Reincarnation in Hinduism in General
Karma: the Cause of Reincarnation
According to the Hindu religious and philosophical concepts, man is composed of two fundamental principles opposed to each other per nature: one spiritual, the soul (atman), and the other material, the body (sarira). The atman is eternal, immutable, not born, not created, indestructible; instead, the body is temporal, created, mutable, destructible. The union between atman and body is not essential, but is accidental It is a type of imprisonment or a penalty which the atman has to undergo due to avidya and karma, to which it is associated from all eternity. Avidya and karma are two basic presuppositions of Hinduism. They have no beginning because they did not have a beginning. It is therefore a truth that transcends every intellectual explanation.
Avidya signifies ignorance, ignorance of the true nature of atman or of the distorted vision in which the atman identifies itself or confounds itself with the psycho-physical organism. Due to avirlya, the atman which is eternal and non-temporal, is caught up in time; gets joined to physical body. Birth is the union of the eternal and spiritual atman with the material and temporal body.

Karma-Samsara
The nature of birth, that is, the condition of the body to which the atman gets united, depends on karma. Karma (Pali, Kamma, Tib., las; Chin., yeh or yin-k1lo; Jpn., go or inga), based on the Sanskrit verbal root he, signifies action, every sort of action, whether good or bad, meritorious or non-meritorious, religious or worldly; here, however, karma signifies the moral debit of the actions which one has done. Every action inevitably produces its own fruit (phala), and the subject (actor) has necessarily to experience all the consequences of his own actions. A person's behavior leads irrevocably to an appropriate reward or punishment commensurate with that behavior.6 It is the inevitable law of retribution or the law of karma. It is the law of cause and effect applied to the life of every individual, law according to which every one gathers the fruit of what one has sowed or undergoes the effect of his own actions.
The effects of all the actions which a person does cannot be experienced (lived) during one single existence, because while the subject (actor) experiences the fruit of some act, does other actions in the meantime, and therefore gains new fruits which have to be exper~enced. From this fact is deduced that the atman (soul) has to be reborn repeatedly. So it is believed that the soul from all eternity is undergoing birth and rebirth due to this inviolable law of karma. Thus is born the doctrine of the transfiguration of the soul. It is a corollary of the doctrine of karma.
The entire process of reincarnation of the soul according to the law of karma is called Karma-samsara. Samsara means "to wander or pass through a series of states or conditions." Samsara is the beginning-less cycle of birth, death, and rebirth, a process impelled by karma.8 Life, therefore, is not determined or limited to one birth and one death, but is instead a samsara, a current, a course, a migration in circle, which however is always determined by the law of karma. In short, human life is a karma-samsara, a transmigration of the soul according to the inevitable law of retribution.

The Subtle Body
In order to explain how the effects of past actions of man are preserved in the atman after the death of the body and how these effects produce their fruit in a future rebirth, the Hindu theologians make a distinction between two types of body: the gross body (sthula-sarira) and the subtle body (sukshma-sarira or linga- sarira).9 The gross body is that which is visible and tangible, consists of the eternal senses, of organs, etc. The subtle body, instead, is not visible nor tangible, and is composed of subtle elements, like: budclhi (intelligence), manas (mind), ahamkara (ego), etc.'° The subtle body encircles the atman and se~ves as a connection between the soul and the gross body. Every action of man leaves its imprint (samskara) on the subtle body and remains as a seed which has to mature and produce in due time its proper fruit.11 While the gross body disintegrates at death, the spirit continues to be in contact with the subtle psychic body which it carries forward. The subtle body together with all the tendencies, merits or effects of karma is said to migrate with the soul (atman) at death.