Jiva and ajiva

Jiva

Jiva is the soul, and Jain doctrine holds that souls are infinite in number, individually eternal, and each intrinsically possessed of consciousness, knowledge and bliss. A soul is not a spark of a universal spirit, as in some Vedantic accounts; it is a distinct individual that remains distinct after liberation. It has no fixed size but expands or contracts to fill the body it occupies.

Souls are graded by the number of senses they possess. At the lowest are the ekendriya, one-sensed beings, which include plants and the elemental bodies of earth, water, fire and air; above them two-, three- and four-sensed creatures; then five-sensed animals, humans, hell-beings and gods. This gradation carries the ethical weight of the tradition, since harm to a being with more senses binds more heavily.

Ajiva

Ajiva is everything without consciousness. It comprises matter, which is atomic and includes karmic particles; space, which is infinite and gives things their place; the medium of motion and the medium of rest, two principles peculiar to Jain physics which make movement and stillness possible without themselves causing them; and time.

The medium of motion and rest are the tradition's most distinctive contribution to Indian natural philosophy. They function rather as a condition than a cause — water is the medium in which a fish swims but does not propel it — and they are used to explain why the liberated soul rises to the summit of the universe and stops there, at the boundary beyond which no medium of motion exists.

Their interaction

Bondage is the adherence of one kind of ajiva, karmic matter, to jiva. Everything else in Jain doctrine follows: the influx that must be stopped, the accumulation that must be worn away, and the liberation in which soul and matter finally separate. The seven or nine tattvas of the Tattvartha Sutra set out this sequence as the whole content of what must be known.