, personal mortal sin; second, venial sin.

Mortal sin

Mortal sin is defined by St. Augustine (Reply to Faustus XXII.27) as "Dictum vel factum vel concupitum contra legem æternam", i.e. something said, done or desired contrary to the eternal law, or a thought, word, or deed contrary to theeternal law. This is a definition of sin as it is a voluntary act. As it is a defect or privation it may be defined as an aversion from God, our true last end, by reason of the preference given to some mutable good. The definition of St. Augustine is accepted generally by theologians and is primarily a definition of actual mortal sin. It explains well the material and formal elements of sin. The words "dictum vel factum vel concupitum" denote the material element of sin, ahuman act: "contra legem æternam", the formal element. The act is bad because it transgresses the Divine law. St. Ambrose (De paradiso, viii) defines sin as a "prevarication of the Divine law". The definition of St. Augustine strictly considered, i.e. as sin averts us from our true ultimate end, does not comprehend venial sin, but in as much as venialsin is in a manner contrary to the Divine law, although not averting us from our last end, it may be said to be included in the definition as it stands. While primarily a definition of sins of commission, sins of omission may be included in the definition because they presuppose some positive act (St. Thomas, I-II:71:5) and negation and affirmation are reduced to the same genus. Sins that violate the human or the natural law are also included, for what is contrary to the human or natural law is also contrary to the Divine law, in as much as every just human law is derived from the Divine law, and is not just unless it is in conformity with the Divine law.

Biblical description of sin

In the Old Testament sin is set forth as an act of disobedience (Genesis 2:16-17; 3:11; Isaiah 1:2-4; Jeremiah 2:32); as an insult to God (Numbers 27:14); as something detested and punished by God (Genesis 3:14-19; Genesis 4:9-16); as injurious to the sinner (Tobit 12:10); to be expiated by penance (Psalm 1:19). In the New Testament it is clearly taught in St. Paul that sin is a transgression of the law (Romans 2:23; 5:12-20); a servitude from which we are liberated by grace (Romans 6:16-18); a disobedience (Hebrews 2:2) punished by God (Hebrews 10:26-31). St. Johndescribes sin as an offence to God, a disorder of the will (John 12:43), an iniquity (1 John 3:4-10). Christ in many of His utterances teaches the nature and extent of sin. He came to promulgate a new law more perfect than the old, which would extend to the ordering not only of external but also of internal acts to a degree unknown before, and, in His Sermon on the Mount, He condemns as sinful many acts which were judged honest and righteous by the doctors and teachers of the Old Law. He denounces in a special manner hypocrisy and scandal, infidelity and the sin against theHoly Ghost. In particular He teaches that sins come from the heart (Matthew 15:19-20).

Systems which deny sin or distort its true notion

All systems, religious and ethical, which either deny, on the one hand, the existence of a personal creator and lawgiver distinct from and superior to his creation, or, on the other, the existence of free will and responsibility in man, distort or destroy the true biblico-theological notion of sin. In the beginning of the Christian era the Gnostics, although their doctrines varied in details, denied the existence of a personal creator. The idea of sin in the Catholic sense is not contained in their system. There is no sin for them, unless it be the sin of ignorance, no necessity for an atonement;Jesus is not God (see GNOSTICISM). Manichaeism with its two eternal principles, good and evil, at perpetual war with each other, is also destructive of the true notion of sin. All evil, and consequently sin, is from the principle of evil. TheChristian concept of God as a lawgiver is destroyed. Sin is not a conscious voluntary act of disobedience to the Divinewill. Pantheistic systems which deny the distinction between God and His creation make sin impossible. If man and Godare one, man is not responsible to anyone for his acts, morality is destroyed. If he is his own rule of action, he cannot deviate from right as St. Thomas teaches (I:63:1). The identification of God and the world by Pantheism leaves no place for sin.

There must be some law to which man is subject, superior to and distinct from him, which can be obeyed and transgressed, before sin can enter into his acts. This law must be the mandate of a superior, because the notions of superiority and subjection are correlative. This superior can be only God, who alone is the author and lord of man.Materialism, denying as it does the spirituality and the immortality of the soul, the existence of any spirit whatsoever, and consequently of God, does not admit sin. There is no free will, everything is determined by the inflexible laws of motion. "Virtue" and "vice" are meaningless qualifications of action. Positivism places man's last end in some sensiblegood. His supreme law of action is to seek the maximum of pleasure. Egotism or altruism is the supreme norm and criterion of the Positivistic systems, not the eternal law of God as revealed by Him, and dictated by conscience. For thematerialistic evolutionists man is but a highly-developed animal, conscience a product of evolution. Evolution has revolutionized morality, sin is no more.

