Introduction

Every properly human action is aimed at some good. Eating nourishes the body. Conversing spreads the truth. Procreating perpetuates the species. Generally speaking, the attainment of such goods perfects the human person. While there are many things that are good for man, a person’s pursuit of such goods must be ordered, or else man quickly becomes disordered. The ordering principle of human action in the life of the Christian is charity, “the theological virtue by which we love God above all things for his own sake, and our neighbors as ourselves for the love of God” (CCC no. 1862). Actions that are contrary to this order are called sins. Like all human actions, sinful actions are done in pursuit of something good—fornication is done in pursuit of pleasure, excessive drinking can be done in view of fostering comradery, but they are done in such a way that they violate the order set by charity, thereby offending God (CCC no. 1850), wounding the nature of man, and injuring human solidarity (CCC no. 1849). This is most evident in cases where a person uses one of his faculties without respect for its purpose, that is, without respect for the order in which it is supposed to be used. Thus, while eating nourishes the body, eating unhealthy food is a detriment to the health of the body. Conversing spreads the truth, but lying spreads error and ignorance. Procreation perpetuates the human species, but fornication does so in such a way that neglects the new members of the species, depriving them of that care and stability which they are owed in justice.

There are, however, many types of sins. This is made clear by the classical definition of sin: “an utterance, a deed, or a desire contrary to the eternal law,” (CCC no. 1849). {1} Christ himself summarizes this definition succinctly when he enjoins us to love God above all things and our neighbor as ourselves. (cf. Mk 12:30-31; Mt 22:36-40). Just as there are many ways to violate the law or to act contrary to the virtue of charity, so there are many ways to sin. The purpose of the present article will be to understand how these various sinful actions originate, what they are, what their effects are, and what to do about them.

Physical Evil vs. Moral Evil

Sin is, of course, evil, but the type of evil that it is stands in need of clarification. After all, no one would hesitate to call a famine evil, but a famine is not a sin. This is because famine is not an action, and sin clearly pertains to human action. But neither can one simply say that disordered human action is a sin, for then someone with a limp would sin when walking.

Such evils as famines and limps are called “physical” or “natural” evils, not because they are of the physical or material order, but because some good due to them according to their nature (in Greek, physis and in Latin, natura) is lacking. For a man not being able to fly is, in some sense, a lack, but it is certainly not evil since it does not belong to the nature of man to fly. To be upset about one’s inability to fly would be childish. Likewise, it is not evil for a rock not to be able to see. However, it would be evil in the physical sense for a bird not to be able to fly or for a girl not to be able to see. This is what is meant by physical evil: to lack the goods entailed in possessing a certain nature.

What, then, is moral evil? Moral evil is a specification of the general concept of physical evil, such that it applies not to anything with a nature, but to the will. The will, in a sense, has a nature, not in that it is a substance, but in that it has a set of properties that belong to it and characterize its actions. In man, the will is the rational appetite; its proper object is the good as presented to it by man’s reason. Thus, the various actions of the will, choosing and intending and the like, are all done with respect to some good that is apprehended by reason. When a man judges that eating a piece of food would be good for him to do here and now, he chooses to eat the food in question.

The will, however, does not incline towards goods at random, but rather in an ordered way. We do not choose everything that seems good to us every time it seems good, lest we be in a constant state of eating ice cream. Rather, we choose goods that seem good to us hic et nunc (here and now) in view of our overall good. Human action is therefore not only concerned with pursuing goods, but with doing so in the right way. The way in which we pursue goods is governed by a law given to us by God (CCC no. 1849). God’s law is not something imposed arbitrarily to constrain human behavior but is rather a gift of love that guides human action to make it to be truly good for man. According to the Psalmist, the law of God is freeing (Ps 119:45), illuminating (Ps 119:98-100), and delightful to follow (Ps 119:46). Consequently, it belongs to the nature of the will to act in accord with God’s law, such that not doing so is a moral evil, which both causes disorder in man and is an offense to God.

The Sinful Action

It is worth stating again that every time a human person acts, he does so in view of some good. This, in fact, is what it means for something to be good: to be “choice-worthy”. To do what one thinks is bad is to act irrationally. Even when we do something that we know to be bad, we choose it because there is something about it that attracts us, which is to say that we perceive it to be good. This is most obviously the case in good actions. We eat to nourish ourselves, to enjoy company, and to experience the pleasure of eating good food. We play sports to exercise our bodies, to have fun with our friends, and in hope of a victory. But when we sin, we seek something good in a disordered way. To fornicate, for example, is to seek pleasure, but in a way that does not respect the dictates of the virtuous perfection of human nature. Fornication is, at the very least, grossly irresponsible since, pleasurable as it may be, it involves a morally unfitting sexual act, with the added possibility of the birth of a child in unjust circumstances.

