This morning I saw raccoon tracks on the clearing at the top of the hill in the monastery where I live. They ran across a part of the clearing that I had swept the night before, and it was because I had swept the area that I could actually perceive the raccoon tracks, in both senses of the word perceive: one, to detect that they were there, and two, to be able to identify them.

The Thai ajaans like to use this as an analogy: You sweep the monastery, get everything clean, so that you can detect what’s been coming and going in the monastery. In the same way, you try to sweep your mind clean—developing your mindfulness and concentration to get the mind still—so that you can perceive things arising in the mind. If greed, lust, or any other unskillful emotion arises, you want to be able to perceive it early on so that you can deal with it appropriately and in time.

The two senses of the word perceive in English—to detect something and to identify it—are actually two separate words in Pali. The first, simply acknowledging the presence of something, would be an act of viññāṇa, consciousness. You cognize it.

The perceiving, saññā, is the act of identifying. Of course, my ability to identify the raccoon tracks depended on more than just the fact that I had swept the clearing. I had to remember the characteristics of raccoon tracks from my previous experience. Memory is an important part of this type of perception.

Some people limit the word saññā simply to memory, but there’s more going on in the process than just that. To identify something right in front of you in the present moment, you remember that certain characteristics mean this or that, but you also have to apply that knowledge right here, right now to recognize what’s going on.

We see this often in the Vinaya, the rules that the monks have to follow. The severity of the punishment for breaking a rule, in many cases, is measured by how you perceive the object you’re involved with at the moment you’re involved with it. For instance, if, with lustful intent, a monk touches a woman while perceiving her to be a woman, the offense is serious. If he were to perceive her as something else—such as a man or a mannequin—the offense would be much less serious. This is not a matter of mere memory: You’re not just remembering whether what you touched was a man or a woman. What matters is how you identify what you’re touching while you’re touching it.

As you live by the rules and get to think of your actions in their terms, you see that they place a lot of emphasis on this role of perception: how you identify what you’re dealing with, and how important it is to get your perceptions right.

Take, for instance, the case of touching a woman you perceive to be a man. Even though the punishment imposed by the Vinaya isn’t serious, the consequences in real life can be much more drastic if the woman takes offense at being touched. So you have to check your perceptions carefully to prevent trouble of that sort.

Or take the case of the monk who, seeing a pile of clothes on a chair, perceived it just as a pile of clothes and sat down very forcefully on top of it. Actually, there was a baby child wrapped up in the pile of clothes, and the child died because of the monk’s carelessness. In this case, the Buddha said, before you sit down always make sure that you correctly perceive what you’re sitting down on.

In other words, check your perceptions of the present moment to make sure they’re right. This isn’t simply a matter of remembering names. You have to correctly identify what you see and hear, and at the same time think about its meaning or value.

This connection between identity and value is a natural one. As beings, we’re defined by our need to feed. Even as very small children, we identify with our physical and emotional hungers, giving them value, and then identify the things in the world around us by how well they’re able to satisfy those hungers. So when we use perceptions, it’s not a disinterested activity. It’s driven by our desires and by the values our desires give to things.

This connection between identity and value is reflected in the Thai definition of the word saññā: cam dai, maai ruu. Cam dai means to recognize or remember something. Maai ruu means to label it and to determine what it means.

In the case of the footprints in the clearing, the fact that they were raccoon tracks meant nothing much, just that we have to be careful: Raccoons can steal things but they pose no real danger. However, if the tracks had been grizzly bear or wolverine tracks, that would have been another matter. We’d have to be a lot more wary because we now have signs that there are more dangerous animals around.

It’s in this element of the meaning of the perception, or how you perceive the value of what you perceive, that perception plays such a huge role in the practice. If you perceive a certain desire as something worth developing, you’ll deal with it in one way. If you perceive it as a cause of suffering, you’ll deal with it in another way. And the difference in how you deal with it will make a difference in whether you experience suffering or well-being as a result. When we adopt the practice, we’re adopting a particular way of ordering our perceptions, judging them by their efficacy in helping us to find total freedom from suffering.

Another teaching from the ajaans is that when you focus on the five aggregates—form, feeling, perception, fabrication, and consciousness—you can start out with any one of the five, and it’ll give you insight into all the rest. For instance, you can focus on the body, analyze your attachment to the body, and the analysis will start spreading around to feelings and perceptions and fabrications and consciousness as well. What’s particularly important is how it spreads to include your perceptions.

