Krsna on the Soul

Witness, source of the consent, upholder of the work of Nature, her enjoyer, almighty Lord and supreme Self is the Supreme Soul seated in this body.... He who sees that all action is verily done by Nature, and that the Self is the inactive witness, he sees. When he perceives the diversified existence of beings abiding in the one eternal being, and spreading forth from it, then he attains to Brahman. Because it is without origin and eternal, not limited by the qualities, the imperishable supreme Self, though seated in the body, O Kaunteya, does not act, nor is affected As the all-pervading ether is not affected by reason of its subtlety, so seated everywhere in the body, the Self is not affected As the one sun illumines the entire earth, so the Lord of the Field illumines the entire Field, O Bharata. They who with the eye of knowledge perceive this difference between the Field and the Knower of the Field and the liberation of beings from Nature, they attain to the Supreme.

Bhagavad-Gita, XIII:23, 30-35