Thomas Aquinas
Treatise on Virtues: A Brief Summary

based on John A. Oesterle's translation
University of Notre Dame Press, 1984

Compiled by Dr. Jan Garrett
Last revised September 13, 2005

Q. 49. Habits in General

(49a1) A habit (or disposition) is a quality.

Quality is one of the ten basic groups of things listed by Aristotle in his Categories. Qualities always presuppose some subject of which they are qualities and in which they inhere. (For instance, baldness as a quality inheres in the body of Socrates, so that one can truly say that Socrates is bald.)

Because habit is a quality, it is an accident of the subject in which it inheres. Accidents (without further qualification) do not attach to their subjects with necessity. Socrates might not be bald.

(49a2) A habit is a quality by which one is well or ill disposed; being well or ill disposed relates to the perfection of a thing's nature.

(49a3) A habit implies ordered toward act (i.e., toward second act, insofar as a habit is a first act). A habit is related essentially to the nature of a thing, but the nature of a thing does not determine that it will have the habit.

(49a4) Habits are necessary if there are to be perfections of beings that can be determined in various ways.

Habits are dispositions of some subject which is in potentiality in regard to something, either in regard to a thing's nature or to its operation, which is the end of its nature. (see 54a1) DEFINITION of habit?

Q. 50 The Subject of Habits

(50a1) There are habits of the body, health as a long-standing disposition of the body, for instance, and strength.

(50a2) Habits in the soul are in its powers, not in the essence of the soul; but there is an exception, grace (50a2R),

(50a3) Sense powers operating from natural instinct contain no habits, but they do as operating at the command of reason. (a3)

(50a4) There is habit in the intellect, e.g., wisdom, science, and understanding.

(50a5) There is also habit in the will: justice, by which one wills and does what is just. Thomas cites NE 5.1.1129a7. Will is rational appetite and appetite is a power.

(50a6) There are habits in the angels, because they are wise but are not essentially in [2nd] act, because only God is in act in this way. An angel has a well-disposed intellectual habit.

Q. 51 The Cause of the Formation of Habits

(51a1) Some habits are from nature

(51a2) Some very important habits are caused by acts. Humans contain active and passive principles-the will is an active principle and the appetitive powers are passive principles. Habits are caused in appetitive powers when they are moved by reason.

(51a3) A habit cannot be produced in an appetitive power in one act. A habit of moral virtue therefore cannot be produced that way. But a scientific habit can be produced by a single act of reason so far as the possible intellect is concerned.

(51a4) Some habits are infused in human beings by God, e.g., saintly dispositions "exceeding the power of human nature."

Q. 52 The Increase of Habits

(52a1) Habits can increase. With respect to a form, e.g., health, a thing can participate in it more or less. But "if any form . . . takes on the notion of species it must have a determinate nature and can be neither more nor less."

(52a2) Habits increase not through addition but through greater participation of the subject in the habit.

(52a3) Not every act increases a habit. If the act is contrary to the habit or of lesser intensity than is require to build the habit, the act may decrease the habit. A person who was becoming truthful, if he takes up lying, will decrease his truthfulness. A person who was becoming strong, if he gives up vigorous exercise, will become weaker.

Q. 53 Corruption and Diminishing of Habits

(53a1) Habits can be corrupted, e.g., spurious reasoning can corrupt true opinion, or even science, virtues and vices by judgments of reason that move contrary to those moral habits.

(53a2) Habits can be diminished.

(53a3) Habits can be corrupted or diminished by mere cessation of the corresponding acts. (Use it or lose it!)

Q. 54 The Distinction of Habits

(54a1) Multiple habits can be in the same power, "inasmuch as the parts of one subject can be considered in various ways." Thus intellect can contain art, science, and understanding, and even several arts (dialectic, medicine, etc.) or sciences (geometry, astronomy, etc.)

(54a2) Habits are distinguished by their objects; sciences are distinguished by, e.g., whether their objects are, e.g., number (mathematics) or the set of visible things that change (physics).

Thomas adds that habits may be distinguished in terms of three things: (1) the active principles of such dispositions; (2) in terms of the nature; (3) in terms of objects that differ specifically.

(54a3) Habits are distinguished specifically as to whether they are good or evil. I think this is what Thomas meant when he said habits are distinguished in terms of the nature.

(54a4) A habit that is ordered to operation is a form-as such it does not consist of many things. It is a perfection of some power. (A habit, such as knowledge, can be extended from fewer things to a greater number; that is not ruled out. In describing the aspects of a virtue, several things may be noted, but these "parts" are not integral parts but potential or subjective: only in the complete virtue do they come into their own.)

Q. 55 The Essence of Virtue

(55a1) Human habits, which are perfections of rational powers, are virtues.

(55a2) Human virtue is an operative habit, i.e., a habit ordered to act (rather than mere being).

(55a3) Human virtue is a good habit and productive of good works.

(55a4) Lombard's definition of infused virtue, "virtue is a good quality of the mind, by which we live rightly, of which no one can make bad use, which God works in us without us" is a flawless definition because it comprises all the causes of virtue:

(1) formal: good quality,
(2) matter in which: the mind;
(3) final cause: operation (=use);
(4) efficient cause (God).
Thomas says that the general definition of virtue would emerge if the only first three items were stated.

Q.56 The Subject of Virtue

(56a1) The powers of the soul are subjects of virtue, i.e., things in which virtues can inhere.

(56a2) One virtue cannot be in multiple parts equally, although it can be in one principally and others when they are moved by the principal power and receive direction from it.

(56a3) The intellect is the subject of certain virtues, e.g., art, knowledge, prudence. Of these virtues, some make a person good in a qualified sense; scientific knowledge, e.g., makes a person good as, e.g., a mathematician; art makes a person good as, e.g., a medical doctor.

