Kaivalya — Aloneness, the Absolute Freedom of Pure Consciousness
Kaivalya (liberation, aloneness) is Patanjali's term for the final state of the Yoga Sutras: pure consciousness (Purusha) recognized as eternally free, alone in its own nature, forever untouched by the fluctuations of Prakriti.
Sutra 4.34 — the final sutra — defines Kaivalya: 'purusha artha shunyanam gunanam pratiprasavah kaivalyam svarupa pratishtha va chiti shaktir iti.' Kaivalya is the return of the gunas to their unmanifest state, now that they have fulfilled their purpose for Purusha — or alternatively, it is the establishment (pratishtha) of the power of consciousness (chiti shakti) in its own nature (svarupa). Two images of liberation: the world returning to its ground, or consciousness recognizing its own nature. Both point to the same reality: the apparent entanglement of consciousness with the play of Prakriti is seen through, and what was always the case — the freedom, purity, and aloneness of pure consciousness — is permanently recognized. This is Yoga's Nirvana, its moksha, its enlightenment.
The return of the gunas to their source, now that the Purusha's purpose is fulfilled, or the establishment of the power of consciousness in its own nature — this is liberation.
Sri Ramana Maharshi's description of moksha as 'the recognition of what was always the case' perfectly captures Patanjali's Kaivalya: liberation is not a new state to be achieved but the recognition of the Purusha's eternal freedom that was temporarily obscured by identification with Prakriti.
Yoga Sutras of Patanjali