Think, for instance, of how the contemplation of the body progresses. It’s all a matter of learning how to perceive the body as not worthy of attachment. We ordinarily come to the practice with the perception that the body is worthy of attachment. We correctly perceive it as a body, but we have a wrong perception about its meaning and value.

So we contemplate the parts of the body to see that they’re not anything worth identifying with. We contemplate the drawbacks of the body in terms of its many potential illnesses. We learn to develop the perception of its being inconstant, stressful, not-self, and unattractive, all in order to change our ideas about its value. After all, it’s through the value that we get attached to it. If we learn to perceive it as having not much value at all—at least not much value in terms of how our lust or pride might want to value it—then the attachment goes away.

Now, the body does have value as something we can use in the practice, so we take care of it just enough to keep it going, so that we can continue our practice in reasonably good health. That’s a correct evaluation for the body. But to arrive at that evaluation requires that you strip away a lot of your other wrong perceptions.

The same principle applies to feelings. As you sit in meditation, you’re bound to encounter feelings of pain. As long as you perceive the pain as being the same thing as the part of the body in which it’s located, it’s going to be very difficult to not suffer from it. Your perception that it has invaded the body you claim as yours is what creates the bridge between the physical pain and your mental pain.

So one of the instructions in dealing with physical pain is to ask yourself, “Is the physical pain the same thing as the body?” The body of course, is the four elements. Pain is something else, but we’ve glommed the two together. So how do you un-glom them? One way is to ask yourself, “Where is the sharpest point of the pain right now?” Instead of running away from the pain, go toward it, be proactive, and you’ll see that the sharpest point moves around. You keep following it around and around until there’s a weird sense that “Yes, the pain does separate out from the body”—so much so that it’s as if they’re no longer in the same place anymore. When you separate them out, sometimes the pain remains, and other times it disappears. What’s really weird is when it slips along your nerves into your heart and disappears there, which shows how much of a role the perception plays in your experience of the pain.

So no matter which of the aggregates you focus on, the analysis always seems to come down to perception, and especially the perception of value, the perception of meaning.

This relates to Ven. Sāriputta’s answer to the question: “When you go to a foreign land and intelligent people ask you, ‘What does the Buddha teach?’ how do you answer them?” His first answer was, “The Buddha teaches the end of desire and passion.” If the people asking the question are intelligent, they’ll then ask, “Desire and passion for what?” His answer: “The five aggregates.” “Why is that?” “Because if you have passion for these things, then when they change, you’re going to suffer. But if you don’t have passion for them, then no matter how much they change, you’re not going to suffer.”

He’s boiling the Buddha’s teachings down to a value judgment: The aggregates are unworthy of passion. This, of course, is an issue of perception. If you see these activities—and they are activities, rather than things—as worthy of pursuing, you’re not going to let them go. You’re going to keep doing them again and again. But when you begin to see that they can’t provide the happiness you want, and particularly when you learn about the happiness that can come when you do let go—that’s the message of the third noble truth—then you see they’re not worth pursuing. You stop doing them, and you don’t have to suffer from them anymore.

So the practice is a matter of training your perceptions to be able to identify not only what an aggregate is, but also what it’s worth.

This is where the perceptions of inconstancy, stress, and not-self come in: to call into question the worth of these things, the meaning you give to them. If something that you’re attached to is undependable and causing you pain, is it worth identifying with? No. Apply these perceptions first to activities that are clearly unskillful and then you’ll be in a position to apply them even to skillful ones.

When you can use these perceptions to let go of all the aggregates—including even the perceptions that tell you to let go—then you open to something that’s even greater than you can imagine, in which there’s no perception, but there is the greatest happiness possible, a happiness that doesn’t have to depend on perceptions of its worth.

So perception plays a huge role in the practice, both in identifying what’s what and in learning to retrain your perceptions of the value and meaning of what’s what. If you focus on this issue of perception, you find that you can go far in freeing the mind from its attachments—which are based on mistaken perceptions—and developing perceptions that allow you to let go.

Of course, you eventually have to let go of even these perceptions because they, too, are aggregates. But that’s simply a part of the Buddha’s strategic approach in general: You use aggregates to get beyond the aggregates. Then you let them all go.

When I was teaching a retreat in Canada last year, one of the retreatants mentioned that she had been told that we can’t change our perceptions, which is probably one of the most un-Buddhist teachings imaginable. It’s because we can change our perceptions—learning how to identify the world in a new way, learning how to identify its value in a new way—that the whole idea of learning and practicing the teachings makes sense. It’s because we can change our perceptions that we can decide to follow the path. It’s because we can change our perceptions that we can be free.