Kant in his "Critique of Pure Reason" having rejected all the essential notions of true morality, namely, liberty, the soul,God and a future life, attempted in his "Critique of the Practical Reason" to restore them in the measure in which they are necessary for morality. The practical reason, he tells us, imposes on us the idea of law and duty. The fundamental principle of the morality of Kant is "duty for duty's sake", not God and His law. Duty cannot be conceived of alone as an independent thing. It carries with it certain postulates, the first of which is liberty. "I ought, therefore I can", is hisdoctrine. Man by virtue of his practical reason has a consciousness of moral obligation (categorical imperative). Thisconsciousness supposes three things: free will, the immortality of the soul, the existence of God, otherwise man would not be capable of fulfilling his obligations, there would be no sufficient sanction for the Divine law, no reward or punishment in a future life. Kant's moral system labours in obscurities and contradictions and is destructive of much that pertains to the teaching of Christ. Personal dignity is the supreme rule of man's actions. The notion of sin as opposed toGod is suppressed. According to the teaching of materialistic Monism, now so widespread, there is, and can be, no free will. According to this doctrine but one thing exists and this one being produces all phenomena, thought included; we are but puppets in its hands, carried hither an thither as it wills, and finally are cast back into nothingness. There is no place for good and evil, a free observance or a wilful transgression of law, in such a system. Sin in the true sense is impossible. Without law and liberty and a personal God there is no sin.

That God exists and can be known from His visible creation, that He has revealed the decrees of His eternal will to man, and is distinct from His creatures (Denzinger-Bannwart, "Enchiridion", nn. 1782, 1785, 1701), are matters of Catholicfaith and teaching. Man is a created being endowed with free will (ibid., 793), which fact can be proved from Scriptureand reason (ibid., 1041-1650). The Council of Trent declares in Sess. VI, c. i (ibid., 793) that man by reason of the prevarication of Adam has lost his primeval innocence, and that while free will remains, its powers are lessened (seeORIGINAL SIN).

Protestant errors

Luther and Calvin taught as their fundamental error that no free will properly so called remained in man after the fall of our first parents; that the fulfillment of God's precepts is impossible even with the assistance of grace, and that man in all his actions sins. Grace is not an interior gift, but something external. To some sin is not imputed, because they are covered as with a cloak by the merits of Christ. Faith alone saves, there is no necessity for good works. Sin in Luther'sdoctrine cannot be a deliberate transgression of the Divine law. Jansenius, in his "Augustinus", taught that according to the present powers of man some of God's precepts are impossible of fulfilment, even to the just who strive to fulfil them, and he further taught that grace by means of which the fulfilment becomes possible is wanting even to the just. His fundamental error consists in teaching that the will is not free but is necessarily drawn either by concupiscence orgrace. Internal liberty is not required for merit or demerit. Liberty from coercion suffices. Christ did not die for all men.Baius taught a semi-Lutheran doctrine. Liberty is not entirely destroyed, but is so weakened that without grace it can do nothing but sin. True liberty is not required for sin. A bad act committed involuntarily renders man responsible (propositions 50-51 in Denzinger-Bannwart, "Enchiridion", nn. 1050-1). All acts done without charity are mortal sins andmerit damnation because they proceed from concupiscence. This doctrine denies that sin is a voluntary transgression ofDivine law. If man is not free, a precept is meaningless as far as he is concerned.

Philosophical sin

Those who would construct a moral system independent of God and His law distinguish between theological andphilosophical sin. Philosophical sin is a morally bad act which violates the natural order of reason, not the Divine law.Theological sin is a transgression of the eternal law. Those who are of atheistic tendencies and contend for this distinction, either deny the existence of God or maintain that He exercises no providence in regard to human acts. This position is destructive of sin in the theological sense, as God and His law, reward and punishment, are done away with. Those who admit the existence of God, His law, human liberty and responsibility, and still contend for a distinction between philosophical and theological sin, maintain that in the present order of God's providence there are morally badacts, which, while violating the order of reason, are not offensive to God, and they base their contention on this that the sinner can be ignorant of the existence of God, or not actually think of Him and His law when he acts. Without theknowledge of God and consideration of Him, it is impossible to offend Him. This doctrine was censured as scandalous, temerarious, and erroneous by Alexander VIII (24 Aug., 1690) in his condemnation of the following proposition: "Philosophical or moral sin is a human act not in agreement with rational nature and right reason, theological and mortalsin is a free transgression of the Divine law. However grievous it may be, philosophical sin in one who is either ignorantof God or does not actually think of God, is indeed a grievous sin, but not an offense to God, nor a mortal sin dissolving friendship with God, nor worthy of eternal punishment" (Denzinger-Bannwart, 1290).

