Kamma necessarily leads to rebirth. Past Kamma conditions the present birth, and present Kamma, in combination with past Kamma, the future. The present is the offspring of the past, and becomes, in its turn, the parent of the future.

The present needs no proof. The past is based on memory and reports, and the future on forethought and inferences.
 

REASONS TO BELIEVE IN A PAST BIRTH

The greatest authority on rebirth is the Buddha.
 

Says He:

“With clairvoyant vision, purified and supernormal, I perceived beings disappearing from one state of existence and re-appearing in another. I beheld the base and the noble, the beautiful and the ugly, the happy and the miserable, passing according to their deeds.”

There were no reasons for the Buddha to tell an untruth to deceive His followers. Following His instructions His disciples also developed this retrocognitive knowledge and were able to read their past lives to a great extent.

The development of this supernormal vision is not restricted only to the Buddha and His disciples. Any person, whether Buddhist or not, could possess this faculty.  Some Indian Rishis, even before the advent of the Buddha, developed such powers as clairaudience, clairvoyance, thought reading, and so forth.

There are also some persons who, according to the laws of association, spontaneously develop the memory of their past birth and remember fragments of their previous lives. A few well-attested cases are reported from Burma, India, Germany, England, etc.

Extraordinary experiences of some modern reliable psychists and strange cases of alternating and multiple personalities tend to throw light upon this belief in rebirth.

This phenomenon of secondary personalities has to be explained either as remnants of past individual experiences or as “being possessed”. The former explanation sounds more reasonable, but the latter cannot totally be discarded.

In hypnotic states some can relate experiences of their past lives; while a few others, like Edgar Casey of America, were able not only to read the past lives of others but also to heal diseases.

Sometimes we go through strange experiences, which cannot be explained but by rebirth. How often do we meet persons whom we have never before met and yet inwardly feel that they are quite familiar to us? How often do we visit new places and yet feel impressed that we are perfectly acquainted with their surroundings?

In this world there arise Perfect Ones like the Buddhas, highly developed personalities. Could they evolve suddenly? Could they be the products of a single existence?

How are we to account for colossal characters like Confucius, Pamini, Homer and Plato, men of genius like Kalidasa, Shakespeare, infant prodigies like Ramanujan, Pascal, Mozart, Beethoven, Raphael, and others, and little children conversant with different languages and certain subjects which they had never learnt in their present life?’

Heredity alone cannot account for them, “else their ancestry would disclose it, their posterity, even greater than themselves, demonstrate it.” Could they arise to such lofty heights if they had not lived such noble lives and gained similar experiences in the past? Is it by mere chance that they are born of those particular parents and placed under those favourable circumstances?

The theory of heredity should be supplemented by the doctrine of Kamma and rebirth for an adequate explanation of these puzzling problems. Is it reasonable to believe that the present brief span of life is the only existence between two eternities of heaven and hell?

The few years we are privileged to spend here, for the most five score years, must certainly be an inadequate preparation for eternity. If one believes in the present and in future, it is quite logical to believe in the past.

If there be reasons to believe that we have existed in the past, then surely there are no reasons to disbelieve that we shall continue to exist after our present life has apparently ceased. It is indeed a strong argument in favour of past and future lives that “in this world virtuous persons are very often unfortunate and vicious persons prosperous.”

Some discoveries of modern spirituals also tend to prove the existence of a future birth.
 

THE CAUSE OF THIS REBIRTH PROCESS-THE WHEEL OF LIFE

In short, Kamma, which is rooted in Ignorance, is the cause of birth and death. As long as this Kammic force survives there is rebirth. This process of becoming is fully explained in the Paticca Samuppada - Dependent Arising or Dependent Origination.

It should be understood that Paticca Samuppada is only a discourse on Samsara or the process of birth and death and not a theory of the evolution of the world from primordial matter. It deals with the cause of rebirth and suffering, but it does not attempt to show the absolute origin of life.

Ignorance - Avijja, of the Four Noble Truths is the first link or cause of the wheel of life. It clouds all right understanding.

Dependent on ignorance arises volitional activities (Sankhara).
Moral and immoral activities, whether good or bad, which are rooted in ignorance, tend to prolong wandering in Samsara.

Nevertheless, good actions are essential to get rid of the ills of this ocean of life.
Dependent on Volitional Activities arises Relinking Consciousness - Vinnana. This links the past with the present.

Simultaneous with the arising of Re-linking Consciousness there come into being Mind and Matter - Nama and Rupa.

The Six Senses - Salayatana, are the inevitable consequences of Mind and Matter. Because of the Six Senses Contact - Phassa, sets in.

Contact leads to Sensations - vedana,

Dependent on Sensations arises Craving - Tanha.

Craving produces Attachment - Upadana.

Attachment conditions Kamma - Bhava, which in its turn determines future Birth - Jati.

Old  Age  and  Death  - Jara-Marana  are  the inevitable consequences of birth.
If, on account of a cause, an effect comes to be, then if the cause ceases, the effect also must cease. The complete cessation of Ignorance leads to the cessation of birth and death.