This brief analysis raises a topic that needs a little more explanation: the rich inner life of human beings. Our motives for our actions always run deeper than what appears to be the case on the surface. A girl’s choice to listen to a song by a particular boy band may have little to do with the quality of the music that the band produced and much more to do with the feeling of companionship that she feels with her friends, who all like the same band, or with the feeling of closeness with the lead singer, on whom she has a crush. If human choices were more superficial, then most of us would scour the internet for all of the music we could find and listen to as much of it as we could so that we could determine our musical taste and base our listening choices entirely on our judgment of the quality of the music in question. But it is rather the case that when I ask someone why he is doing such, there is always an answer that is, as it were, beneath the surface. Why did you get up this morning? To go to work. Why do you go to work? To make money. Why do you want to make money? To provide for my family. Why do you want to provide for your family? To be a good father.

This type of examination could be performed for any action and will result in a seemingly endless series of answers. Eventually, however, if the line of questioning is pursued long enough, the result will be that there is one thing, one reason—called the ‘ultimate end’—for which a person does everything that he does.{2} For the Christian, this fundamental reason is love for God, or charity, which is properly understood as friendship with God,{3} and without which we can do nothing good.{4} People can, however, set something other than God as their ultimate end. Sometimes, this is something truly good, but a lower good than the summum bonum (the highest good), such as the common good of one’s society. At other times, this is something bad, like money. Money, of course, is not something bad in itself, but it is a bad thing for it to be the ordering principle of one’s life. This is because man is a spiritual creature for whom the only truly good things— friendship, truth, and, ideally, love of God— are themselves spiritual. Material things, like food and money, are helpful for man, but making them the ultimate end around which one orders one’s life tends to disorder a man. Consider a man who lives for money. This love of money will affect all his relationships, business dealings, family life, and so on. If money is truly that for which he lives, then he will not really have friends. He will have people whom he is trying to exploit for money. Establishing one’s life around money therefore deprives one of what is truly good in life. Seeking something spiritual as one’s ultimate end is better, but nothing short of God will truly satisfy man since any good short of God Himself will be finite, and its riches will eventually be exhausted.

Original Sin

Sin is mysterious. When we sin, we do something that we know is bad. Why do we do this? Proximate causes are easy to find: temptations, unruly passions, poor behavioral examples. But why do these things exist? The ultimate answer lies in original sin. Original sin is not personal sin, which describes an individual person’s actions. Original sin most commonly describes the state in which all mankind finds itself at birth in the current order of things—deprived of original innocence and original justice, broken, disordered, and with inclinations to sin. It also describes the original sinful action, the fall of Adam and Eve, which led to us existing in such a state.

If sin is mysterious, the fall of Adam and Eve is even more so, since they were created in an upright state. Scripture makes it clear that all God created was created as good. It could not have been otherwise. God is the source of all being and goodness. To say that God created an evil creature would be to say that God created something that lacked something that was proper to it. This makes God out to be a bad or malicious designer. God can no more make a mistake in creating than a fire can cool down a room. Adam and Eve, the first human beings, were, therefore, good. That is, they were morally upright.

Scripture tells us more about the situation in which Adam and Eve found themselves. We learn what life was like for Adam and Eve in the second and third chapters of Genesis. Adam and Eve were naked and not ashamed, which means that they were not troubled by unruly passions, as we are. They were also immortal, which is clear since death was a punishment for their sin. Their life was free of toil and pain. They also had a special relationship with God, as he walked in the garden with them. Aquinas explains that these characteristics of their situation were due to their relationship with God. Although not defective, they were, like all creatures, incomplete.

Aquinas uses an apt metaphor to describe the situation of man as he would have been created without these gifts. Although glass is a nobler material than iron, a good carpenter chooses to make a saw out of iron, rather than out of glass, since iron is more apt for cutting wood.{5} Nevertheless, to extend Aquinas’s metaphor, iron rusts. A carpenter chooses to make a saw out of iron not because of iron’s tendency to rust, but in spite of it. A good carpenter will therefore choose to make a saw out of iron and then will take care of the iron to prevent it from rusting.

God does something similar with our bodies, making them out of matter that is suitable to be informed by a rational soul, despite its shortcomings. Like a good carpenter, God compensated Adam and Eve for the shortcomings of their natural constitution by providing them with praeternatural (praeter = beyond or outside of) gifts, each of which accounts for one of the special characteristics of prelapsarian man. Man in the garden was thus immortal and impassible; he would die no natural death, and he did not suffer disease or disorderly passions (see CCC no. 396-401).

These gifts were not owed to man, nor are they a part of human nature. They are added to human nature to help make up for its natural shortcomings. Furthermore, they were gratuitously given by God in keeping with his friendship with Adam and Eve. Adam and Eve benefited from these gifts as a result of their relationship with God, but Adam and Eve, in sinning, ruined their relationship with God and therefore lost these gifts. Without them, they were not only left subject to the deficiencies of their own nature but had incurred the guilt associated with committing the first sin.

