Patanjali Yoga Sutra: II - 25

The cause disappears together with the effect!

Tad Abhavat Samyoga Abhavo Hanam Tad Drisheh Kaivalyam

When the veil of ignorance that separates the one who sees, the Purusha, from all that is perceived by the five senses - prakriti, drops with the constant practice of yoga - then the duality of this world also leaves. When the sun of awareness shines brightly, the darkness of ignorance or avidya that creates a non-existent division between the subject and object vanishes by evaporation. When there is no duality - there is nothing to separate the purusha from the prakriti - the light alone remains. This sense of separation which is the adi vyadhi or the primordial disease is dissolved - that state of mind is called Kaivalya or a liberated being. - Swahilya Shambhavi