From a Jain perspective:

• What is soul (jiva)? Jiva is the eternal, conscious, individual principle that experiences pleasure and pain. It is not the body, mind, or senses, but the observer/experiencer inside.

• What counts as evidence in Jainism?

- Direct perception (pratyaksha): In yogic experience, a liberated or highly realized being can directly perceive the soul’s nature. For ordinary people, the soul’s presence is not seen with external eyes, but is understood through inner experience and consistency with experience of varying states of consciousness (happiness, suffering, awareness). - Testimony of enlightened ones: The teachings of the Tirthankaras and other liberated souls are taken as valid evidence about the nature of jiva, karma, and liberation. - Logical inference (anumana) about cause and effect: We observe that actions (karma) cause changes in experience and body; since the self seems to persist through changing bodies and experiences, it is understood as a permanent, non-material agent (the jiva) that is distinct from the body. - Experiential consistency: Across many lives, the continuity of “I” and personal identity, along with the ability to experience inner states (feeling, intention, awareness) supports the Jain view of a persistent soul.

• How Jainism treats evidence of soul for different traditions:

- Digambara and Śvētāmbara agree on the existence and essential nature of the jiva (the soul) as pure, conscious, and bound by karma. - Differences, if any, are about metaphysical nuances or scriptural details, not about whether the soul exists.

• Important caveat:

- Jain epistemology does not rely on external scientific demonstration in the modern sense. The reliable knowledge about jiva comes from a disciplined practice, scriptural testimony of enlightened beings, and coherent inference about the nature of karma and experience.

If you want, I can outline the core Jain definitions of jiva, ajiva, and karma in simple terms, or explain how different Jain sources describe the soul’s qualities and its liberation.