This proposition is condemned because it does not distinguish between vincible and invincible ignorance, and further supposes invincible ignorance of God to be sufficiently common, instead of only metaphysically possible, and because in the present dispensation of God's providence we are clearly taught in Scripture that God will punish all evil coming from the free will of man (Romans 2:5-11). There is no morally bad act that does not include a transgression of Divine law. From the fact that an action is conceived of as morally evil it is conceived of as prohibited. A prohibition is unintelligible without the notion of some one prohibiting. The one prohibiting in this case and binding the conscience of man can be only God, Who alone has power over man's free will and actions, so that from the fact that any act is perceived to bemorally bad and prohibited by conscience, God and His law are perceived at least confusedly, and a wilful transgression of the dictate of conscience is necessarily also a transgression of God's law. Cardinal de Lugo (De incarnat., disp. 5, lect. 3) admits the possibility of philosophical sin in those who are inculpably ignorant of God, but he holds that it does not actually occur, because in the present order of God's providence there cannot be invincible ignorance of God and His law. This teaching does not necessarily fall under the condemnation of Alexander VIII, but it is commonly rejected by theologians for the reason that a dictate of conscience necessarily involves a knowledge of the Divine law as a principle of morality.

Conditions of mortal sin: knowledge, free will, grave matter

Contrary to the teaching of Baius (prop. 46, Denzinger-Bannwart, 1046) and the Reformers, a sin must be a voluntaryact. Those actions alone are properly called human or moral actions which proceed from the human will deliberatelyacting with knowledge of the end for which it acts. Man differs from all irrational creatures in this precisely that he is master of his actions by virtue of his reason and free will (I-II:1:1). Since sin is a human act wanting in due rectitude, it must have, in so far as it is a human act, the essential constituents of a human act. The intellect must perceive and judge of the morality of the act, and the will must freely elect. For a deliberate mortal sin there must be full advertence on the part of the intellect and full consent on the part of the will in a grave matter. An involuntary transgression of thelaw even in a grave matter is not a formal but a material sin. The gravity of the matter is judged from the teaching ofScripture, the definitions of councils and popes, and also from reason. Those sins are judged to be mortal which contain in themselves some grave disorder in regard to God, our neighbour, ourselves, or society. Some sins admit of no lightness of matter, as for example, blasphemy, hatred of God; they are always mortal (ex toto genere suo), unless rendered venial by want of full advertence on the part of the intellect or full consent on the part of the will. Other sins admit lightness of matter: they are grave sins (ex genere suo) in as much as their matter in itself is sufficient to constitute a grave sin without the addition of any other matter, but is of such a nature that in a given case, owing to its smallness, the sin may be venial, e.g. theft.


That the act of the sinner may be imputed to him it is not necessary that the object which terminates and specifies hisact should be directly willed as an ends or means. It suffices that it be willed indirectly or in its cause, i.e. if the sinner foresees, at least confusedly, that it will follow from the act which he freely performs or from his omission of an act. When the cause produces a twofold effect, one of which is directly willed, the other indirectly, the effect which follows indirectly is morally imputable to the sinner when these three conditions are verified:

  • first, the sinner must foresee at least confusedly the evil effects which follow on the cause he places;
  • second, he must be able to refrain from placing the cause;
  • third, he must be under the obligation of preventing the evil effect.

Error and ignorance in regard to the object or circumstances of the act to be placed, affect the judgment of theintellect and consequently the morality and imputability of the act. Invincible ignorance excuses entirely from sin. Vincible ignorance does not, although it renders the act less free (see IGNORANCE). The passions, while they disturb the judgment of the intellect, more directly affect the will. Antecedent passion increases the intensity of the act, the object is more intensely desired, although less freely, and the disturbance caused by the passions may be so great as to render a free judgment impossible, the agent being for the moment beside himself (I-II:6:7, ad 3um). Consequentpassion, which arises from a command of the will, does not lessen liberty, but is rather a sign of an intense act of volition. Fear, violence, heredity, temperament and pathological states, in so far as they affect free volition, affect the malice and imputability of sin. From the condemnation of the errors of Baius and Jansenius (Denz.-Bann., 1046, 1066, 1094, 1291-2) it is clear that for an actual personal sin a knowledge of the law and a personal voluntary act, free from coercion and necessity, are required. No mortal sin is committed in a state of invincible ignorance or in a half-conscious state. Actual advertence to the sinfulness of the act is not required, virtual advertence suffices. It is not necessarythat the explicit intention to offend God and break His law be present, the full and free consent of the will to an evil actsuffices.


