Proverbs 8:12

I, wisdom, dwell in prudence, and I find knowledge and discretion.

Aristotle (Rhetoric, To Alexander 11)

It is characteristic of sensible men to profit by the examples of their predecessors and so try to avoid the errors of evil counsel.

Aristotle (Rhetoric, I, 9)

Prudence [phronēsis: practical wisdom] is that excellence of the understanding which enables men to come to wise decisions about the relation to happiness of the goods and evils that have been previously mentioned.

Matthew 7:24-27

“Everyone then who hears these words of mine and does them will be like a wise man who built his house upon the rock; and the rain fell, and the floods came, and the winds blew and beat upon that house, but it did not fall, because it had been founded on the rock. And everyone who hears these words of mine and does not do them will be like a foolish man who built his house upon the sand; and the rain fell, and the floods came, and the winds blew and beat against that house, and it fell; and great was the fall of it."

St. Augustine (cited in Aquinas)

[P]rudence is love discerning aright that which helps from that which hinders us in tending to God.

St. Bernard of Clairvaux (On Consideration, “The Four Primary Virtues”)

Prudence is the mother of Fortitude, nor ought any deed of daring to be called fortitude, but rather rashness, if it be not the child of prudence.

St. Isidore of Seville (Etym. x)

A prudent man is one who sees as it were from afar, for his sight is keen, and he foresees the event of uncertainties.

St. Thomas (ST II-II q47, a11, ans,).

Political prudence … is directed to the common good of the state.

Catechism of the Catholic Church 1806

Prudence is the virtue that disposes practical reason to discern our true good in every circumstance and to choose the right means of achieving it; "the prudent man looks where he is going." (Prov. 14:15) "Keep sane and sober for your prayers." (1 Pet 4:7). Prudence is "right reason in action," writes St. Thomas Aquinas, following Aristotle. (STh II-II, 47, 2) It is not to be confused with timidity or fear, nor with duplicity or dissimulation. It is called auriga virtutum (the charioteer of the virtues); it guides the other virtues by setting rule and measure. It is prudence that immediately guides the judgment of conscience. The prudent man determines and directs his conduct in accordance with this judgment. With the help of this virtue we apply moral principles to particular cases without error and overcome doubts about the good to achieve and the evil to avoid.

The Integral Parts of Prudence, Summa Theologiae II-II, question 48, article 1

The integral parts of Prudence are those parts of the virtue which are necessary for the virtue to be exercised perfectly. Analogous to the foundation, walls and roof of a house, without them the house (one’s action) will be shaky, if not dilapidated.

They, therefore, concern the things the prudent person must know, in order to judge rightly, as well as the things to be concerned with in judging and putting the decision into action.

The exercise of the virtue is not perfect without all of Prudence’s integral parts. An imperfect act of virtue, therefore, is imprudent, even if the moral object (the thing done) and the intention of the will is good.

Prudence as a Cognitive Virtue (Knowledge):
  1. Memory (Past Experience) Almost every moral decision shares some commonality with previous decisions and previous circumstances. The memory of our past moral choices helps guide our present ones.
  2. Understanding (Present Experience) Rather than a mere factual knowledge of the present circumstances, Understanding is a comprehension of their relationships to important principles. It is said to be “a right estimate of some particular end” (ST II-II, q49, a2, ad1).
  3. Docility (Teachability) One person’s knowledge is finite and their experience is limited. A willingness to learn from the knowledge and experience of others is essential to a prudent decision.
  4. Shrewdness (Quick Conjecture) While docility enables a person to learn from the experience of others, shrewdness is the ability to quickly make “an easy and rapid conjecture” oneself (ST II-II, q.49, a4 ans.). This is especially important when a decision must be made quickly, without the opportunity for investigation or taking counsel.
  5. Reasoning (From Knowledge to Judgment) To reason is to proceed from what is known to a conclusion (ST II, q49, a5). It is the proper work of the human intellect, which unlike the angels and God does not simply intuit what is true. Reasoning is, therefore, central to a prudent moral decision.
Prudence as Commanding and Applying Knowledge (Judgment):
  1. Foresight (What Befits the End) In order to effect the completion of a chosen action, it is necessary to take into account contingent possibilities, in so far as one can foresee them––leaving that which can’t be foreseen to God’s Providence.
  2. Circumspection (Attention to Circumstances) For an action begun to continue to be a morally good means to the end, attention must be made to the circumstances along the way. While foresight tries to anticipate them, circumspection reasons about those which actually occur, adjusting as necessary to achieve the end by moral means.
  3. Caution (Avoiding Obstacles) Caution is directed to being aware of obstacles to the end, and the greatest obstacle is evil––whether evil mixed in with the good, or evil masquerading as a good. Caution regarding evil is, therefore, necessary for an action to be prudent.


Sinful Imprudence (St. Thomas, ST II-II q53)

As with all sins, an action can be imprudent without moral fault. Factors beyond the knowledge of the person may be the cause, whether ignorance of the truth, a lack of opportunity to acquire it, or due to the deception of another.

On the other hand, the failure to exercise prudence is sinful if it is due to a lack of diligence:
• either in being formed in the knowledge necessary for the moral act (see Conscience), or,
• in those things related to the judgment about what to do or avoid, or in carrying it out (the parts of prudence).

Different species or kinds of imprudence

St. Thomas identifies various ways of sinning against prudence, in relation to its different parts (ST II-II q53):

Precipitation Acting without consideration. This effectively neglects all or most of the elements morally necessary for a prudent action.

Temerity (fearing to act) – lack of docility, memory, or reason

Thoughtlessness – by lack of caution and circumspection

Inconstancy – by improvidence, lack of understanding (intelligence) and of shrewdness. Finally, he identifies the vice of Lust as the progenitor of these defects, which may explain a lot about the lack of prudence in society today.

Aristotle (Ethics, vi-vii)

"pleasure above all corrupts the estimate of prudence," and “the man who is incontinent through anger listens to reason, yet not perfectly, whereas he who is incontinent through lust does not listen to it at all."

Thus, following Aristotle and St. Gregory the Great, Aquinas identifies the vice of Lust as the progenitor of these defects.

This explains a great deal about the lack of prudence in the Church, as well as in society, and politics especially, which often seems primarily ordered to protecting and advancing lust and its fruits as rights and freedoms.