The next step in the dance of prudence is understanding, for Saint Thomas. Understanding gives us the ability to see how this principle applies to this case. Each event is different from the one before. Understanding helps us to see the differences – especially those that are not immediately obvious. This usually requires us to think something through, and not simply react on the basis of how something appears on the surface.
Let’s go back to Jack, our small-business owner about whom we were thinking yesterday. Let’s say he has a bookshop. Let’s say his down-and-out employees help themselves to the cash. Now Jack had better think this through. He wants to help the needy – this is an important principle. So he turns a blind eye to the disappearing cash. But sooner or later, this is going to have an adverse effect on his business. Sooner or later other principles, that are arguably more important, get buried – such as his obligation to support his family. If the business suffers, he will soon be in a position to help no one, including himself.
Good people are not usually attracted to doing bad things, but to doing a good thing in an immoderate way, at the wrong time, under the wrong conditions. With understanding we acquire the ability to set priorities, to determine which good thing I need to be doing now, to say no sometimes to one good thing in order to safe-guard a greater good, and to see what is really at stake in a given situation.