Adam and Eve were our first parents; as such, they were blessed with an endowment — the praeternatural gifts — that could have been passed on to all subsequent generations. But in losing these gifts, they, being the first human beings, lost them for all humanity. To the modern mind, this seems unjust. Why must we all suffer for a sin that we did not commit? Such a perspective overlooks the solidarity that members of the human family have with each other. (This is expressed starkly in Deuteronomy 5:9, which says that when one member of the human family sins, others suffer.) Human children are born in a state of extreme dependence. They acquire not just food and clothing, but language and culture from their parents and from those around them. God places enormous trust in the whole human family—especially in parents—by placing the wellbeing of some in the hands of others. The positive side of this is that we are all bound together with respect to our salvation (see Lumen gentium, 9), but the flipside of this solidarity is that, when this responsibility is not used properly and people who are responsible for others neglect their duties, other people suffer. Thus, it happens in the natural state of affairs that a father who squanders his money leaves his children with no inheritance, or a woman who drinks too much alcohol while pregnant causes her child to have fetal alcohol syndrome. As parents of the whole human race, Adam and Eve were responsible for passing on all of those things that parents normally pass on to children. But in their case, their charge included their friendship with God and the praeternatural gifts that came with it. Falling out of God’s good graces meant losing those gifts, not only for themselves but for the whole human race.

As a result of the sin of Adam and Eve, human children are born such that they suffer from the loss of original innocence, which causes everyone to experience concupiscence, ignorance, and malice.{6} Concupiscence is the propensity to experience unruly desires. This is a common cause of sin: we frequently feel inclined to do something that we know we should not, but the desire to do the thing in question makes doing it seem good. Consequently, we are ignorant of what is truly good for us; our unruly passions cloud our intellects and make it hard to know what the right thing to do is. Acting in such ignorance and performing sinful acts habituates the will to incline away from what is truly good for us and toward other things. This habituation is called malice.

It is thus easy to see how man, in such a state, sins. Looked at by itself, sin seems irrational, nonsensical, and downright silly. But when the unruly passions that characterize postlapsarian human existence are accounted for, the frequency of sin becomes more understandable. What remains unclear, however, is how Adam and Eve sinned despite not suffering from such disorder. The basic answer is that they were tempted by the devil. The devil tempted them, and can tempt us, not by manipulating our minds, but by suggesting to our senses that something seems better than it is, or good in a way that it is not. By following the devil’s suggestion rather than their own proper judgment, Adam and Eve committed the first sin. Having lost for themselves and us the praeternatural gifts, they also gave us bad example. From these considerations the three traditional sources of sin are derived: the devil (through temptation), society (through example), and the self (through concupiscence).

Mortal Sin

Mortal sin is, most properly speaking, what sin is. Original sin and venial sin are only sin in qualified senses. The classical definition of sin as a word, action, or deed against the divine law is simply what a mortal sin is. The best way to understand mortal sin is to view it in terms of the relationship that it ruptures. A man who has the virtue of charity is in a state of friendship with God, which is simply what it means to have the virtue of charity: to love God above all things and all other things in God. A mortal sin is one that ruins this friendship; it is an action that makes it such that one is no longer friends with God.

Mortal sin is therefore analogous to other kinds of actions that can ruin other kinds of relationships. Adultery ruins a marriage. After such an act, a married couple cannot simply live as husband and wife. The wound caused by the infidelity needs to be healed first. After an act of betrayal, a soldier cannot be trusted to fight on behalf of his country anymore. He would need to undergo reparations to assure his superiors and comrades that he is trustworthy. The same dynamic is at play in a Christian’s relationship with God. A mortal sin is one that ruins one’s friendship with God, and to restore that friendship one needs to repent of one’s sin.

The question is: What kind of action ruins one’s friendship with God? The Catholic tradition has grouped such actions under the category of sins whose matter is “grave.” Furthermore, a mortal sin must be committed with full knowledge and complete consent to be considered mortal (CCC no. 1859). That is, a person who commits a gravely evil sin but who does so without being aware of its gravity or who was compelled to do so does not act in a properly voluntary way and so does not commit a mortal sin. Each of these three criteria — gravity, knowledge, and consent — will be examined below.

Gravity

The first characteristic of a mortal sin is that it is a grave sin; that is, it pertains to some serious matter.{7} Matter is what the sin is “about.” Theft is about taking something that does not belong to you, and the price of the thing stolen is directly proportionate to the gravity of the matter of this sin of theft. Serious sins are those that are said to have grave matter. Using the gravity of the matter of sin as a basis, sins can be grouped into three categories.{8}

Some sins always admit of grave matter and are said to be malum ex toto genere suo (evil from their whole species). Other sins are said to be malum ex genere suo, (evil from their species). The difference between these two categories is that the latter admits of degrees, but the former does not. A sin like theft, for example, can be more or less grave, depending on what was stolen, how much of it was stolen, and the person from whom it was stolen. The theft of two pennies from a rich man is a much lighter sin than the theft of a hundred dollars from a poor man. The gravity of sins that are malum ex genere suo can be reduced to such an extent that they lose their status as grave sins and become light sins, which makes them venial rather than mortal, even when they are committed deliberately. Other sins, however, do not admit of light matter, which is to say that they cannot be done in such a way that they do not cause a serious offence to God. Whenever they are done with knowledge and consent, they are mortal sins. Such a sin as this would be murder; one cannot commit a “light murder.” Finally, there are sins that are veniale ex genere suo (venial from their species) which, due to their nature, are never grave, and are therefore always venial. A good example of this is impatience, which can lead one to commit grave sins, but which is itself only an example of being less gracious with someone than one ought. This does not violate that person’s rights, but does fall short of ideal behavior.

