The Three Dharma Seals are three concentrations: on impermanence, nonself, and nirvana. They are the mark of every Buddhist teaching and are the keys to touching every phenomenon deeply and opening the door of reality. Mindfulness and concentration are the energies we can use to be in touch with something. When we are in touch with our heart, for example, our heart feels this and is very happy to receive our attention. If we use our mindfulness to touch it deeply enough, we see its impermanent nature. Even if our heart was healthy three months ago, that doesn’t guarantee it will be in good health forever, especially if we don’t look after it and take care of it. At the same time, we see the nonself, interdependent nature of our heart. The well-being of our heart depends on many other elements, like the health of our other organs, the things we eat and drink, our environment, and hereditary factors.
When we look deeply into the impermanent and nonself nature of our heart, we begin to understand the difficulties it has. We feel love and wish to care for it, and our way of acting can transform the state of our heart. The same applies to every other part of our body. We stop smoking, eating, and drinking in ways that cause our liver to be exhausted, our lungs to malfunction, or the flow of blood to and from our heart to be constricted. When we use the Three Dharma Seals as a key to open the door to the reality of our body, we come to understand it deeply. Only once we understand it deeply will we look after it carefully.
In the same way, we can use these three keys to open the door to the reality of all phenomena. Impermanence and nonself belong to the world of phenomena, the historical dimension. When we touch phenomena deeply, looking at the world in terms of impermanence and nonself, then we are in the sphere of nirvana, the ultimate dimension, and we feel at ease and without fear. Impermanence and nonself are in essence the same; they both mean the absence of a separate, permanent self. It is called impermanence when looked at in terms of time, and nonself when looked at in terms of space. Our store consciousness, our unconscious mind, is impermanent and without a separate self, and—just like a flower or a piece of bread—it contains within itself all phenomena in the cosmos.