Intro Truths
Scripture Saints
Culture Worship

Moral Evil

These notes are derived from Catholic Morality by Fr. John Laux.
Section I, Chapter III: Moral Evil, pp 40-50.
The chapter 'On Sin and its Kinds' from the Baltimore Catechism
covers similar material and is included below.

Nature of Sin

Sin — Any willful thought, desire, word, action or omission forbidden by the law of God.

Sin is evil in light of reason because:

  • It degrades our nature and gives us a sense of shame
  • Causes injury to our fellow man or to ourselves
  • It disturbs God's moral order

Sin is evil in light of faith because:

  • It is a rebellion against God's will, showing ingratitude
  • It is a rejection of Christs gift
  • It is makes us the slave of sin, gives away our freedom to do gods will
  • It Separates us from God

Vice is persistent immoral behavior that is ingrained by bad habits or repeatedly engaging in bad actions. A single bad action does not constitute Vice

Kinds of Sin

  • Original Sin — State of separation from God inherited from our the sin of our first parents.
  • Actual Sin — Refers to a personal act of sin, either mortal or venial.
  • Mortal Sin — Complete separation from God brought about by intentional acts of disobedience to God's will. Mortal sins destroy sanctifying grace.
  • Venial Sin — Willful deviation from the path of righteousness and weakening of Grace. Venial sins weaken the will but don't destroy sanctifying grace.
  • Sin of Omission — Failure to do something one can, and ought to do. Sin occurs in case of knowledgeable and willful omission.
  • Near occasion of sin — These are all persons, places, or things that may lead us into sin. Near occasions of sin are not actual sin as long as temptation is resisted.
  • Capital Sin — A group of vices, known as 'Seven Deadly Sins' that result in sinful behavior. Capital sins are Pride, Greed, Lust, Envy, Gluttony, Wrath, and Sloth.

Mortal sin involves

  • Grave matter (object)
  • Done with full knowledge of sinfulness (circumstance)
  • With full consent of will (intention)

Sins differ in gravity and seriousness. Intention and circumstance effect severity.

  • Sins against God (Blasphemy, Apostasy) are greater than Sins of impurity or theft.
  • Venial sins can be deliberate or indeliberate.
  • Malice of the will results in Mortal sin
  • Weakness of the will results in Venial sin


Temptation is the incitement to choose personal satisfaction in place of the will of God. Temptation is a trial but it is not sin. Prepare to meet Temptation by:

  • Prayer
  • Deliberate acts of self-denial
  • Turning our minds away from object of temptation
  • Resist temptation at first incitement
  • Fix mind on love of Christ
  • Avoid near occasions of sin

Love of God is a better motivation that fear of God, but Fear of God is sufficient motivation to resist temptation and avoid sin.

Glossary of Moral Teaching Terms

  • Culpability — Measure of the degree to which a person hand be held morally or legally responsible for an act.
  • Malice — Intention or desire to do evil, or cause injury or distress to another.
  • Reparation — Repair of some spiritual or material damage done to a person.
  • Temporal punishment — Punishment due to our sins which we are obliged to endure for a time, either in this life or in purgatory.

On Sin and Its Kinds

Q. 274. How is sin divided?

A. (1) Sin is divided into the sin we inherit called original sin, and the sin we commit ourselves, called actual sin. (2) Actual sin is sub-divided into greater sins, called mortal, and lesser sins, called venial.

Q. 275. In how many ways may actual sin be committed?

A. Actual sin may be committed in two ways: namely, by wilfully doing things forbidden, or by wilfully neglecting things commanded.

Q. 276. What is our sin called when we neglect things commanded?

A. When we neglect things commanded our sin is called a sin of omission. Such sins as wilfully neglecting to hear Mass on Sundays, or neglecting to go to Confession at least once a year, are sins of omission.

Q. 277. Is original sin the only kind of sin?

A. Original sin is not the only kind of sin; there is another kind of sin, which we commit ourselves, called actual sin.

Q. 278. What is actual sin?

A. Actual sin is any wilful thought, word, deed, or omission contrary to the law of God.

Q. 279. How many kinds of actual sin are there?

A. There are two kinds of actual sin—mortal and venial.

Q. 280. What is mortal sin?

A. Mortal sin is a grievous offense against the law of God.

Q. 281. Why is this sin called mortal?

A. This sin is called mortal because it deprives us of spiritual life, which is sanctifying grace, and brings everlasting death and damnation on the soul.

Q. 282. How many things are necessary to make a sin mortal?

A. To make a sin mortal, three things are necessary: a grievous matter, sufficient reflection, and full consent of the will.

Q. 283. What do we mean by "grievous matter" with regard to sin?

A. By "grievous matter" with regard to sin we mean that the thought, word or deed by which mortal sin is committed must be either very bad in itself or severely prohibited, and therefore sufficient to make a mortal sin if we deliberately yield to it.

Q. 284. What does "sufficient reflection and full consent of the will" mean?

A. "Sufficient reflection" means that we must know the thought, word or deed to be sinful at the time we are guilty of it; and "full consent of the will" means that we must fully and wilfully yield to it.

Q. 285. What are sins committed without reflection or consent called?

A. Sins committed without reflection or consent are called material sins; that is, they would be formal or real sins if we knew their sinfulness at the time we committed them. Thus to eat flesh meat on a day of abstinence without knowing it to be a day of abstinence or without thinking of the prohibition, would be a material sin.

Q. 286. Do past material sins become real sins as soon as we discover their sinfulness?

A. Past material sins do not become real sins as soon as we discover their sinfulness, unless we again repeat them with full knowledge and consent.

Q. 287. How can we know what sins are considered mortal?

A. We can know what sins are considered mortal from Holy Scripture; from the teaching of the Church, and from the writings of the Fathers and Doctors of the Church.

Q. 288. Why is it wrong to judge others guilty of sin?

A. It is wrong to judge others guilty of sin because we cannot know for certain that their sinful act was committed with sufficient reflection and full consent of the will.

Q. 289. What sin does he commit who without sufficient reason believes another guilty of sin?

A. He who without sufficient reason believes another guilty of sin commits a sin of rash judgment.

Q. 290. What is venial sin?

A. Venial sin is a slight offense against the law of God in matters of less importance, or in matters of great importance it is an offense committed without sufficient reflection or full consent of the will.

Q. 291. Can we always distinguish venial from mortal sin?

A. We cannot always distinguish venial from mortal sin, and in such cases we must leave the decision to our confessor.

Q. 292. Can slight offenses ever become mortal sins?

A. Slight offenses can become mortal sins if we commit them through defiant contempt for God or His law; and also when they are followed by very evil consequences, which we foresee in committing them.

Q. 293. Which are the effects of venial sin?

A. The effects of venial sin are the lessening of the love of God in our heart, the making us less worthy of His help, and the weakening of the power to resist mortal sin.

Q. 294. How can we know a thought, word or deed to be sinful?

A. We can know a thought, word or deed to be sinful if it, or the neglect of it, is forbidden by any law of God or of His Church, or if it is opposed to any supernatural virtue.