The true malice of mortal sin consists in a conscious and voluntary transgression of the eternal law, and implies a contempt of the Divine will, a complete turning away from God, our true last end, and a preferring of some created thing to which we subject ourselves. It is an offence offered to God, and an injury done Him; not that it effects any change in God, who is immutable by nature, but that the sinner by his act deprives God of the reverence and honor due Him: it is not any lack of malice on the sinner's part, but God's immutability that prevents Him from suffering. As an offence offered to God mortal sin is in a way infinite in its malice, since it is directed against an infinite being, and the gravity of the offence is measured by the dignity of the one offended (St. Thomas, III:1:2, ad 2um). As an act sin is finite, thewill of man not being capable of infinite malice. Sin is an offence against Christ Who has redeemed man (Philippians 3:18); against the Holy Ghost Who sanctifies us (Hebrews 10:29), an injury to man himself, causing the spiritual death of the soul, and making man the servant of the devil. The first and primary malice of sin is derived from the object to which the will inordinately tends, and from the object considered morally, not physically. The end for which the sinneracts and the circumstances which surround the act are also determining factors of its morality. An act which, objectively considered, is morally indifferent, may be rendered good or evil by circumstances, or by the intention of thesinner. An act that is good objectively may be rendered bad, or a new species of good or evil may be added, or a new degree. Circumstances can change the character of a sin to such a degree that it becomes specifically different from what it is objectively considered; or they may merely aggravate the sin while not changing its specific character; or they may lessen its gravity. That they may exercise this determining influence two things are necessary: they must contain in themselves some good or evil, and must be apprehended, at least confusedly, in their moral aspect. The external act, in so far as it is a mere execution of a voluntary efficacious internal act, does not, according to the common Thomistic opinion, add any essential goodness or malice to the internal sin.


While every mortal sin averts us from our true last end, all mortal sins are not equally grave, as is clear from Scripture(John 19:11; Matthew 11:22; Luke 6), and also from reason. Sins are specifically distinguished by their objects, which do not all equally avert man from his last end. Then again, since sin is not a pure privation, but a mixed one, all sins do not equally destroy the order of reason. Spiritual sins, other things being equal, are graver than carnal sins. (St. Thomas, "De malo", Q. ii, a. 9; I-II.73.5).

Specific and numeric distinction of sin

Sins are distinguished specifically by their formally diverse objects; or from their opposition to different virtues, or tomorally different precepts of the same virtue. Sins that are specifically distinct are also numerically distinct. Sins within the same species are distinguished numerically according to the number of complete acts of the will in regard to total objects. A total object is one which, either in itself or by the intention of the sinner, forms a complete whole and is not referred to another action as a part of the whole. When the completed acts of the will relate to the same object there are as many sins as there are morally interrupted acts.

Subject causes of sin

Since sin is a voluntary act lacking in due rectitude, sin is found, as in a subject, principally in the will. But, since not only acts elicited by the will are voluntary, but also those that are elicited by other faculties at the command of thewill, sin may be found in these faculties in so far as they are subject in their actions to the command of the will, and are instruments of the will, and move under its guidance (I-II:74).

The external members of the body cannot be effective principles of sin (I-II:74:2, ad 3um). They are mere organs which are set in activity by the soul; they do not initiate action. The appetitive powers on the contrary can be effective principles of sin, for they possess, through their immediate conjunction with the will and their subordination to it, a certain though imperfect liberty (I-II:56:4, ad 3um). The sensual appetites have their own proper sensible objects to which they naturally incline, and since original sin has broken the bond which held them in complete subjection to thewill, they may antecede the will in their actions and tend to their own proper objects inordinately. Hence they may be proximate principles of sin when they move inordinately contrary to the dictates of right reason.

It is the right of reason to rule the lower faculties, and when the disturbance arises in the sensual part the reason may do one of two things: it may either consent to the sensible delectation or it may repress and reject it. If it consents, the sin is no longer one of the sensual part of man, but of the intellect and will, and consequently, if the matter is grave, mortal. If rejected, no sin can be imputed. There can be no sin in the sensual part of man independently of thewill. The inordinate motions of the sensual appetite which precede the advertence of reason, or which are suffered unwillingly, are not even venial sins. The temptations of the flesh not consented to are not sins. Concupiscence, which remains after the guilt of original sin is remitted in baptism, is not sinful so long as consent is not given to it (Council of Trent, sess. V, can. v). The sensual appetite of itself cannot be the subject of mortal sin, for the reason that it can neither grasp the notion of God as an ultimate end, nor avert us from Him, without which aversion there cannot be mortal sin. The superior reason, whose office it is to occupy itself with Divine things, may be the proximate principle ofsin both in regard to its own proper act, to know truth, and as it is directive of the inferior faculties: in regard to its own proper act, in so far as it voluntarily neglects to know what it can and ought to know; in regard to the act by which it directs the inferior faculties, to the extent that it commands inordinate acts or fails to repress them (I-II:74:7, ad 2um).

The will never consents to a sin that is not at the same time a sin of the superior reason as directing badly, by either actually deliberating and commanding the consent, or by failing to deliberate and impede the consent of the will when it could and should do so. The superior reason is the ultimate judge of human acts and has an obligation of deliberating and deciding whether the act to be performed is according to the law of God. Venial sin may also be found in the superior reason when it deliberately consents to sins that are venial in their nature, or when there is not a full consentin the case of a sin that is mortal considered objectively.

