Virtue is a Greek term meaning “character excellence” or “excellence in being.” When translated into Latin, the word is “virtus,” meaning “effectiveness in action.” Virtue is how we can cultivate good character because it provides us with a moral compass and is the key to unlocking human flourishing and fulfillment.
Prudence is the first of the cardinal virtues (the others are justice, fortitude, and temperance). It guides the other virtues and guides the judgment of conscience.
Prudence enables us to choose good means to a good end. It guides our practical decision-making in individual, concrete circumstances and provides for effective execution once a decision is reached. With the help of prudence, we learn from our experiences and correctly apply moral principles to real-life situations (Catechism, no. 1806).
Some notes I found about prudence that I like:
St. Augustine says: "Prudence is the knowledge of what to seek and what to avoid."
"The virtue of prudence is the mold and “mother” of all the other cardinal virtues, justice, fortitude, and temperance. In other words, none but the prudent man can be just, brave, and temperate, and the good man is good in so far as he is prudent." — Pieper, Josef. Four Cardinal Virtues, The (p. 10). University of Notre Dame Press. Kindle Edition.
The three stages of prudence for acting properly are deliberation, judgment, and decision.
Errors in judgment can creep in through defects of prudence or through “false prudence.” Defects include thoughtlessness, rashness, negligence, indecisiveness, and inconstancy in execution.
True prudence isn’t only concerned with a good end but also good means to that end.
Prudence is something we develop with practice; it builds on what we have learned through earlier experience. Aristotle taught that "...virtue is both originated and fostered by teaching; it, therefore, demands experience and time." Although it may be difficult at first, Prudence becomes easier as we incorporate what we have learned into the mental processes by which we make our choices. Any act—good or bad—becomes habitual, or "second nature," through repeated practice. The value of the good habits we call virtues is that they make self-mastery and the joy of leading a morally good life easier.