According to Hinduism, birth and death are a continuously revolving wheel. A soul is inculcated into an embryo according to the knowledge level of the soul and the kind of deeds the soul had performed in the previous embodiment. Again, there are several aspects here. The question of whether the soul can perform deeds out of freewill or is it bound by its past actions, is raised. It should be possible to do acts out of freewill, because, only then the soul can gather new types of karma, which may take it to higher or lower levels of knowledge. So, in this manner, the soul can either finally be freed from this cycle of birth and death by attaining to highest levels of knowledge, or deplete its knowledge by base thoughts and actions, leading to downfall. If the soul's level of knowledge falls so low as to take it into the lowest animals, like reptiles, amphibians, insects, then there is no escape for such a soul. This is because endowed with brains and minds of such low capacity, the soul's level of knowledge can never increase. So, it keeps migrating from one body to another indefinitely.
That is why Hindu philosophy emphasizes that this human life is very precious. We never know when again we may get this chance. If we increase our knowledge now, we might have another human life and get a further chance to improve. However, if we waste our time, we may fall lower and lower.
Answered by
Shishir
at
11:04 PM on October 16, 2008