The Yoga Sutras of Patanjali: Book IV

In the final book of the Yoga Sūtras called Kaivalya Pāda, Patañjali reveals the nature and implications of liberation (kaivalya). Kaivalya means complete isolation: the isolation of puruṣa or higher consciousness from prakṛti or nature or matter. This is the isolation of the Self in itself, free from ignorance and dualistic notions.