How can one tell into which category a sin should be sorted? There are a few ways to do this. The first step is to determine whether a sin admits of grave matter. One way to do this is to look at the virtue of charity, which pertains to love of God and love of neighbor. Anything that is directly contrary to love of God Himself, such as blasphemy or sacrilege, would be a grave sin. Likewise, any sin directly contrary to love of a neighbor himself, such as murder, or that is against the preservation and order of society, such as adultery, would be grave. Relatedly, another way to determine whether a sin is grave is by checking it against the primary precepts of the natural law. These precepts concern what is essentially good for man, meaning that it is gravely evil for man to contravene them. Thus, according to the natural law, a man is to protect and preserve his life, which renders the sin of suicide grave. Furthermore, according to the natural law, man is supposed to promote the good of society, whence theft is a grave sin. Yet another way to identify a sin as grave is to appeal to Scripture, which sometimes describes certain sins as abominations or says that they exclude one from the kingdom of heaven. A helpful example can be found in Galatians 5:19-21. Finally, the tradition of the Church also identifies certain sins as grave, either in the form of a decree from the pope or an ecumenical council or else in the unanimous teaching of the Fathers and Doctors. This would apply, for example, to the violation of a fast.

Once it is determined that a sin admits of grave matter, the next question to ask is whether it can admit of light matter. Sins that are malum ex toto genere suo cannot. The easiest way to figure out whether a grave sin falls into this category is to look at the divisibility of its matter. It is impossible to commit half of a sin of blasphemy, or a quarter of a murder, or a bit of idolatry. Such sins, therefore, cannot admit of parvity of matter, which means that they are not grave sins that can become light by reason of their matter. The matter of other grave sins does admit of such divisibility. Two good examples are theft and lying. The gravity of the sin of theft is correlated to the amount that is stolen. The gravity of the sin of lying is related to the subject that is lied about. The evil of the sin of theft is found in the function of property, which is supposed to support a person’s livelihood. If a society is going to be well organized and flourishing, the people in the society must have a certain respect for the property of others. Some acts of theft, however, hardly disturb the fabric of a society at all, nor do they injure the one from whom something is taken. If, for example, a man needed to write something down and took a pen from his friend’s desk and failed to return it, this would, in most scenarios, not cause any harm to the friend. However, such an action is not ideal, as it does not accord well with the general respect that people should have for the property of others. Also, if such an act is committed with too much disregard for the property of others, it can lead to more grievous acts of theft. But this action itself does not cause harm to its victim and does not, therefore, properly count as an act of theft, and therefore not as a sin in an unqualified sense. Whence the theft of a small amount is venial due to parvity of matter.

The sin of lying is similar. One can lie about important matters, such as those that pertain to the truths of religion, or about things that are important for the conduct of one’s life in society. The evil of lying is, of course, its propensity to deceive. Whence, to perform an inherently deceptive act regarding a matter of such import would be a grave sin. However, lying can also be about inconsequential matters, such as when an uncle falsely reports the presence of a stain on his niece’s blouse to make her think that she had, despite her mother’s admonitions, spilled something on her clothing, after which she discovers, to her delight, that she had managed to keep her outfit clean. No one would characterize such an action as malicious, and it is certainly not mortally sinful. Nevertheless, we have to hold our communication in high esteem. Man, unlike the animals, is able not only to communicate his feelings, but to communicate truth. It is this ability of ours that makes the existence of every characteristically human institution—education, government, arts, etc.—possible. Consequently, such an avuncular lie, traditionally termed a “jocular lie,” is, not being malicious in the slightest, a venial sin. However, due to the high regard that we should have for our ability to communicate the truth to one another, this type of action should still be avoided, as it demonstrates an insufficient regard for the truth and can lead to graver sins.

Finally, there are those sins that are always light, since of their nature they do not include any grave disorder. These sins fall into two categories, those which are related to the virtues of temperance and fortitude (which govern the passions) and those that are related to the virtue of justice (which concerns one’s relationship to others). Such sins are said less to be contrary to these virtues and more to be discordant with them. For example, sins that fall into the first category (connected to temperance and fortitude) are contrary to one’s own good. For example, if one eats too much at a meal—not so much as to harm one’s health, but more than one generally ought to eat—this would not be an intemperate act in itself, but it would not be in full accord with the nature of temperance. One did not harm oneself, but one also did not behave in a way that made proper use of food as the thing which is used for nourishment. Regarding justice, any action that would be contrary to justice, (i.e., that would violate the rights of another), could certainly not count as a sin that is venial per se. But if a person grows impatient with someone else, it is easy to see how this passion would be unwelcome and ought to be suppressed or avoided. But it is also easy to acknowledge that merely feeling impatient with someone else is not a violation of that person’s rights. Consequently, impatience can be called venial per se since it is not directly contrary to the virtue of justice, but neither does it take full account of the respect that one person owes another. Additionally, since it can easily lead to more grievous acts, it should be avoided.