Causes of sin

Under this head, it is needful to distinguish between the efficient cause, i.e. the agent performing the sinful action, and those other agencies, influences or circumstances, which incite to sin and consequently involve a danger, more or less grave, for one who is exposed to them. These inciting causes are explained in special articles on OCCASIONS OF SINand TEMPTATION. Here we have to consider only the efficient cause or causes of sin. These are interior and exterior. The complete and sufficient cause of sin is the will, which is regulated in its actions by the reason, and acted upon by the sensitive appetites. The principal interior causes of sin are ignorance, infirmity or passion, and malice. Ignorance on the part of the reason, infirmity and passion on the part of the sensitive appetite, and malice on the part of the will. Asin is from certain malice when the will sins of its own accord and not under the influence of ignorance or passion.

The exterior causes of sin are the devil and man, who move to sin by means of suggestion, persuasion, temptation and bad example. God is not the cause of sin (Council of Trent, sess. VI, can. vi, in Denz.-Bann., 816). He directs all things to Himself and is the end of all His actions, and could not be the cause of evil without self-contradiction. Of whatever entity there is in sin as an action, He is the cause. The evil will is the cause of the disorder (I-II:79:2). One sin may be the cause of another inasmuch as one sin may be ordained to another as an end. The seven capital sins, so called, may be considered as the source from which other sins proceed. They are sinful propensities which reveal themselves in particular sinful acts. Original sin by reason of its dire effects is the cause and source of sin in so far as by reason of it our natures are left wounded and inclined to evil. Ignorance, infirmity, malice, and concupiscence are the consequences of original sin.

Effects of sin

The first effect of mortal sin in man is to avert him from his true last end, and deprive his soul of sanctifying grace. Thesinful act passes, and the sinner is left in a state of habitual aversion from God. The sinful state is voluntary and imputable to the sinner, because it necessarily follows from the act of sin he freely placed, and it remains until satisfaction is made (see PENANCE). This state of sin is called by theologians habitual sin, not in the sense that habitualsin implies a vicious habit, but in the sense that it signifies a state of aversion from God depending on the preceding actual sin, consequently voluntary and imputable. This state of aversion carries with it necessarily in the present order of God's providence the privation of grace and charity by means of which man is ordered to his supernatural end. The privation of grace is the "macula peccati" (St. Thomas, I-II.86), the stain of sin spoken of in Scripture (Joshua 22:17;Isaiah 4:4; 1 Corinthians 6:11). It is not anything positive, a quality or disposition, an obligation to suffer, an extrinsic denomination coming from sin, but is solely the privation of sanctifying grace. There is not a real but only a conceptual distinction between habitual sin (reatus culpæ) and the stain of sin (macula peccati). One and the same privation considered as destroying the due order of man to God is habitual sin, considered as depriving the soul of the beauty ofgrace is the stain or "macula" of sin.

The second effect of sin is to entail the penalty of undergoing suffering (reatus pænæ). Sin (reatus culpæ) is the causeof this obligation (reatus pænæ ). The suffering may be inflicted in this life through the medium of medicinal punishments, calamities, sickness, temporal evils, which tend to withdraw from sin; or it may be inflicted in the life to come by the justice of God as vindictive punishment. The punishments of the future life are proportioned to the sin committed, and it is the obligation of undergoing this punishment for unrepented sin that is signified by the "reatus poenæ" of the theologians. The penalty to be undergone in the future life is divided into the pain of loss (pæna damni) and the pain of sense (pæna sensus). The pain of loss is the privation of the beatific vision of God in punishment of turning away from Him. The pain of sense is suffering in punishment of the conversion to some created thing in place ofGod. This two-fold pain in punishment of mortal sin is eternal (1 Corinthians 6:9; Matthew 25:41; Mark 9:45). One mortal sin suffices to incur punishment. (See HELL.) Other effects of sins are: remorse of conscience (Wisdom 5:2-13); an inclination towards evil, as habits are formed by a repetition of similar acts; a darkening of the intelligence, a hardening of the will (Matthew 13:14-15; Romans 11:8); a general vitiating of nature, which does not however totally destroy the substance and faculties of the soul but merely weakens the right exercise of its faculties.

Venial sin

Venial sin is essentially different from mortal sin. It does not avert us from our true last end, it does not destroy charity, the principle of union with God, nor deprive the soul of sanctifying grace, and it is intrinsically reparable. It is called venial precisely because, considered in its own proper nature, it is pardonable; in itself meriting, not eternal, but temporal punishment. It is distinguished from mortal sin on the part of the disorder. By mortal sin man is entirely averted from God, his true last end, and, at least implicitly, he places his last end in some created thing. By venial sin he is not averted from God, neither does he place his last end in creatures. He remains united with God by charity, but does not tend towards Him as he ought. The true nature of sin as it is contrary to the eternal law, repugnant namely to the primary end of the law, is found only in mortal sin. Venial sin is only in an imperfect way contrary to the law, since it is not contrary to the primary end of the law, nor does it avert man from the end intended by the law. (St. Thomas, I-II.88.1; and Cajetan, I-II, Q. lxxxviii, a. 1, for the sense of the præter legem and contra legem of St. Thomas).


