"We have seen earlier that a being is nothing but a combination of physical and mental forces or energies. What we call death is the total non-functioning of the physical body. Do all these forces and energies stop altogether with the nonfunctioning of the body? Buddhism says 'No'. Will, volition, desire, thirst to exist, to continue, to become more and more, is a tremendous force that moves whole world lives, whole existences, that even moves the whole world. According to Buddhism, this force does not stop with the non-functioning of the body, which is death; but it continues manifesting itself in another form, producing re-existence which is called rebirth.
"Now, another question arises: If there is no permanent, unchanging entity or substance like Self or Soul (atman), what is it that can re-exist or be reborn after death?
"Before we go on life after death, let us consider what this life is, and how it continues now. What we call life, as we have so often repeated, is the combination of the Five Aggregates, a combination of physical and mental energies. These are 24 constantly changing; they do not remain the same for two consecutive moments. Every moment they are born and they die. 'When the Aggregates arise, decay and die, O bhikkhu, every moment you are born, decay and die.'
"Thus even now during this life time, every moment we are born and die, but we continue. If we can understand that in this life we can continue without a permanent, unchanging substance like Self or Soul, why can't we understand that those forces themselves can continue without a Self or Soul behind them after the nonfunctioning of the body? When this physical body is no more capable of functioning, energies do not die with it, but continue to take some other shape or form, which we call another life. In a child all the physical, mental and intellectual faculties are tender and weak, but they have within them the potentialitiy of producing a full grown man. Physical and mental energies which constitute the so- called being have within themselves the power to take a new form, grow gradually and gather force to the full.
"As there is no permanent, unchanging substance, nothing passes from one moment to the next. So quite obviously, nothing permanent or unchanging can pass or transmigrate from one life to the next. It is a series that continues unbroken, but changes every moment. The series is, really speaking, nothing but movement. It is like a flame that burns through the night: it is not the same flame nor is it another. A child grows up to be a man of sixty. Certainly the man of sixty is not the same as the child of sixty years ago, nor is he another person.
"Similarly a man dies here and reborn elsewhere is neither the same person, nor another. It is the continuity of the same series. The difference between death and birth is only a thought-moment: the last thoughtmoment of this life conditions the first thought-moment in the so-called next life, which in fact, is the continuity of the same series. During the life itself, too, one thought-moment conditions the next thought-moment. So, from the Buddhist point of view, the question of life after death is not a great mistery, and a Buddhist is never worried about this problem. As long as there is this 'thirst' to be and to become, the cycle of continuity (samara) goes on. It can stop only when its driving force, this 'thirst', is cut off through wisdom which sees Reality, Truth, Nirvana.