Concentration is not something exclusive to Buddhism. Even in mundane activities, people use concentration. No matter what work you do, if you’re not intent on it, you won’t succeed. Even our ordinary everyday expressions teach concentration: “Set your heart on a goal.” “Set your mind on your work.” “Set yourself up in business.” Whoever follows this sort of advice is bound to succeed.
But apart from mundane activities, whoever comes to put the Buddha’s teachings into practice is sure to perceive the great worth of concentration. To be brief: It forms the basis for discernment, which is the central principle in the craft taught by the Buddha, the craft of the heart.
“Discernment” here refers to the wisdom and insight that come only from training the heart. People who haven’t practiced concentration—even if they’re ingenious—can’t really be classed as discerning. Their ingenuity is nothing more than restless distraction—an example being the person who thinks to the point where his nerves break down, which goes to show that his thoughts have no place to rest. They run loose, with no concentration.
People with responsibilities on the level of the world or of the Dhamma should train their hearts and minds to be concentrated. Then when the time comes to think, they can put their thinking to work. When the time is past, they can put their thinking away in concentration.
In other words, they have a sense of time and place, of when and where to think. People without concentration, who haven’t developed this sense, can wear out their minds; and when their minds are worn out, everything breaks down. Even though they may have the energy to speak and act, yet if their minds are exhausted, they can’t accomplish their purpose.
Most of us use our minds without caring for them. Morning, noon, and night; sitting, standing, walking, and lying down, we don’t rest for a moment. We’re like a man who drives a car or a boat: If he doesn’t let it rest, he’s headed for trouble. The boat may rust out or sink, putting all that iron to waste, and when this happens, he’s in for a difficult time. When a person’s mind hasn’t been developed in concentration, it can create difficulties for its owner’s body, as well as for the bodies of others.
Thus people who train their minds to attain concentration are of use to themselves and to others; people who don’t train their minds to attain concentration will cause harm to themselves and to others. To attain concentration is like having a strategic fortress with a good vantage point: If enemies come from within or without, you’ll be able to see them in time.
The discernment that comes from concentration will be the weapon enabling you to wage war and destroy defilement. Whatever is worthwhile, you will keep in your heart. Whatever is harmful, you will throw out. The discernment that comes from concentration will enable you to tell which is which.
This reflection by Ajaan Lee Dhammadharo is from the Thai Forest Ajaans book, The Craft of the Heart, “Concentration: Questions & Answers,” translated into English by Ṭhānissaro Bhikkhu.