Knowledge

The first thing that a toddler says when scolded for wrongdoing is, “I didn’t know I couldn’t do that.” This, in the language of casuistry, which children implicitly adopt very quickly, is an appeal to ignorance. If a properly human act is one that is voluntary, and if the will is the rational appetite moving toward what the intellect apprehends as good, then ignorance of what is good renders an act not to be properly voluntary, and therefore not a properly human act. An act that is not properly human cannot be a sin. Thus, if a person is genuinely ignorant of the wrongdoing that he is committing, then he is morally innocent for the wrongdoing in question, no matter how grave the evil wrought by the action.

This is why the second criterion that must be met for a sin to be considered mortal is that it is done with “full knowledge” (CCC no. 1859). It is easy to misunderstand this term. It does not mean that a person has to have perfect knowledge of the moral law, all of its applications, and a perfect understanding of the nature of mortal sin and its destruction of a person’s orientation to God as final end. It simply means that a person knows all that he needs to know in order to perform a voluntary action. In the case of a sin, this knowledge pertains to two things: what kinds of actions are forbidden by the law and whether this action is one of them. Ignorance of the law can come about most commonly today among those who were not sufficiently well-educated in the requirements of the law, or whose absorption of norms from the ambient culture has distorted their understanding of it. For example, one who was never told that it was a requirement of ecclesiastical law to fast on Good Friday would not be guilty of breaking the fast. Likewise, one who confuses the cultural admonition to be tolerant of others with our Lord’s command to love one’s neighbor as oneself might be excused for thinking that the Gospel requires only compassion for sinners and not correction of them.

The second kind of knowledge concerns what a person is aware of in a given moment. A person’s perception can often be clouded by one thing or another. Most commonly, the cause of this cloudiness is a person’s emotions, or, in traditional language, passions. Someone, for example, who is in a fit of anger may say things rashly that, if the person were calmer, he would not have said. This is why people will commonly apologize after a fight by saying, “I did not mean to say that; I was angry.” Passions, in sum, can cause a person to have a distorted view of reality such that, while the person may know in general that a particular action ought not to be committed, the forbidden action may seem attractive at the time. Depending on the force of the cause of a person’s clouded intellect, this cloudiness can diminish the voluntariness with which an action is performed and thus lowers the moral quality of a human action, making meritorious actions to be less meritorious, and sins to be less grievous.

In order for a sin to be mortal, full advertence must be present. This means that the person committing the sin must be aware that it is gravely sinful and must be in possession of his reasoning faculties at the time when he commits it. If he is not in possession of them, then he must not be responsible for losing possession of them. If a person, for example, deliberately gets drunk, then he is responsible for what he does while drunk, even if he would not have acted the same way while sober. Full advertence does not, however, mean complete and total awareness of the evil of an action. If one man kills another, all that is needed for full advertence is knowledge that killing is gravely wrong and awareness that this act is killing and, therefore, gravely wrong.

Indeed, it can be difficult to tell in practice whether the criterion of full advertence has been met. The general advice of the confessors in the Catholic tradition is to say that if a person overall seems conscientious about avoiding sin,{9} seems afraid of committing sins, and in general tries to avoid those things that would cloud his intellect and to avoid near occasions of sin, then if there is doubt as to whether such a person committed a sin with full advertence, it can generally be presumed that he did not. If, on the other hand, a person seems lax, does not show concern for violating the law, and is not careful to avoid near occasions of sin, then it can be presumed in cases of doubt that such a person did meet the criterion of full advertence.

There are certain signs that can suggest a lack of full advertence. If a person, for example, is drowsy or half-asleep when he commits a particular sin, it can be presumed not to have been done with full advertence. The same applies to someone who is drunk, but whose drunkenness was not deliberate, as when a person drinks spiked punch without realizing its potency. If a person is subject to a vehement passion, as when a person is made angry by the realization of some news and is not culpable for entering such a state, any sins committed in this state may be presumed not to have been done with full advertence. The same would apply to anyone who suffers from an emotional pathology, such as chronic anxiety, over which the person has limited control. Other signs that a sin was committed without full advertence include the firm belief after having committed a sin that, if the person had thought about it more carefully, he would not have committed it.

Consent

Consent is the affective counterpart to knowledge. Ultimately, a sin cannot be a sin if it is not a voluntary human act. Since the will is the rational appetite, a person must first know that what he is doing is wrong before he can choose to do something wrong. Imperfect knowledge causes imperfect consent. However, even when perfect knowledge is present, there can be obstacles that prevent the will from being able to carry out an action freely. When full knowledge is present, but the will is impeded from acting freely, then whatever consent there may be to the sin is imperfect, and the sin in question is not committed mortally.

