The Buddha taught there are five aggregates that make up a being.
- Physical form (the body).
- feelings (sense impressions and the mental tone of pleasant or unpleasant that accompanies them),
- perceptions (our memory).
- mental formations (thoughts, ideas, personality, emotions, moods).
- and consciousness (which arises because of and is shaped by the other four aggregates.)
These five aggregates are interwoven and affect one another, and they are what we identify with as the self. But when we slow down and compose our minds through meditative practises, enough to be able to look at the five aggregates closely, we can see that they are always changing and arise and cease due to causes and conditions.
We cling to them because we identify with them, and this attachment to the impersonal changing phenomena in ourselves and in others causes us suffering. It also leads to rebirth, and further becoming.
Why is rebirth a problem? Because of ageing, sickness, death and loss. Even the glorious devas age and die. Even if one gets a good rebirth and lives a long life in the heavenly realms, that life will one day come to an end, when the karma that brought it into being ceases. Then a being can fall from the heavens and return to the Earth, or worse can fall into the Hell realms where the suffering is intense and long lasting. And all of us if we do not uproot greed, hate, and delusion from the mind can go through this cyclic process over and over, this is Samsara. And because of change and impermanence, for the majority of the time the experience is not pleasant, our time in Samsara is mostly an experience of pain, loss, grief, sorrow and suffering. The happiness is brief compared to the unhappiness.
The thought of reincarnation and rebirth can be challenging for us modern humans with our scientific minds; but it is part of right view in the noble eightfold path. Right view isn't just looking at the life one is living now, it is also looking at the possibility of future lives, of rebirth and how that depends on the karma we generate now, i.e. the tendencies of the mind we grasp and cultivate in this life, which grow in momentum and eventually transform into another being.
Things change, we change, even space which we think of as empty is full of quantom particles in a state of flux, the void is not empty, and even then we are never in the same patch of space twice, because the Earth is spinning, and going round and round the sun, which is itself going round and round the centre of the galaxy, we never experience the same patch of space twice, each moment the space we are in is different, even space itself is change.
The mind always wants to cling to something. Perhaps because of the transient nature of things and the uncertainty this brings. But the clinging causes us suffering, it is not pleasant, because the things we cling and become attached to change, and we can't stop them changing, nothing remains the same, nothing lasts, everything is in a state of entropy and impermanent.
There may be momentary sensory gratification in this life from sense pleasures, but they don't last, and sooner or later one experiences the opposite, because one cannot experience pleasure and gain, without also experiencing pain and loss. The eight worldly winds (pain and pleasure, gain and loss, success and failure, praise and blame) blow in both directions and can change suddenly. One cannot experience one without also experiencing the other. That which arises also ceases. Which can be a comforting truth when one is in pain, but an uncomfortable truth when one is experiencing pleasure. We want the pleasant experiences to last, but alas they don't. They change, and it can be cruel, because even if you manage to get what you want, and can maintain that sensory pleasure, the mind gets bored after a time, the senses become jaded and one starts to crave for something different, everything changes.
The concept of not-self is a tricky one to grasp. Of course there is a self you may say, I mean who is sitting here and typing these words, who is it that practises the noble eightfold path, if not the self? In fact when the Buddha was asked one time if there was a self or not, he point blank refused to answer the question. I think what he was trying to teach us, is the self is not what we think it is. It is not the things that we identify with and call the self. There is no permanent fixed soul that travels through existence like a marble on a marble run. There is no marble. There is just flow with nothing substantial behind it. Just changing streams of energy, of processes that arise and cease due to causes and conditions.
But it is also not true to say that nothing exists. Because there is energy, energy is real, in physics, we are taught that energy is neither created nor destroyed, only converted from one form of energy to another. So where did that energy come from originally and what happens to it at death?
The Buddha said no matter how far back in time he looked, he could not find a beginning to this mysterious flow of energy we call life. And when someone asked him what happens to a fully enlightened being (an arahant) after death, he didn't give an answer, he said such questions are unknowables, at least to those of us who are not arahants. He taught that pondering such things can be a waste of time, and can't be put in words satisfactorily. These unknowables can get in the way of practising what is important. Which is what is in front of us in the here and now. Our lives are brief, and the only really important question is am I suffering or not? The goal of the Buddhist path is to realise complete lasting freedom from suffering. The third noble truth. This is the greatest supernormal power, the greatest knowledge of all.
Still, in an attempt to satisfy my curiosity. I tend to think of it like this. Imagine the energy we call self is like a glass of water. And nibanna, the deathless, the unconditioned element, is like a peaceful ocean that is not affected by weather, currents, change or any other phenomena. What happens to the water in the glass when it is poured into that ocean? Where does it go and what does it become?
Peace and light