A depiction of Cerberus - the three-headed dog monster - who in Dante’s Inferno guards the third circle of hell - the gluttons.

Listers after an excellent discourse on why gluttony is a sin in article one, the Angelic Doctor discusses whether or not gluttony is a mortal sin. The Baltimore Catechism states a “mortal sin is a grievous offense against the law of God.” The catechism continues: “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.”1 Gluttony is a sin because it is an inordinate desire towards food and drink and we say “inordinate” because it is outside the scope of reason. Actions within the order of reason are virtues; thus, an action outside the order of reason is a vice or sin. Aquinas’ question is whether it is a mortal sin?

Article Two Whether gluttony is a mortal sin?

How to Read the Summa Theologica Aquinas’ structure of the Summa Theologica is unique to our modern customs. The Common Doctor proposes a question and in this case it is Whether gluttony is a mortal sin? He then provides a few – in this case four – arguments that he believes to be false answers. He will then present a sed contra or a “On the contrary” statement which is a summary or the principal point of answering the question correctly. Immediately following the sed contra, the saint will give the main body of his answer and then handle each of the incorrect answers individually. It should be noted that the Summa is not an encyclopedia, but rationally ordered development of questions that building upon one another.

Below the entirety of St. Thomas’ second article on gluttony is presented. SPL has added the titles, their numbers, and the footnotes for clarification.

The four incorrect position St. Thomas will refute below.

1. Not contrary to the Decalogue

Objection 1. It would seem that gluttony is not a mortal sin. For every mortal sin is contrary to a precept of the Decalogue: and this, apparently, does not apply to gluttony. Therefore gluttony is not a mortal sin.

2. Not contrary to Charity

Objection 2. Further, every mortal sin is contrary to charity, as stated above (Question 132, Article 3). But gluttony is not opposed to charity, neither as regards the love of God, nor as regards the love of one’s neighbor. Therefore gluttony is never a mortal sin.

3. Augustine: A “lesser sin”

Objection 3. Further, Augustine says in a sermon on Purgatory [Cf. Append. to St. Augustine’s works: Serm. civ (xli, de sanctis)]: “Whenever a man takes more meat and drink than is necessary, he should know that this is one of the lesser sins.” But this pertains to gluttony. Therefore gluttony is accounted among the lesser, that is to say venial, sins.

4. Gluttony is a mortal sin

Objection 4. On the contrary, Gregory says (Moral. xxx, 18): “As long as the vice of gluttony has a hold on a man, all that he has done valiantly is forfeited by him: and as long as the belly is unrestrained, all virtue comes to naught.” But virtue is not done away save by mortal sin. Therefore gluttony is a mortal sin.2


St. Thomas Aquinas responds to the four above incorrect answers on gluttony as a mortal sin.

5. Gluttony in respect to man’s end

I answer that, As stated above (Article 1), the vice of gluttony properly consists in inordinate concupiscence. Now the order of reason in regulating the concupiscence may be considered from two points of view. First, with regard to things directed to the end, inasmuch as they may be incommensurate and consequently improportionate to the end; secondly, with regard to the end itself, inasmuch as concupiscence turns man away from his due end.3

Accordingly, if the inordinate concupiscence in gluttony be found to turn man away from the last end, gluttony will be a mortal sin. This is the case when he adheres to the pleasure of gluttony as his end, for the sake of which he contemns God, being ready to disobey God’s commandments, in order to obtain those pleasures. On the other hand, if the inordinate concupiscence in the vice of gluttony be found to affect only such things as are directed to the end, for instance when a man has too great a desire for the pleasures of the palate, yet would not for their sake do anything contrary to God’s law, it is a venial sin.

6. Decalogue pertains to justice

Reply to Objection 1. The vice of gluttony becomes a mortal sin by turning man away from his last end: and accordingly, by a kind of reduction, it is opposed to the precept of hallowing the sabbath, which commands us to rest in our last end. For mortal sins are not all directly opposed to the precepts of the Decalogue, but only those which contain injustice: because the precepts of the Decalogue pertain specially to justice and its parts, as stated above (Question 122, Article 1).

7. Contrary to Charity

Reply to Objection 2. In so far as it turns man away from his last end, gluttony is opposed to the love of God, who is to be loved, as our last end, above all things: and only in this respect is gluttony a mortal sin.

8. St. Augustine commenting on the venial

Reply to Objection 3. This saying of Augustine refers to gluttony as denoting inordinate concupiscence merely in regard of things directed to the end.4

9. Vices which arise from gluttony

Reply to Objection 4. Gluttony is said to bring virtue to naught, not so much on its own account, as on account of the vices which arise from it. For Gregory says (Pastor. iii, 19): “When the belly is distended by gluttony, the virtues of the soul are destroyed by lust.”


Lists St. Thomas Aquinas

Patrimony of Wisdom: St. Pius X’s Exhortation to study Aquinas The Sun that Warms the World – St. Thomas Aquinas What Vatican II Actually Said About St. Thomas Aquinas The 3 Part Catechesis on St. Thomas Aquinas by Pope Benedict XVI All lists tagged Aquinas and all tagged Summa Theologica.


  1. SOURCE: Baltimore Catechism No. 3 Lesson 6 - On Sins and Its Kinds ↩︎

  2. Objection and Contrary? - The question on whether gluttony is a mortal sin displays a rare occurance where the last objection also is the “sed contra” or on the contrary. This means the given opinion is contrary to the above false answers, but is itself false or incomplete. In this case it appears that St. Gregory’s comment is being used to say gluttony is only a mortal sin - while Aquinas demonstrates gluttony can be either venial or mortal. ↩︎

  3. What is the “End of Man”? - “By the “end of man” we mean the purpose for which he was created: namely, to know, love, and serve God.” ↩︎

  4. Augustine: The quote of Augustine is referring to venial sins (cf. Aquinas’ first way of an act being incompatible with man’s end), but the fact an act can be venial does not negate the potential for it to become mortal. ↩︎