Consent can be rendered either externally or internally imperfect. An external cause of imperfect consent occurs when someone or something coerces an agent so as to render him unable to make a free choice. Such would be the case, for example, if a driver standing at a red light had someone break into his car, stick a gun to the back of his head, and tell him to drive. The driver does not know what the intentions of his assailant are—Is he running from a crime? Or is he chasing someone in order to commit a crime? — so the act of driving the car on behalf of the assailant cannot be considered perfectly voluntary. Whatever sin the man with the gun is committing, the driver is not guilty of it.

There can also be internal causes that render consent to be imperfectly voluntary. This happens when a person is not able to exercise his will because of an unruly passion. Note, however, that since all passions affect one’s ability to think and to choose somewhat, the mere fact that avoiding a sin is rendered difficult by an unruly passion is not a sufficient cause for rendering consent involuntary. Rather, it must be the case that the passion in question makes it impossible for the person to make a free choice, and it must also be the case that the person is not responsible for the arising of the passion in question. Nevertheless, such things as shock, latent habits of which one has repented and tried to overcome, sleepiness or grogginess (e.g., from medication), and other such things can render imperfect one’s consent to an action.{10}

As in the case of knowledge, it is easy to explain the distinction between perfect and imperfect consent as a theoretical matter, but it is practically impossible to determine when, in actual cases, full consent to a sin has been given or not. Some signs that consent may be imperfect include the following. If a person is generally afraid of committing mortal sins and taking pains to avoid near occasions of them, it can generally be assumed that, in cases of doubt, he has not given full consent to the sin. Likewise, if a person experiences a desire to commit a sin and is able to restrain his external actions from giving into the full extent of the desire, he has not fully consented to it. Similarly, a person who experiences temptation and is saddened by this and makes an effort to overcome the temptation is likely not to have given full consent. Finally, if a person who is groggy or otherwise not in full possession of his faculties commits a sin that, later on and with a clear head, he feels confident that he would not have committed if he were in a better state of mind, he can be presumed not to have given full consent to the sin. On the other hand, as in the case of knowledge, a person who is generally lax and does not take pains to avoid near occasions of sin ought to be presumed, in cases of doubt, to have given full consent to the sins in question.

Venial Sin

Sins that do not meet all three of the qualifications above (that is, that fail to meet any one of these three criteria) are considered venial. This word comes from the Latin word venialis, which means “pardonable.” The reason for this designation is that one who commits a venial sin can simply ask God to be forgiven for having committed it.{11} Regarding the sacrament of confession, venial sins may, but do not need, to be confessed. Part of the reason for this is that it would be practically impossible to confess every venial sin that one was aware of committing. Even the just man sins seven times a day (Prv 24:16). The theological reason why venial sins do not need to be confessed is that they do not destroy the theological virtue of charity, the restoration of which is the purpose of the sacrament of confession. A venial sin then, as it falls short of the ratio of sin, is not, properly speaking, a sin. What, then, is it? Why do we have this category? What should we make of it?

It is important to note from the outset that the distinction between mortal and venial sin has grounding in both Scripture and reason. Scripture, first of all, makes it clear that some sins are graver than others, as when our Lord criticizes the Pharisees for “straining out a gnat and swallowing a camel” (Mt 23:24), or when He makes the comparison between specks and beams that may be lodged in one’s eye (Lk 6:42). While, indeed, some sins can be greater than others, the question remains as to whether there is a qualitative difference between light and grave sins, or whether there is merely a spectrum from less to more evil. There are a few Scriptural passages that imply that some sins differ from others in kind and not merely in degree. Qoheleth asks whether there is a “righteous man on earth who does good and never sins” (Eccl 7:20) and Proverbs tells us that even the righteous man “falls seven times a day” (Prv 24:16). If righteousness is incompatible with sinfulness, then how is it possible that a man can both be just and a sinner? The answer is that the sins in question are not mortal sins, as venial sins can be committed by a just man who can nevertheless remain just.{12} Finally, it is worth noting that Catholic moralists have traditionally cited the distinction between mortal and venial sins in 1 John 5:16-17,{13} where St. John says that there is sin that is deadly and sin that is not deadly.

This distinction is not only present in Scripture, but also makes sense rationally. A helpful example (taken from ST I-II, q. 88, a. 1) comes from our own bodily life. Charity is the principle of our life as Christians. Venial sins are merely harmful to that principle while mortal sins are deadly to it. In the case of bodily life, our health is the principle of our vital actions, which is harmed by sickness. Just as there is a difference between sickness and death, or between unhealthy food that harms our health and poison that destroys it, so there is a difference between the actions which can harm our supernatural relationship with God and those that can destroy it. This distinction also makes sense in view of the nature of charity, which is a friendship. In our earthly friendships, there are some actions that can destroy a friendship, such as betrayal, and other actions that harm a friendship but do not destroy it, such as telling an embarrassing story about one’s friend. Analogously, this consideration can be applied to charity with God: there are some actions, such as blasphemy, that are simply incompatible with having a friendship with God, and other things that displease God but do not destroy one’s relationship with him. Furthermore, though we can bring ourselves back to health from sickness, we cannot bring ourselves back to life from death. We can pray to be forgiven for our venial sins, but we cannot place ourselves back into God’s friendship by our own efforts. This requires God’s initiative and is normally accomplished through the sacrament of confession.

