There are several words for prudent that are used throughout the book of Proverbs. This one is slightly different than the others, and as such, is well worthy of our attention for the day. The Hebrew word used here is "arum" which means being crafty, shrewd, or sensible. This adjective can have either a positive or a negative connotation to it. Here in this proverb it is taken in a positive way.
We learn more about this word in the other places it is used positively. In Proverbs 12:16 the prudent man does not take offense at an insult. Thus we see that the sensibility and shrewdness shown is seen in a man not allowing an insult to be the stimulus for a reaction. How often has a reaction to an insult gotten us into trouble? We are insulted by something someone says - and we react. The insult itself is not our problem - but too often our reaction to it exacerbates the problem greatly. The insult, if left alone, would not have caused us more than a few moments of uncomfortableness. But when we react, saying something back, suddenly the problem is ours. If things escalate further there could be a very real problem develop that could take months if not years to solve.
The prudent man also does not flaunt his knowledge before others (Proverbs 12:23). The wise man understands that a "know-it-all" is often ignored - and even at times resented. He reserves sharing his knowledge for situations when he either is asked, or for times when wisdom is badly needed in a situation. The prudent man also takes careful thought of his ways (Proverbs 14:8). He realizes that his actions have consequences, therefore is careful about what he does and says. He takes care how he lives for he knows that wisdom will help him have a much more profitable and pleasant life. Twice in Proverbs (22:3; 27:12) the wise man avoids danger. He knows that stepping into dangerous situations when he does not have to will raise the risk of injury and damage not just to his physical well-being, but also his spiritual and mental well-being as well.
The fool is said to display folly. He does not think before he acts - does not consider his words or his lifestyle. He is quick to do whatever enters his thoughts - and acts without seriously thinking about consequences. Therefore his life is more of a display than a thought out series of actions. What he displays therefore is his lack of thinking - his lack of foresight - his lack of wisdom. He displays foolishness, stupidity, and a lack of a heart for God.
There is a saying that goes like this, "Look before you leap." What that saying communicates is that we should not just look at what is before us as we consider leaping - but it communicates thinking about what you are about to do. This is what the prudent man does and yet, he does far more. He actually thinks and reasons according to what God says in His Word. After taking the time to think - to consider - to be sensible in what he is about to do - he then considers as well whether this action is according to the Word of God. This is what allows him to act with knowledge - even displaying knowledge in the choices he makes - rather than just showing everyone that he is a fool.