Karma is the sum-total of works-good, bad and mixed-which an individual performs during his life. It is the collective totality of man's actions. It is these actions that determine his future existence. There is double retribution or reward for man's virtuous actions. He gets a good birth with suitable surroundings, environments and opportunities for his good actions: this is one reward. Another reward is that he gets a place in the abode of heaven also. But after the consummation of happiness he is sure to be hurled back to this physical plane. Lord Krishna says in the Gita:
They, having enjoyed the spacious heaven world, their holiness withered, come back to this world of death. Following the virtues enjoined by the three (Vedas) and desiring objects of desires, they attain to the state of coming and going."
It is very difficult to say what Karma brings forth a particular disease. Is it a single Karma or a combination of several Karmas that brings epilepsy? The sages declare that the theft of a golden necklace brings Scrofula in the neck in the next birth. They say that leprosy, epilepsy and gulma (chronic gastric catarrh) are due to very bad Karmas. It is also difficult to say whether this body is the resultant product of a single Karma or a mixture of several Karmas. Generally one strong and powerful Karma determines the birth of an individual and keeps up the current of life of that particular birth. Some minor Karmas may be joined to the main trunk or the central thread. Learned persons say that one will have to take several births sometimes to exhaust the fruits of one important virtuous Karma. The secret of Karma is very mysterious. God only knows them because He is the Law-giver. Sometimes highly virtuous and vicious Karmas bring forth their fruits in the very life itself.
It is impossible for a man to remain without doing any action either through the organs of action, feet, hand, etc., or through the mind. Even if he becomes a Sannyasin and retires into the cave in the Himalayas he must continue eating, drinking, answering the calls of nature, sleeping, etc. That is the reason why the Lord says in the Gita: "Nor can anyone, even for an instant remain really actionless; for helplessly is everyone driven to action by the qualities born of nature." Ch. III-5.
If work ceases to produce rebirth, literally no one can be freed. To avoid this difficulty knowledge is credited with powers of destroying Karmas. The Gita says:
Jnanagnih sarvakarmani bhasmasatkurute.
"The fire of wisdom reduces all actions to ashes." Ch. IV-37.
To sum up in a nutshell: there are three kinds of Karmas, viz., the Sanchita or accumulated ones, the Prarabdha or the fructiferous, and the Agami or current actions. Sanchita are works which have been accumulated in several previous births; Prarabdha are those which have given the present life and have already started to bear fruit; and Agami are the works which are being done in this present life. They will bring fruits in a future life. The Sanchita and Agami are destroyed by getting Brahma Jnana or knowledge of the Self or God. But the Prarabdha can only be exhausted by experiencing their fruits in the present life. A child is born blind, deaf or dumb-this is due to Prarabdha. One man dies at the age of ninety, another at thirty-five and the third at eighteen: this is due to Prarabdha. Jati (caste), longevity of life, Bhoga (enjoyment), are all due to Prarabdha. A virtuous man suffers, he is starving. A scoundrel is in a prosperous condition. An aged mother loses her only son who was her sole prop. A young girl who was newly married loses her husband. Instances like these can be multiplied ad infinitum. In all these cases Prarabdha operates unerringly with scientific accuracy and precision.
See how Prarabdha operates. A lady from Paris came to me for an interview. She said that ever since she landed in India she was quite at home in the country. India was very familiar to her. She liked India and Indians very much. Within three months she forgot all about her parents and native place. She liked the Indian way of dressing. So she changed her dress. She wanted to domicile in India for the practice of Yoga. This clearly shows that in her previous birth she was born in India. Another American lady lived in Lakshman Jhula near Rishikesh fifteen years ago. She lived on Bhiksha, led the life of an ascetic and died on the banks of the Ganga. This is all Prarabdha. Hindus say that wherever there is Anna-Jala (food and drink) for a man, there he will be dragged. You cannot remain in a place even for a second more, when the Anna-Jala is finished.
The last powerful thought that occupies the mind of a man in his dying moment determines the nature of his next birth. You will find in the Gita:
Yam yam vaapi smaran bhavam tyajatyante kalevaram
Tam tamevaiti Kaunteya sadaa tadbhavabhavitah.
"Whosoever at the end abandoneth the body, thinking upon any being, to that being only he goeth, O Kaunteya, ever to that confirmed by nature." Ch. VIII-6.
If the thought of tea comes in your mind at the moment of death, you may become a manager of a tea estate in the next birth, if you had done virtuous actions, or you may be born to do hard labour in a tea estate if you had done any evil actions. A drunkard will have thoughts of liquor when he is dying. A licentious man will think of women only when he is about to expire. I saw a dying man who had the habit of using snuff. When he was in an unconscious state he used to move his fingers towards the nose every now and then and do imaginary snuffing. Obviously he had thoughts of snuff. A medical officer of a hospital used all sorts of abusive terms while he was in a dying condition. Raja Jada Bharata, out of compassion for a deer took great care of the animal. He gradually developed attachment. The one thought of the deer only occupied his mind when he was about to die. So he had to take the birth of a deer. In every Hindu home the Names of God, such as Hari Om, Ram, Ram Narayan and Krishna are whispered into the ear of the dying man. The idea is that the dying man may remember the Name and form of the Lord and thereby reach the blissful abode. If a man leads a virtuous life for many years, and if he does Japa and meditation for a long time, then only, through the force of habit he will remember God and His Name at the moment of death.
Hindu scriptures say that a man may become a Deva or a beast or a bird or vegetable or stone according to his merit or demerit. The Upanishads also corroborate this statement. Kapila also agrees on this point. But Buddhism and some Western philosophers teach: 'There is no more retrogression for a man when once he takes a human birth. There is no necessity for him to be born as an animal for the sake of demerit. He can be punished in a variety of ways in the human birth itself.' When a man takes the form of a Deva, all human Samskaras, habits and tendencies will remain dormant. When a man takes the form of a dog, the animal-tendencies, habits and Samskaras only will manifest. Human tendencies will remain suppressed. Some dogs get royal treatment in the palaces of kings. They move in cars, eat good food and sleep on cushions. These are all degenerated human beings.
After death this physical body, composed of five elements, is cast off like a slough or the coil of a snake. The inner astral body or Linga Sarira, which consists of nineteen Tattvas, viz., five Karma Indriyas, five Jnana Indriyas, five Pranas, mind, Buddhi, Chitta and Ahamkara, goes to heaven, comes back to the physical plane, puts on another physical body and reincarnates. It is this body that contains the impressions of Karmas. This body remains till one gets knowledge of the Self and consequent emancipation. Then it disintegrates and the components get involved in the ocean of Tanmatras or Avyaktam.
Heaven and hell are mental creations only. It is the mind that makes a heaven of hell and a hell of heaven. They are Puranic concepts. For a Vedantin there is neither hell nor heaven. Who is to suffer? The Atman is Akarta or Nishkriya. The Atman is all-pervading. It is ever free (Nitya Mukta).
Works are extinguished either by expiatory ceremonies (Prayaschitta) or by the knowledge of the Self or Brahman, or by the full fruition of their consequences.
Smritis declare that some single actions such as the murder of a Brahmin, are the causes of more than one new existence.