Although venial sins do not destroy the relationship that one has with God, they still ought to be avoided, much as one ought to avoid injuring an earthly friendship with a friend. One who engages in actions that harm but do not destroy a friendship will eventually find his friendship destroyed. This is the primary reason for avoiding venial sins: they lead to mortal sins. Man is, after all, a creature of habit. Acting on a disordered inclination toward a mutable good will incline one to do so again. Thus, while one wants to avoid scrupulosity, one should also not adopt too casual an attitude toward venial sins, or else it becomes easy to find oneself committing mortal sins. Moreover, venial sins, following the analogy with health above, are unhealthy for the spiritual life, which in this case means that they inhibit the exercise of charity and the grace of God from achieving their full effect. Just as a sick man cannot perform an athletic task as well as a healthy man, so a man whose soul is suffering from the effects of venial sin cannot perform an act of charity with as much fervor as one whose soul is not so affected. The spiritual life is like the biological life in that it does not stagnate; it either grows or dies. Thus, one always wants to do whatever promotes growth. Finally, although venial sin does not incur the punishment of eternal death, it nevertheless does incur temporal punishment and afflicts the soul with a certain degree of disorder. A person who dies with many venial sins on his heart will have to suffer more in Purgatory than one who does not. In short, even though they are not mortal, one should avoid committing venial sins as much as one can.

Causes of Sin

If sin is to be avoided, the most helpful thing to know is what causes it. These causes can be divided into two categories: interior and exterior. The interior causes of sin are the faculties of the soul that are implicated in a sinful act: the intellect, the will, and the powers by which we imagine and experience passions.{14} The exterior causes of sin are the devil and his demons, the world, and, as broad as this category is, any external good. Of course, one of the things that is not included in the list of causes is God. Although God is the cause of all things, he causes all things only insofar as they are, which is also to say insofar as they are good. A sin is an act that is characterized by a certain privation. This privation is allowed by God but not caused by Him.

As for the Devil and demonic temptation, it is important to note the limits of what malicious spirits can do. The Devil is not a direct or sufficient cause of sin; man’s will must play a role as well. Since the intellect and will are spiritual faculties, no created being can act upon them directly. Consequently, the Devil cannot make anyone think that something is good when it is not, nor can he incline anyone’s will toward anything at all. All the Devil can do is propose or suggest something to the sensitive appetite or imagination, which, being material, can be affected by other agents. As such, the Devil can make a perceived object seem good, that is, he can suggest that it is attractive and can even cause a person to feel attracted to it, but the choice of whether to pursue it or to make a judgment about its goodness remains in the power of the person tempted. This activity of the Devil is called “suggestion,” and that is all that it is. As with any other suggestion, a person is always free to disregard it.

Ourselves and the things we encounter in the world can also be causes of sin. Due to the corruption of our nature (i.e., original sin), which we inherit from our first parents, our reason has imperfect control over our emotional life, which causes our passions sometimes to incline to illicit things. This tendency of the sensitive appetite to make us feel attracted to goods that we should not pursue is called concupiscence, but it has gone by many names over the years, including “fomes peccati,” (see CCC no. 1264) or the “tinder of sin.” Given the imperfect control that we have over our sensitive appetite, it sometimes happens that we feel inclined to pursue some good in the world in a disordered way, such as when a man feels inclined to have sexual relations with a woman who is not his wife. As in the case with demonic temptations, such occurrences amount to suggestions, which can be disregarded.

It is important to note that, while consenting to a temptation is a sin, to feel a temptation is not a sin. The reason for this is clear from the logic above about the human act. No act is considered a human act unless it is deliberate and voluntary. A person who undergoes temptation does not choose to do so. If he does, that is another matter. The moral problem is analogous to a case where one person suggests a sin to another, which no one would account a sin on the part of the listener. But, to continue the analogy, one should avoid engaging with people who would do such a thing. Likewise, although no one is responsible in se for experiencing a temptation, one should avoid things that cause temptation (near occasions of sin), and one should avoid causing others to fall into sin.

Remedies and Reparation for Sin

The term “remedies for sin” refers to those means by which a person can avoid sins, overcome sinful inclinations, and recover from the effects of sin. The first and most important thing a person must do is be vigilant. St. Peter exhorts as much (1 Pt 5:8), and this exhortation is repeated in the Roman Office every Tuesday night at compline.{15} Likewise, our Lord admonishes his disciples: “Watch and pray that you may not enter into temptation” (Mt 26:41). Vigilance expresses humility; it is a recognition of our finite and wounded status and an acknowledgement of our need for help. This humility should incline us to place our trust in God, who “gives grace to the humble” (Jas 4:6), and to pray fervently for this grace, which Christ taught us to do in the Lord’s Prayer (Mt 6:13 and Lk 11:4), and which should include frequent use of the sacraments. In the case of those who are struggling to overcome a particular sin, spiritual direction may be in order. Since the human heart is “deceitful above all things” (Jer 17:9), it is easy to be in a state of denial about the seriousness of one’s own need for grace and the need to overcome sinful habits. A spiritual director can help one to have a sober and accurate view of one’s own state.

