How can one gradually eliminate the concept of "self" until achieving "no-self"?
I once heard a story: A house was rumored to be haunted. The owner invited many spiritual masters to perform rituals, but none could resolve the problem, so he eventually moved out and sold the house.
The next owner was a fearless man. Though he had heard that the house was haunted, he didn't take it seriously. However, after moving in, one night he was startled awake by faint crying sounds. Alarmed, he sprang out of bed, listened carefully, and found that the crying continued. He turned on all the lights and searched every corner of the house but found nothing. Left with no other choice, he retreated to his room and stayed awake the whole night.
In the following days, the man was frequently awakened by the crying sounds, tormented to the point that he could not sleep. He thoroughly searched every part of the house but found nothing. One day, when the crying started again, he couldn't take it any longer and carefully traced the source of the sound. He finally located it in the kitchen—beneath the sink. He grabbed some tools, dismantled the sink, and dug into the ground, exposing the drainage system.
The sound stopped. Before him lay two giant salamanders.
As it turned out, the so-called haunting was caused by these creatures. Later, he discovered that the previous owner had once bought several giant salamanders and placed them in the sink. Two of them had accidentally slipped into the drainpipe. Over time, the owner forgot about them, not realizing they had remained in the sewage system, growing larger and occasionally making noises.
Whether the story is true or not is uncertain. But if you wish to attain "no-self," you must do as the man did in the story: Investigate thoroughly, search every part of your mind and body, ensuring that no "self" is present. Then identify the reason why you believe in the existence of "self." Finally, eliminate that cause, and you will achieve "no-self."
To determine whether a house is haunted, you must first understand its structure—its rooms, attic, basement, and other spaces—so that you leave no area unchecked during your search. Similarly, to determine whether "self" exists, you must first understand the structure of your own body.
According to research, our body is composed of bones, muscles, liver, heart, kidneys, hair, skin, eyeballs, and other solids, as well as liquids like blood, bile, saliva, and sweat. These solids and liquids are further composed of proteins, water, fats, and other substances.
If you analyze these components separately, you'll realize that proteins, water, and fats are not "self." If any of these were "self," then when they undergo metabolism and change, wouldn't "self" also disappear? The organs, tissues, blood, nerves, and everything they form are clearly not "self" either. If they were "self," then organ transplants would mean transferring "self" to someone else.
When our body interacts with the external world, five types of sensory perceptions arise: colors (vision), sounds (hearing), smells (olfaction), tastes (gustation), and textures (touch). Each of these perceptions leads to corresponding emotions, imagination, and thoughts. Beyond this, humans recall past experiences (memory), which also trigger emotions, imagination, and thoughts.
If you examine these perceptions separately, you'll find that colors are not "self." If colors were "self," then when one is blind, "self" would cease to exist. The same applies to sounds, smells, tastes, and tactile sensations. Emotions, too, are not "self." If happiness were "self," then when happiness fades, "self" would fade away. Sadness and thoughts follow the same logic—they constantly change, fluctuating in an unpredictable manner. If they were "self," then "self" would die and resurrect repeatedly, which contradicts our common understanding of identity.
After thoroughly examining all phenomena, you will conclude: None of these are "self."
However, this only proves that the phenomena you are aware of are not "self." It does not necessarily mean that "self" does not exist at all. "Self" might be like a ghost hiding in unknown areas—secretly looking, listening, smelling, tasting, and touching; recalling, thinking, imagining, and making decisions; controlling the body to move forward or backward.
To investigate further, you need some knowledge of biology and cognitive neuroscience—such as the relationship between cells and DNA, muscle contraction mechanisms, bioelectric transmission, and the principles of sensory perception. By comparing these scientific concepts with your personal observations, you can gain deeper insight.
Biologically, walking is a process where muscle contractions move the skeleton. Muscle contractions themselves involve complex chemical reactions. While you may have the intention to walk, you don't actively command each individual muscle to extend or contract. You don't manually manipulate calcium ions or interact with troponin to trigger muscle movement—these processes occur automatically.
If you observe your own walking process carefully, you'll realize that movement isn't simply a straightforward "left-right-left" pattern. Instead, it involves intricate movements of the torso, waist, thighs, calves, feet, and joints—all happening without deliberate control. If you try to consciously control each part, you'll find that you can't walk properly.
This demonstrates that walking is not directly controlled by "self." It's like taking a taxi—you tell the driver, "I want to go to the museum," then you fall asleep. Upon waking up, you've arrived. You then refuse to pay the driver, arguing, "Since I wanted to go there and said the words, it means I made everything happen. In fact, the driver should pay me because I took him and his car along with me!"
Similarly, vision arises when light interacts with visual cells, generating bioelectric signals that are transmitted to the visual cortex. This means vision is a product of supporting conditions rather than something actively "looking outward."
Now consider: If there truly were an inner "self" looking outward, then removing the eyes should improve vision, just like removing a window enhances one's view of the outside scenery. Yet, when the eyes are removed, vision ceases—clearly showing that nothing within the body is actively looking. The same logic applies to hearing, smell, taste, touch, memory, and other mental phenomena.
Thus, we conclude: Sensory perceptions and bodily actions arise due to conditions rather than being directed by an independent "self."
We now know that these phenomena are not "self," nor are they controlled by "self." But you may still feel that "self" must exist—after all, humans are not entirely passive, blown by the wind like leaves. At the beginning of every action, there must be a commander initiating everything, like an emperor leading his army. Right?
Before answering that, let's conduct an experiment. Right now, you might suddenly hear the chirping of birds or the sound of passing cars. Before this moment, you had no prior knowledge that these birds or cars existed, nor did you anticipate hearing them. The sound suddenly appeared, and only then did you realize it. Your brain then recalled past experiences to associate the sounds with birds or cars, forming the thought: "I hear bird sounds" or "I hear car noises."
This process illustrates that perception arises first, then mental associations follow, constructing concepts like "I perceive."
If you continue analyzing this line of thought across all experiences, you will realize: Every aspect of our understanding—including our bodily sensations, the external world, and abstract thoughts—is built upon sensory perception and memory. The concept of "self" is simply another idea formed by this continuous cycle of perception and association.
Once this is fully understood, the illusion of "self" dissolves, and suffering ceases. Like the great sage born in the Śākya clan 2,600 years ago, you will realize: "I have attained the path of the ancient sages, followed their footsteps, and now walk their way."