Since a voluntary act and its disorder are of the essence of sin, venial sin as it is a voluntary act may be defined as a thought, word or deed at variance with the law of God. It retards man in the attainment of his last end while not averting him from it. Its disorder consists either in the not fully deliberate choosing of some object prohibited by the law of God, or in the deliberate adhesion to some created object not as an ultimate end but as a medium, which object does not avert the sinner from God, but is not, however, referable to Him as an end. Man cannot be averted from God except by deliberately placing his last end in some created thing, and in venial sin he does not adhere to any temporal good, enjoying it as a last end, but as a medium referring it to God not actually but habitually inasmuch as he himself is ordered to God by charity. "Ille qui peccat venialiter, inhæret bono temporali non ut fruens, quia non constituit in eo finem, sed ut utens, referens in Deum non actu sed habitu" (I-II:88:1, ad 3). For a mortal sin, some created good must be adhered to as a last end at least implicitly. This adherence cannot be accomplished by a semi-deliberate act. By adhering to an object that is at variance with the law of God and yet not destructive of the primary end of the Divine law, a true opposition is not set up between God and that object. The created good is not desired as an end. Thesinner is not placed in the position of choosing between God and creature as ultimate ends that are opposed, but is in such a condition of mind that if the object to which he adheres were prohibited as contrary to his true last end he would not adhere to it, but would prefer to keep friendship with God. An example may be had in human friendship. A friend will refrain from doing anything that of itself will tend directly to dissolve friendship while allowing himself at times to do what is displeasing to his friends without destroying friendship.

The distinction between mortal and venial sin is set forth in Scripture. From St. John (1 John 5:16-17) it is clear there are some sins "unto death" and some sins not "unto death", i.e. mortal and venial. The classic text for the distinction of mortal and venial sin is that of St. Paul (1 Corinthians 3:8-15), where he explains in detail the distinction between mortal and venial sin. "For other foundation no man can lay, but that which is laid; which is Christ Jesus. Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble: every man's work shall be manifest; for the day of the Lord shall declare it; because it shall be revealed in fire; and the fire shall try every man's work, of what sort it is. If any man's work abide, which he hath built thereupon, he shall receive a reward. If any man's work burn, he shall suffer loss; but he himself shall be saved, yet so as by fire." By wood, hay, and stubble are signified venial sins (St. Thomas, I-II:89:2) which, built on the foundation of a living faith in Christ, do not destroy charity, and from their verynature do not merit eternal but temporal punishment. "Just as", says St. Thomas, [wood, hay, and stubble] "are gathered together in a house and do not pertain to the substance of the edifice, so also venial sins are multiplied inman, the spiritual edifice remaining, and for these he suffers either the fire of temporal tribulations in this life, or ofpurgatory after this life and nevertheless obtains eternal salvation." (I-II:89:2)

The suitableness of the division into wood, hay, and stubble is explained by St. Thomas (iv, dist. 21, Q. i, a. 2). Some venial sins are graver than others and less pardonable, and this difference is well signified by the difference in the inflammability of wood, hay, and stubble. That there is a distinction between mortal and venial sins is of faith (Council of Trent, sess. VI, c. xi and canons 23-25; sess. XIV, de poenit., c. v). This distinction is commonly rejected by allheretics ancient and modern. In the fourth century Jovinian asserted that all sins are equal in guilt and deserving of the same punishment (St. Aug., "Ep. 167", ii, n. 4); Pelagius, that every sin deprives man of justice and therefore is mortal;Wyclif, that there is no warrant in Scripture for differentiating mortal from venial sin, and that the gravity of sin depends not on the quality of the action but on the decree of predestination or reprobation so that the worst crime of thepredestined is infinitely less than the slightest fault of the reprobate; Hus, that all the actions of the vicious are mortalsins, while all the acts of the good are virtuous (Denz.-Bann., 642); Luther, that all sins of unbelievers are mortal and allsins of the regenerate, with the exception of infidelity, are venial; Calvin, like Wyclif, bases the difference between mortal sin and venial sin on predestination, but adds that a sin is venial because of the faith of the sinner. The twentieth among the condemned propositions of Baius reads: "There is no sin venial in its nature, but every sin meritseternal punishment" (Denz.-Bann., 1020). Hirscher in more recent times taught that all sins which are fully deliberate are mortal, thus denying the distinction of sins by reason of their objects and making the distinction rest on the imperfection of the act (Kleutgen, 2nd ed., II, 284, etc.).