Despite making use of these remedies, everyone who has ever walked the earth—excepting Jesus and his Mother—has sinned. To say otherwise is to deceive oneself (1 Jn 1:8). Other than the effects of sin that were discussed above—that it introduces disorder into the soul and that it ruptures or destroys one’s relationships with God or others—another effect of sin is that it incurs guilt and punishment, which themselves can be a kind of remedy for sin. The natural effect of sin, the disorder that it causes in the soul and the damage or destruction done to the relationship with God, is called the malum culpae (the evil of guilt or fault), which makes one due to receive the malum poenae (the evil of punishment).

Having sinned, one is then owed punishment, which is the natural reaction to sin. Even in biological systems, when disorder is introduced, order is quickly reestablished. Human societies, both the state and the Church, are no different. When, for example, a man steals from another man, he causes a certain disorder to exist in his society. In essence, the thief sets himself apart from the law, making himself into a quasi-lawgiver rather than a subject of the law. The response of a society is to set this disorder aright through punishment. The thief must not only restore what he stole (reparation), but he must also suffer punishment, which re-subjects him to the law. Since it is good for man to live in society, punishment is good for man in three ways. The threat of punishment, or the sight of someone being punished, deters others from committing the same crime, which is why laws are issued with punishments prescribed for those who break them. Punishment also, as previously explained, suppresses those who exalt themselves above the law and places them back in line with the law, thus restoring them to their place in society. Finally, punishment restores order to the soul. When a man commits a crime, he acts out of a disordered desire, but punishment can have the effect of making the crime seem less desirable, and if it does, then the man’s soul is restored to a more ordered state by the punishment.

In the case of one’s supernatural life, the punishment owed for mortal sin is eternal damnation, that is, separation from God. This is clear from Scripture, as when our Lord condemns to eternal fire those who did not give the hungry food or the thirsty drink (Mt 25:41, 46), wherein those who are damned suffer torment forever (Rev 14:11). This is, of course, also affirmed in the Tradition of the Church and is stated quite clearly in the Council of Florence, which says: “As for the souls of those who die in actual mortal sin or with original sin only, they go down immediately to hell, to be punished.”{16}

The fact that mortal sin incurs eternal damnation also follows rationally from much of what has been said above. It is often presumed today, even by many Catholics, that hell either does not exist or is empty, or perhaps it exists and is populated, but only by those who committed the most heinous crimes in world history. This position neglects to consider the reality of original sin, according to which man is born into a state of estrangement from which he needs to be rescued. That is, it is not the case that man is destined for heaven by default and only fails to make it there if perhaps he commits some extremely grave sin. Rather, it is the case that man is born into a state of estrangement from God, such that he stands in need of a Savior. When he is so saved, by the merits of Christ and through the waters of Baptism and, after falling, is restored through the Sacrament of Reconciliation, he is placed into a state of grace, such that he has the theological virtue of charity, which is, in its essence, friendship with God. Mortal sins destroy this friendship, and man cannot reestablish this friendship; this initiative belongs to God. Consequently, the natural and necessary result of committing a mortal sin is that one is no longer in a state of friendship with God, and if this state were to persist to the point of death without God’s having made any intervention, then it would become permanent.{17} While drawing this conclusion often causes no small degree of consternation, it should be kept in mind that God truly desires all men to be saved (1 Tm 2:4), and it is therefore the teaching of the Church that God makes it truly possible for each and every human person that he be saved.{18} It is also worth noting that a plea to God’s mercy can be seen in the medieval doctrine of limbo, which described the fate of infants who died before they were baptized. Not being baptized, they died in a state of original sin, but not having use of their reason, they did not commit any personal faults. Consequently, many throughout Church history have thought that such souls lived in a state of estrangement from God (which was, technically, hell), but was devoid of any other kind of punishment, and so was not hell in the sense in which many understand the term today. So, while we should not be too presumptuous upon God’s mercy and neglect the reality of hell, neither should we fall into a state of despair, keeping in mind that God is the most just and the most merciful of judges.

Venial sin, in the case of one who is baptized, does not incur eternal punishment, and this is because it does not destroy the virtue of charity in the soul. Nevertheless, because of the disorder that it introduces into the soul, those who die with venial sins on their heart must undergo some temporal punishment to remedy this disorder before they can see God “face to face.” This is the justification for the Catholic doctrine of purgatory, which is a state through which those souls that die in a state of grace but affected by venial sins must pass before they move on to the eternal beatitude of heaven. In order to avoid such a fate, it should be noted that not only are there copious opportunities to be forgiven of venial sins, but that it is also possible to remit the punishments due for venial sin and thereby avoid time in Purgatory by performing acts of penance or by obtaining indulgences.