In the case of prudence, intellect is moved by the will; the will also moves the passions (in temperate and brave acts, for instance). Prudence, along with justice, temperance, and fortitude, are virtue unqualifiedly. So is generosity, I think.

(56a4) The irascible and concupiscible powers "as participating in reason," i.e., shaped by it, are subjects of fortitude and temperance, respectively.

(56a5) The sense powers of knowing (specifically memory) are not subjects of virtue. Thomas' reasoning: (1) all moral virtues are in the appetitive part of the soul-this leaves goodness of memory out; (2) the virtues are perfect habits but a good memory is either not a habit or not a perfect habit related to knowing. One can have a good memory but lack knowledge (in the sense of fully articulated science).

Q. 57 The Distinction of the Intellectual Virtues

(57a1) "Speculative intellectual habits may be virtues insofar as they confer an aptitude for good operation, namely, for considering truth."

(57a2) There are many sciences, only one wisdom (the science that concerns itself with the highest causes), and understanding of principles "at once."

(57a3) Art is right reasoning about certain works to be made. It has the nature of virtue in the same way as speculative virtues, i.e., it is an intellectual virtue.

(57a4) Prudence, defined as right reason about what is to be done, is a virtue distinct from art.

(57a5) Prudence is a virtue most necessary for leading the good life. Truth in the practical intellect depends on conformity with right appetite (a virtuous will and morally trained passions). (r3)

(57a6) Good deliberation, sagacity, and equitable judgment are added to (aspects of?) prudence.

There are three acts of reason regarding actions done by humans: deliberation, judgment, and command.

(1)Deliberation and judgment correspond to acts of the speculative intellect, inquiry and judgment [but here they are in the practical intellect?]
(2) Command is proper to the practical intellect insofar as it is productive of a command.
At this point subordinate virtues of sagacity and equitable judgment are invoked: Sagacity judges of actions according to the common law, equitable judgment is based on natural reason and applies to cases where common law fails to apply. (r.3)

Q. 58 The Distinction Between Moral and Intellectual Virtues

(58a1) Not all virtues are moral virtues; only those in the appetitive powers (will and sense appetites).

(58a2) Moral virtues differ from intellectual virtues. Intellectual virtues dispose a man's reason well, while moral virtues make desire follow reason.

(58a3) The division of virtue into intellectual and moral is adequate, since there are two principles of human action in (the intellect and the appetite), and every human virtue must perfect one of these.

(58a4) Moral virtue cannot exist without the intellectual virtues of prudence and understanding, although it can exist without the intellectual virtues of science or wisdom or art.

(58a5) All intellectual virtues except prudence can exist without moral virtue, but prudence presupposes moral virtue.

Q. 59 Relation of Moral Virtue to Passion

(59a1) Moral virtue is not a passion because it's not a movement of the sense appetite, which includes the irascible and concupiscible powers (see 56a4R).

(59a2) Contrary to the Stoics, passions can coexist with moral virtue, when they are "reduced to a mean."

(59a3) Contrary to the Stoics, virtue can coexist with sorrow. (Thomas is thinking of lupe or "pain" in Aristotle NE 7.13.1153b2, distress in the Stoics.)

(59a4) Not all moral virtues concern the passions. Justice, for instance, is about the will; justice concerns operations (which are active).

(59a5) Contrary to the Stoics, neither fortitude nor temperance occur without the passions, although justice can be without the passions. (Joy, which results from an act of justice, is in this case not a passion at all.)

Q. 60 The Distinction of Moral Virtues from Each Other

(60a1) There are distinct moral virtues, i.e., not just one, given that they are habits of the appetitive part of the soul, which differ specifically according to differences in their objects. The object of the appetitive power is a desirable good which differs according to the diverse relationship it has to reason. (r1)

(60a2) Justice is about operations, whereas temperance, fortitude, and mildness are about passions.

(60a3) All the moral virtues that are about operations agree in the general notion of justice, which is about what is due to another. Religion is the virtue by which we render what is due to God, piety . . . to our parents or to our country, gratitude . . . to our benefactors.

(60a4) There are different moral virtues about different passions. Fortitude is about fear and daring, temperance about concupiscible desire, mildness about anger.

(60a5) Moral virtues must be differentiated according to their ordering to reason. "The human good may be the object of love, desire, and pleasure; it may be taken as referred to bodily sense or to some interior apprehension of the soul, referred either to the good of man himself or to his good in relation to others. Every such diversity differentiates virtue."

Virtues toward others: friendliness, truthfulness, well-bred insolence.
Virtue relative to good discernible by sense of touch and related to the body: temperance
Virtues in concupiscible power: temperance, liberality, love of honor
Virtues in irascible power: fortitude, mildness, magnificence, magnanimity
Virtue dealing with external operations: justice

Q. 61 The Cardinal Virtues

(61a1) Some of the moral virtues are appropriately said to be principal or cardinal virtues. The intellectual virtues apart from prudence do not rank as cardinal virtues because, although they relate to a superior faculty, i.e., intellect, they are not prior with respect to the good (and virtue as such refers to the good).

(61a2) There are four cardinal virtues.

Prudence is in the rational power, which is rational essentially. Justice is in the will, i.e., reason put into operations, which is rational by participation. The will is an active power. Fortitude is in the irascible power, which is rational by participation. The irascible power is a passive principle. Temperance is in the concupiscible power, which is rational by participation. This power too is a passive principle.

VirtueSubject of the virtue
--a power of the soul
How is it rational?      Is the power active
or passive?
PrudenceRational powerEssentially
JusticeRational appetite, i.e., will,
reason put into operation      
By participationActive
FortitudeIrascible powerBy participationPassive
Temperance      Concupiscible power   By participationPassive