Malice of venial sin

The difference in the malice of mortal and venial sin consists in this: that mortal sin is contrary to the primary end of the eternal law, that it attacks the very substance of the law which commands that no created thing should be preferred to God as an end, or equalled to Him, while venial sin is only at variance with the law, not in contrary opposition to it, not attacking its substance. The substance of the law remaining, its perfect accomplishment is prevented by venial sin.


Venial sin is committed when the matter of the sin is light, even though the advertence of the intellect and consent of the will are full and deliberate, and when, even though the matter of the sin be grave, there is not full advertence on the part of the intellect and full consent on the part of the will. A precept obliges sub gravi when it has for its object an important end to be attained, and its transgression is prohibited under penalty of losing God's friendship. A preceptobliges sub levi when it is not so directly imposed.


Venial sin does not deprive the soul of sanctifying grace, or diminish it. It does not produce a macula, or stain, as does mortal sin, but it lessens the lustre of virtue -- "In anima duplex est nitor, unus quiden habitualis, ex gratia sanctificante, alter actualis ex actibus virtutem, jamvero peccatum veniale impedit quidem fulgorem qui ex actibus virtutum oritur, non autem habitualem nitorem, quia non excludit nec minuit habitum charitatis" (I-II:89:1). Frequent and deliberate venial sin lessens the fervour of charity, disposes to mortal sin (I-II:88:3), and hinders the reception ofgraces God would otherwise give. It displeases God (Revelation 2:4-5) and obliges the sinner to temporal punishment either in this life or in Purgatory. We cannot avoid all venial sin in this life. "Although the most just and holy occasionally during this life fall into some slight and daily sins, known as venial, they cease not on that account to be just" (Council of Trent, sess. VI, c. xi). And canon xxiii says: "If any one declare that a man once justified cannot sin again, or that he can avoid for the rest of his life every sin, even venial, let him be anathema", but according to the common opinion we can avoid all such as are fully deliberate. Venial sin may coexist with mortal sin in those who are averted from Godby mortal sin. This fact does not change its nature or intrinsic reparability, and the fact that it is not coexistent withcharity is not the result of venial sin, but of mortal sin. It is per accidens, for an extrinsic reason, that venial sin in this case is irreparable, and is punished in hell. That venial sin may appear in its true nature as essentially different from mortal sin it is considered as de facto coexisting with charity (1 Corinthians 3:8-15). Venial sins do not need the graceof absolution. They can be remitted by prayer, contrition, fervent communion, and other pious works. Nevertheless it is laudable to confess them (Denz.-Bann., 1539).

Permission of sin and remedies

Since it is of faith that God is omnipotent, omniscient, and all good it is difficult to account for sin in His creation. Theexistence of evil is the underlying problem in all theology. Various explanations to account for its existence have been offered, differing according to the philosophical principles and religious tenets of their authors. Any Catholic explanation must take into account the defined truths of the omnipotence, omniscience, and goodness of God; free will on the part of man; and the fact that suffering is the penalty of sin. Of metaphysical evil, the negation of a greater good, God is the cause inasmuch as he has created beings with limited forms. Of physical evil (malum pænæ) He is also the cause. Physical evil, considered as it proceeds from God and is inflicted in punishment of sin in accordance with the decrees of Divine justice, is good, compensating for the violation of order by sin. It is only in the subject affected by it that it isevil.

Of moral evil (malum culpæ) God is not the cause (Council of Trent, sess. VI, can. vi), either directly or indirectly. Sin is a violation of order, and God orders all things to Himself, as an ultimate end, consequently He cannot be the directcause of sin. God's withdrawal of grace which would prevent the sin does not make Him the indirect cause of sin inasmuch as this withdrawal is affected according to the decrees of His Divine wisdom and justice in punishment of previous sin. He is under no obligation of impeding the sin, consequently it cannot be imputed to Him as a cause (I-II:79:1). When we read in Scripture and the Fathers that God inclines men to sin the sense is, either that in His justjudgment He permits men to fall into sin by a punitive permission, exercising His justice in punishment of past sin; or that He directly causes, not sin, but certain exterior works, good in themselves, which are so abused by the evil wills ofmen that here and now they commit evil; or that He gives them the power of accomplishing their evil designs. Of the physical act in sin God is the cause inasmuch as it is an entity and good. Of the malice of sin man's evil will is the sufficient cause. God could not be impeded in the creation of man by the fact that He foresaw his fall. This would mean the limiting of His omnipotence by a creature, and would be destructive of Him. He was free to create man even though He foresaw his fall, and He created him, endowed him with free will, and gave him sufficient means of persevering ingood had he so willed. We must sum up our ignorance of the permission of evil by saying in the words of St. Augustine, that God would not have permitted evil had He not been powerful enough to bring good out of evil. God's end in creatingthis universe is Himself, not the good of man, and somehow or other good and evil serve His ends, and there shall finally be a restoration of violated order by Divine justice. No sin shall be without its punishment. The evil men do must beatoned for either in this world by penance (see PENANCE) or in the world to come in purgatory or hell, according as thesin that stains the soul, and is not repented of, is mortal or venial, and merits eternal or temporal punishment. (SeeEVIL.) God has provided a remedy for sin and manifested His love and goodness in the face of man's ingratitude by theIncarnation of His Divine Son (see INCARNATION); by the institution of His Church to guide men and interpret to them His law, and administer to them the sacraments, seven channels of grace, which, rightly used, furnish an adequate remedy for sin and a means to union with God in heaven, which is the end of His law.