The above process of cause and effect continues ad infinitum. The beginning of this process cannot be determined, as it is impossible to say whence this life-flux was encompassed by ignorance. But when this ignorance is turned into knowledge and the life-flux is transmuted to Nibbana Dhatu, then the end of the life process or Samsara comes about.
 

MODES OF BIRTH AND DEATH

Buddhism assesses death to the following four causes:-
 

1. The exhaustion of the force of Reproductive Kamma that gives rise to the birth in question - Kammakkhaya.

The Buddhist belief is that, as a rule, the thought, volition, or desire which is extremely strong during lifetime, becomes predominant at the point of death and conditions the subsequent birth. In this last thought-moment is present a special potentiality.  When the potential energy of this Reproductive Kamma is exhausted, the corporealised, the life-force, cease even before the approach of old age.

2. The expiration of the life-term - Ayukkhaya.

What are commonly understood to be natural deaths due to old age may be classed under this category. There are various planes of existence according to Buddhism, and to each plane is naturally assigned a definite age-limit. Irrespective of the Kammic force that has yet to run, one must, however, succumb to death when the maximum age-limit is reached. It may also be said that if the force is extremely powerful, the Kammic energy rematerialises itself on the same plane or in some higher realm as in the case of the Devas.

3. The simultaneous exhaustion of the Reproductive Kammic energy and the expiration of the life-term - Ubhayakkhaya.

4. The action of a stronger Kamma - Upacechdaka that suddenly cuts off the power of the Reproductive Kamma before the expiry of the life-term.

The first three types of deaths are collectively called Kalamarana (timely death) and the last one is known as Akalamarana (untimely death).

An oil lamp, for instance, may get extinguished owing to any of the following four causes:- the exhaustion of the wick, the exhaustion of oil, simultaneous exhaustion of both wick and oil, and some extraneous cause like a gust of wind.

The death of a person may similarly be caused by the above-mentioned four ways.
 

THE FOUR MODES OF BIRTH

The four Modes of Births are:-
 

1. Egg-born creatures - Andaja, such as birds, snakes, etc.

2. Womb-born creatures  - Jalabuja. All human beings, some earth-bound deities, and  those  animals  that  take their conception in mother’s womb, belong to this class.

3. Moisture-born creatures - Samsedaja, such as certain insects that take moisture as material for their growth.

4. Creatures having spontaneous births - Opapatika. They are generally invisible to the naked eye. Conditioned by past they appear suddenly,  independent of parents. Brahmas, Devas of heavenly realms, Petas, and miserable ones who are subject to torments and sufferings in states of woe - Niraya are included in this class.

There are 31 Planes of Existence. They are:-
 

(A) The Four States of Unhappiness - Duggati, viz.,

1. Niraya - woeful states, which are temporary, but not everlasting.
2. Tiracchana Yoni - the animal Kingdom.
3. Peta Yoni - the plane of Petas or ghost-beings.
4. Asura Yoni - the plane of Asura demons.

(B) The Seven Happy States - Sugati, viz.,

1. Manussa - the realm of human beings.
2. 6 Devalokas - heavenly realms.
3. 16 Rupalokas- Realms of Form.
4. 4 Arupalokas- Formless Realms.
 

HOW REBIRTH TAKES PLACE

To the dying man is presented a Kamma, Kamma Nimitta,  or  Gati  Nimitta.  By ,Kamma  is here meant some action of his whether good or bad. It may be either a meritorious or a demeritorious Weighty Action - Garuka Kamma, such as Jhanas - Ecstasies, or parricide, and so forth.

These are so powerful that they totally eclipse all other actions and appear very vividly before the mental eye. If experience has afforded him nothing weighty, he may take for the object of his dying-thought a Kamma done immediately before death - Asanna Kamma.

In the absence of an Asanna Kamma, a habitual meritorious or demeritorious act (Acinna Kamma) is presented, such as stealing in the case of a robber, or the healing of the sick in the case of a good physician. Failing all these, some casual act, that is, one of the accumulative reserves of the endless past - Katatta Kamma, becomes the object of the dying thought. Kamma Nimitta is any sight, sound, smell, taste, touch, or idea which was obtained at the time of the commission of the Kamma, such as knives in the case of a butcher, patients in the case of a physician, an object of worship in the case of a devotee, etc.

By Gati Nimitra is meant some sign of the place where one is destined to be reborn - an event, which invariably happens to dying persons. When these indications of the future birth occur, if they are bad, they could be turned into good. This is done by influencing the thoughts of the dying man, so that his good thought may now act as the proximate Kamma and counteract the influence of the Reproductive Kamma which would otherwise affect his subsequent birth.

These symbols of one’s destiny may be hellish fires, forests, mountainous re ions, a mother s womb, celestial mansions, etc.

Taking for the object of the dying-thought one of the above, a thought process runs its course even if the death be an instantaneous one. It is said that even the fly which is crushed by a hammer on the anvil also experiences such a process of thought before it actually dies.

