Joseph Goldstein & Jack Kornfield

On the most fundamental level our lives are composed of six experiences: sights, sounds, tastes, smells, physical sensations, and mental events. From this perspective our entire complex world is just changing sights, sounds, tastes, odors, feelings, and thoughts.
In the practice of meditation we make an effort to be aware of our immediate experience of life, of the changes in these six sense doors, including the mind as a sixth sense.
Over time as we do this we come to realize more and more clearly what are called in Buddhism the Three Basic Characteristics of all conditioned phenomena [1.e., phenomena depending for their existence on supporting conditions or constituents]: Suffering, impermanence, and non-self.
As our meditation progresses it will give us a deepening personal and intimate sense of these three characteristics, the realization of which can bring an end to desire, craving, grasping, and clinging- the main causes of our suffering.
Suffering - Let us begin by considering suffering (Pali, dukkha), which is where the Buddha began his teaching. Suffering includes that which is unsatisfactory and unreliable. To consider the suffering experienced by millions born on this earth - the poverty, hunger, violence, and sickness - is a sobering thought. And it is important for us to acknowledge worldwide suffering on our spiritual path.
Yet to understand suffering deeply, we must look inwardly as well. Let us consider our direct and immediate experience of suffering, when we experience life as uncertain, unstable, and oppressive or we feel anxious, depressed, or feel that real happiness is somehow eluding us.
As we grow up each stage of childhood, adolescence, trying to become adults, aging, and sickness has its share of suffering. And if you watch carefully during the course of an ordinary day you can see that within yourself dissatisfaction, discontent, fear, loneliness, judgment, irritation, physical pain, disappointment, and insecurity are inherent in much of our experience.
Even the objects that contact the various sense doors can be a source of suffering such as harsh sounds on the ear, pressures on the body, or intense light on the eyes.
Impermanence - Impermanence (Pali, anicca) is the second of the Three Characteristics. And just as we have avoided the truth of suffering so we try to avoid impermanence. Look at it right in this moment: A sound comes then it is gone, a thought arises and passes away. Sight, taste smell, touch, thought all arise as they contact their respective sense objects, depending on these object, all impermanent and fleeting. In Buddhism we acknowledge and recognize that everything in the universe, in this very moment, is in the process of changing into something else.
Most people try to create an illusion of stability, solidity, and security with regard to their body, the sort of person they are, the way they live, and things they do. We find it difficult to accept the truth of impermanence. We try to overcome the fact of how quickly pleasure passes. We try to string together enough pleasant sense experience as to seem to make them stay. We cannot stop the body or the mind from constant change. And when we want these truths to be other than what they are, it is bound to lead to frustration.
Non-Self - The Third Characteristic is non-self (Pali, anatta) and it is the hardest fro the Western mind to comprehend. This means that there is no entity separate from the flow of experience, no "self" to whom it is happening.
Our primary delusion is the belief that there is an "I," a self, an ego that is solid and separate from all else. But this sense of "I" is made up only of an identification process. "This is me. This is what I do. I like this. I'm going there. I want to be this way," and so on. This sense of self is created entirely by thought and has no substance. There are only thought bubbles. If your meditation has progressed to the point where you are experiencing a still and quiet mind, you will then begin to feel the ego and sense of self fading to a level where you may now feel each moment directly as the empty, impossible to possess nature of reality.
If you are not caught up in all your thoughts about all your experiences then there is simply experience in each moment: Just seeing, hearing, smelling, tasting, touching, and cognizing all without a stable and permanent self.
Sometimes when one sits in meditation the mind is as if someone left a radio on and one cannot shut if off or control the programming. Thoughts, memories, and emotions- as if programming themselves- arise and pass away. Likewise, bodily sensations arise, change, and pass away of their own accord. Can we tell the mind not to think or the body not to grow old?
While the depth of the truth of non-self is profound if you practice meditation, the meaning will reveal itself and it will become crystal clear to you in a way that no book or person could have possibly explained…