Sense of sin

The understanding of sin, as far as it can be understood by our finite intelligence, serves to unite man more closely toGod. It impresses him with a salutary fear, a fear of his own powers, a fear, if left to himself, of falling from grace; with the necessity he lies under of seeking God's help and grace to stand firm in the fear and love of God, and make progress in the spiritual life. Without the acknowledgment that the present moral state of man is not that in which God createdhim, that his powers are weakened; that he has a supernatural end to attain, which is impossible of attainment by his own unaided efforts, without grace there being no proportion between the end and the means; that the world, the flesh, and the devil are in reality active agents fighting against him and leading him to serve them instead of God, sin cannot be understood. The evolutionary hypothesis would have it that physical evolution accounts for the physical origin of man, that science knows no condition of man in which man exhibited the characteristics of the state of originaljustice, no state of sinlessness. The fall of man in this hypothesis is in reality a rise to a higher grade of being. "A fall it might seem, just as a vicious man sometimes seems degraded below the beasts, but in promise and potency, a rise it really was" (Sir O. Lodge, "Life and Matter", p. 79). This teaching is destructive of the notion of sin as taught by theCatholic Church. Sin is not a phase of an upward struggle, it is rather a deliberate, wilful refusal to struggle. If there has been no fall from a higher to a lower state, then the teaching of Scripture in regard to Redemption and the necessity of a baptismal regeneration is unintelligible. The Catholic teaching is the one that places sin in its true light, that justifies the condemnation of sin we find in Scripture.

The Church strives continually to impress her children with a sense of the awfulness of sin that they may fear it and avoid it. We are fallen creatures, and our spiritual life on earth is a warfare. Sin is our enemy, and while of our own strength we cannot avoid sin, with God's grace we can. If we but place no obstacle to the workings of grace we can avoid all deliberate sin. If we have the misfortune to sin, and seek God's grace and pardon with a contrite and humbleheart, He will not repel us. Sin has its remedy in grace, which is given us by God, through the merits of His only-begotten Son, Who has redeemed us, restoring by His passion and death the order violated by the sin of our first parents, and making us once again children of God and heirs of heaven. Where sin is looked on as a necessary and unavoidable condition of things human, where inability to avoid sin is conceived as necessary, discouragement naturally follows. Where the Catholic doctrine of the creation of man in a superior state, his fall by a wilful transgression, the effects of which fall are by Divine decree transmitted to his posterity, destroying the balance of the human facultiesand leaving man inclined to evil; where the dogmas of redemption and grace in reparation of sin are kept in mind, there is no discouragement. Left to ourselves we fall, by keeping close to God and continually seeking His help we can stand and struggle against sin, and if faithful in the battle we must wage shall be crowned in heaven. (See CONSCIENCE;JUSTIFICATION; SCANDAL.)


DOGMATIC WORKS: ST. THOMAS, Summa theol., I-II, QQ. lxxi-lxxxix; IDEM, Contra gentes, tr. RICKABY, Of God and His Creatures (London, 1905); IDEM, Quaest. disputatae: De malo in Opera omnia (Paris, 1875); BILLUART, De peccatis (Paris, 1867-72); SUAREZ, De pecc. in Opera omnia(Paris, 1878); SALMANTICENSES, De pecc. in Curs. theol. (Paris, 1877); GONET, Clypeus theol. thom. (Venice, 1772); JOHN OF ST. THOMAS, De pecc. in Curs. theol. (Paris, 1886); SYLVIUS, De pecc. (Antwerp, 1698); Catechismus Romanus, tr. DONOVAN, Catechism of the Council of Trent(Dublin, 1829); SCHEEBEN, Handbuch d. kath. Dogmatik (Freiburg, 1873-87); MANNING, Sin and its Consequences (New York, 1904); SHARPE,Principles of Christianity (London, 1904); IDEM, Evil, its Nature and Cause (London, 1906); BILLOT, De nat. et rat. peccati personalis (Rome, 1900); TANQUEREY, Synopsis theol., I (New York, 1907).