By death is meant the ceasing of the psycho-physical life of one’s individual existence. Death takes place by the passing away of vitality - Ayu, heat - Usma and consciousness - Vinnana.

In the words of a Western philosopher death is merely “the temporary end of a temporary phenomenon.” It is not the complete annihilation of the so-called being, for, although the organic life has ceased, the force, which hitherto actuated it is not destroyed.

Just as an electric light is only the outward visible manifestation of invisible electric energy, even so we are only the outward manifestations of invisible Kammic energy. The bulb may break and the light may be extinguished, but the current remains and the light may be reproduced in another bulb.  At the death the consciousness perishes only to give birth to another consciousness in a subsequent birth. This renewed life-flux inherits all past experiences.

This new being is neither absolutely the same as the past one owing to its different composition, nor totally different - being the identical stream of Kammic energy - Na ca so na ca anno.

The birth-process of the butterfly may be cited in illustration of this. It was first an egg, and then, it became a caterpillar. Later it developed into a chrysalis, and finally evolved into a butterfly. This process occurs in the course of one lifetime. The butterfly is neither the same as, nor totally different from, the caterpillar. Here too there is a flux of life or continuity.

The transition of the flux is also instantaneous. There is no room for an intermediate state - Antara bhava. Buddhists do not believe that the spirit of the deceased person takes lodgement in a certain state until it finds a suitable place for its reincarnation.

Rebirth takes place immediately, and there is no difference in time whether one is born in a heaven or in a state of misery, as an animal or as a human being.
 

WHAT IS IT THAT IS REBORN?

According to Buddhism, apart from mind and matter, which constitute this so-called being, there is no immortal soul or an eternal ego which man is either gifted with or has obtained in a mysterious way from a mysterious Being or force.

The Buddhist doctrine of rebirth should be distinguished from the theory of re-incarnation or transmigration, for Buddhism denies the existence of an unchanging or eternal soul. In the ultimate sense a Buddhist cannot think of an unchanging soul, any being in the form of a Deva, a man, or an animal. These forms are merely the temporary manifestations of the Kammic force.

“Being” is only a concept used for conventional purposes. If nothing in the form of a spirit or soul passes from this life to the other, what is it that is reborn? In asking this question one takes for granted that there is something to be reborn.

In the past it was argued - “Cogito, ergo sum - I think, therefore I am.” True indeed, but it has to be proved first that there is an 'I' to think. I say that there is no I to think. In one breath I contradict myself. Yes, it has to be admitted that we cannot avoid using conventional terms we say that the sun rises in the east and sets in the west despite what scientists prove to us.

We cannot strike a place twice although to all appearance we have done so. Everything has changed so soon. Even space has changed at the second moment.
According to Buddhism the so-called being is composed of mind and matter - Nama and Rupa.

Rupa or matter is merely the manifestation of torces and qualities. In the ancient days the Indian sages too believed in an indivisible atom - Paramanu. The Buddha analysed this so-called indivisible Paramanu and declared that it is only a manifestation of inter-related forces, which he termed Paramatthas or fundamental units of matter.

These Paramatthas are Pathavi, Apo, Tejo, and Vayo. Pathavi means the element of extension, the substratum of matter. Apo is the element of cohesion. Tejo is the element of heat. Vayo is the element of motion.

The four essentials of matter are invariably combined with four derivatives, colour - Vanna, odour - Gandha, taste - Rasa and nutritive essence Oja. The four elements and the derivatives are inseparable and inter-related, but one element may preponderate over the other, for instance, the element of extension predominates in earth; cohesion in water, heat in fire, and motion in air.

Mind, which is the most important part in the machinery of man, is also a compound of fleeting mental states. There are fifty-two such mental states.  Vedana or sensation is one, Sanna or perception is another. The remaining fifty mental states are collectively called Sankharas or volitional activities. These immaterial states arise in a consciousness - Vinnana.

Thus the so-called being is a complex compound of five Aggregate - Pancakkhandha - namely, Rupa or matter, Vedana or sensations, Sanna or perceptions, Sankhara or mental states, and Vinnana or consciousness, which are in state of constant flux.

One’s individuality is the combination of these five Aggregates. There is no permanent soul that resides in this so-called being.
 

HOW IS REBIRTH POSSIBLE WITHOUT A SOUL TO BE REBORN?

Birth is simply the arising of the Khandhas, the aggregates Rebirth is the arising of the aggregates again and again. Just as the arising of a physical state is conditioned by a preceding state as its cause, even so the coming-into-being of this psycho-physical life is conditioned by causes anterior to its birth. As one life-process is possible without a permanent thing passing from one thought-moment  to another, a series of life-processes is possible without anything to transmigrate from one life to another.

This body - to use conventional terms - dies transmitting its Kammic force to another without anything transmigrating from this life to the other. The future being there will be conditioned by the present Kamma here. The new being is neither absolutely the same as its predecessor - since the composition is not identical - nor entirely another being the same stream of Kammic energy. There is, therefore, a continuity of a particular life-flux; just that and nothing more.