Prudence, Right Judgment, and Living in Reality
Prudence is the perfection of reason, or, the perfection of the natural capacity of the soul to see reality as it is. More than just a view of the physical reality around and about us, prudence sees the spiritual and relational reality around us. Another way to describe prudence is discernment. A prudent person can discern what ideas and acts conform to reality and which do not. But prudence is more than just an ability to see or assess. It is also the ability to act upon these assessments. Thus, a prudent person discerns what is a right act and acts upon it. This is not merely utilitarianism because it does not see reality as isolated bits and pieces, but as a whole and, in the Christian sense, under the rubric of God’s revealed word in scripture. As a result, prudence is discernment and action in conformity to reality as it is revealed in creation and in scripture. But prudence is not charity. Charity is the motivation for all good Christian acts. Prudence is the deliberative, judicial, and decisive means by which Charity manifests itself. Therefore, Charity motivates every portion of the prudential process. Only because we are motivated by love of God can we sense that we must deliberate, decide what to do, and act upon that decision. Yet Charity does not take the place of prudence but undergirds it. We need Prudence to properly make decisions that are loving towards God and Man.
Prudence is also not the same as casuistry. That is, it does not imagine every situation ahead of time and assign a rightness to it in advance, for we cannot conceive of every possibility, and it would take away from our present duty to do so. Instead, prudence relies upon the situation at hand to determine the rightness of an act. How, then, does prudence avoid relativism or, more properly, subjectivism? First of all, though every situation is different, the underlying reality is objective. This means that though there may be an infinite variety of acts that are produced through prudence, these are a small subset of the infinite variety of acts that could otherwise be produced. Reality limits the kinds of decisions that can be made in any situation. The reality described is not just the reality of the physical world around us, but the reality described in scripture. Therefore, the general laws of God limit the variety of responses that can obtain in any given moment. For example, “thou shalt not steal” remains a moral reality to which prudence must conform. Thus Pieper says, “Thomas [Aquinas, with regard to] the performance of man’s proper duties to be just (in which category falls his obedience to the laws of Church and State), remarks that these in particular are most independent of changes in situations and are therefore most likely to be fixed once and for all.” Therefore, situational relativism is a vast domain, but is clearly limited. Learning what those boundaries are is why one must become familiar with scripture, the physical world, and the people in it.
What becomes difficult is when one encounters situations not mentioned in scripture or the teaching of the church. This is where prudence particularly outshines casuistry: casuistry is limited by the number of scenarios one has imagined ahead of time and is mechanical, but prudence is a virtue of the heart. In regards to man’s duties as well as in these more subjective cases, however, we need humility to give attention especially to three things: 1) the word of God, 2) outside expertise, and 3) prayer. We must read the word of God regularly so as to instill in our minds and hearts what the realities our world are of (both physical and spiritual). Where needed, consulting others with an expertise or with experience in a particular area may be necessary; we need the humility to trust the knowledge and abilities of others. Finally, prayer is a prerequisite for Christian prudence. Without prayer there can be no objective vision of reality. God is the only one who has an objective “birds’ eye” view of reality. He not only can grant supernatural wisdom to us, but can influence outcomes.
As with all virtues, however, it must be emphasized that prudence is a goal to pursue and not an achievement to be had. One becomes able to make prudent decisions quickly only through practice. Without expertise or practice, there is a gap in one’s knowledge of the situation and prudent decision-making is rendered impossible. Prudence also is different from the other cardinal virtues in that it is not an end, but a means. One must be prudent to pursue justice, fortitude, and temperance. Without prudence these other three cannot come into existence no matter how many other requisite characteristics are present . In this sense prudence is the mother of all moral virtues.
 (action according to reason = κατὰ λόγον)
 Matthew 6:34 and 10:19.
 G.K. Chesterton’s fictional character Father Brown, in The Blue Cross, has the following conversation with the thief Flambeau:
Flambeau: ‘[W]ho can look at those millions of worlds [in the night sky] and not feel that there may well be wonderful universes above us where reason is utterly unreasonable?’
Brown: ‘No’ said the other priest; ‘reason is always reasonable.’
Flambeau: ‘Yet who knows if in that infinite universe—?
Brown: ‘Only infinite physically,’ said the little priest, turnign sharply in his seat, ‘not infinite in the sense of escaping from the laws of truth.’
 (The Four Cardinal Virtues. Notre Dame Press, 1966:pp.25-26)
 This is where casuistry may be helpful in training the habits, as long as it does not replace a prayerful attitude and a proper appreciation for the situation at hand.
Painting: Wisdom and Prudence by Francesco Rustici, 1610-1625